CN113726377B - A phase compensation, calibration method and AP - Google Patents

Abstract

Provided are a phase compensation method, a calibration method and an AP, wherein the phase compensation method comprises the following steps: and the AP receives the radio-frequency signals from the STA through a plurality of radio-frequency links, measures the radio-frequency signals and obtains a downlink equivalent channel matrix of the channel from the AP to the STA according to a plurality of phase compensation values. The phase calibration method comprises the following steps: the AP processes a first radio frequency signal transmitted by a second radio frequency link by using a first radio frequency link in a first state to obtain a first baseband signal; and the AP determines a single-device phase compensation value when the first gain device is in the gear to be measured according to the first baseband signal and the second baseband signal. The technical scheme is used for improving the accuracy of predicting the downlink equivalent channel matrix by the AP.

Description

A phase compensation, calibration method and AP

technical field

The present application relates to the field of communication technologies, and in particular, to a phase compensation and calibration method and an access point (AP).

Background technique

Beamforming (beamforming, BF) realizes the transmission or reception of directional signals through precoding technology, and BF can be divided into two categories: implicit BF (implicit beamforming, IBF) and explicit BF (explicit beamforming, EBF). In wireless local area network (WLAN), IBF is an important method for closed-loop multiple-input multiple-output (MIMO) system to improve air interface performance, which can avoid EBF in the station (station, STA) side channel Measure the dimensionality loss and reduce the air interface interaction overhead.

In the closed-loop MIMO system based on IBF, the AP receives the signal from the STA, and performs channel estimation according to the received signal, so as to obtain the uplink equivalent channel matrix from the STA to the AP. Based on the channel reciprocity, the AP predicts the downlink equivalent channel matrix from the AP to the STA, generates a precoding matrix according to the downlink equivalent channel matrix, and then determines the transmission signal of each radio frequency chain (chain) to the STA according to the precoding matrix.

However, RF links exist in both APs and STAs. When the RF links process signals, RF delays occur, and the RF delays cause signal phase jumps. The AP performs channel estimation based on the phase hopping signal, which affects the accuracy of the AP's prediction of the downlink equivalent channel matrix.

SUMMARY OF THE INVENTION

The present application provides a phase compensation and calibration method and an AP, which are used to improve the accuracy of the AP's prediction of a downlink equivalent channel matrix.

In a first aspect, the present application provides a phase compensation method, the method comprising:

The AP receives radio frequency signals from the STA through multiple radio frequency links, each of the multiple radio frequency links includes at least two gain devices;

The AP measures the radio frequency signal and obtains a downlink equivalent channel matrix of the channel from the AP to the STA according to a plurality of phase compensation values, where the downlink equivalent channel matrix is from the STA to the AP The transpose of the uplink equivalent channel matrix of the channel, the relationship between the multiple phase compensation values and the multiple radio frequency links is one-to-one correspondence, the uplink equivalent channel matrix includes multiple row vectors, the multiple The relationship between each row vector and the multiple radio frequency links is one-to-one correspondence, and each row vector of the uplink equivalent channel matrix is adjusted by the phase compensation value of the corresponding radio frequency link. Among the multiple phase compensation values Each phase compensation value of is determined based on the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency chain.

Based on the above technical solutions, the AP receives the radio frequency signal from the STA through each radio frequency link, the AP measures the radio frequency signal to obtain the uplink equivalent channel matrix, adjusts the uplink equivalent channel matrix according to the phase compensation value of each radio frequency link, and calculates the adjusted uplink equivalent channel matrix. After the uplink equivalent channel matrix is transposed, the downlink equivalent channel matrix is obtained, and the accuracy of the downlink equivalent channel matrix is improved.

In an optional implementation manner, the phase compensation value of the single device is a function of a variable, and the variable includes the frequency point of the working channel and the receiving gear of the corresponding gain device.

Based on the above technical solution, the AP determines the single-device phase compensation value of the gain device according to the frequency point of the working channel and the receiving gear, so as to improve the accuracy of the single-device phase compensation value of the gain device, thereby improving the accuracy of the phase compensation value of the radio frequency link. degree, which is equivalent to improving the accuracy of the AP's determination of the downlink equivalent channel matrix.

In an optional implementation manner, the variable further includes temperature.

Based on the above technical solution, the influence of different temperatures on the phase compensation value of a single device of the gain device is considered, that is, the AP determines the phase compensation value of the single device of the gain device according to the temperature, the frequency point of the working channel, and the receiving gear to further improve the gain device. The accuracy of the single-device phase compensation value.

In an optional implementation manner, the gain device includes an external low-noise amplifier, an internal low-noise amplifier or a variable gain amplifier.

In an optional implementation manner, each phase compensation value in the plurality of phase compensation values is determined based on the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency chain, including:

Each phase compensation value in the plurality of phase compensation values is obtained by adding the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency link and the sub-carriers to which the uplink equivalent channel matrix belongs. adjustment value.

Based on the above technical solutions, the AP measures the radio frequency signal to obtain the uplink equivalent channel matrix corresponding to each subcarrier; the AP determines the phase adjustment value of each subcarrier according to the subcarrier to which each uplink equivalent channel matrix belongs; The sum of the respective single-device phase compensation values of the two gain devices is added to the phase adjustment value of each subcarrier to obtain the phase adjustment value of each subcarrier. The phase adjustment value of each subcarrier is used to adjust the uplink equivalent channel matrix of the corresponding subcarrier, so as to further improve the accuracy of the AP's determination of the downlink equivalent channel matrix.

In a second aspect, the present application provides a phase calibration method, the method comprising:

The AP uses the first radio frequency link in the first state to process the first radio frequency signal transmitted by the second radio frequency link to obtain the first baseband signal, wherein the first radio frequency link includes at least two gain devices, so The at least two gain devices include a first gain device, the receiving gear of the first gain device in the first radio frequency link in the first state is in the gear to be measured, and the first gain device is in the gear to be measured, and the first gain device is in the first state. The receiving gears of the gain devices other than the gain devices are in their respective preset gears;

The AP determines, according to the first baseband signal and the second baseband signal, the single-device phase compensation value when the first gain device is in the gear to be measured; the second baseband signal is used by the AP in the second The first radio frequency link in the state is obtained by processing the second radio frequency signal transmitted by the second radio frequency link, wherein the receiving files of all gain devices in the first radio frequency link in the second state are The first radio frequency signal and the second radio frequency signal have the same initial phase.

Based on the above technical solution, the AP determines, according to the first baseband signal and the second baseband signal, that the gain device is in the gear to be measured compared with the phase jump caused by the gain device being in the preset gear, and then determines that the gain device is in the gear to be measured. Single device phase compensation value in gear. The single-device phase compensation value can be used to adjust the uplink equivalent channel matrix, thereby predicting the downlink equivalent channel matrix with higher accuracy.

In an optional implementation manner, the single-device phase compensation value when the first gain device is in the gear to be measured is based on the phase of the first baseband signal and the phase of the second baseband signal. Poorly determined.

Based on the above technical solution, the AP determines the single-device phase compensation value when the first gain device is in the gear to be measured according to the phase difference between the phase of the first baseband signal and the phase of the second baseband signal, that is, determines that the first gain device is in The phase jump generated when the preset gear and the gear to be tested are used, so that the single-device phase compensation value is applied to adjust the uplink equivalent channel matrix.

In an optional implementation manner, the first radio frequency signal or the second radio frequency signal includes multiple identical long train fields (long train fields, LTF).

Based on the above technical solutions, the AP performs multi-symbol superposition based on multiple identical LTFs to improve the signal-to-noise ratio.

In a third aspect, the present application provides an AP, including:

communication unit and processing unit;

the communication unit, configured to receive radio frequency signals from the STA through multiple radio frequency links, each of the multiple radio frequency links includes at least two gain devices;

The processing unit is configured to measure the radio frequency signal and obtain a downlink equivalent channel matrix of the channel from the AP to the STA according to multiple phase compensation values, where the downlink equivalent channel matrix is the STA Transpose of the uplink equivalent channel matrix of the channel to the AP, the relationship between the plurality of phase compensation values and the plurality of radio frequency links is one-to-one correspondence, and the uplink equivalent channel matrix includes a plurality of row vectors , the relationship between the plurality of row vectors and the plurality of radio frequency links is one-to-one correspondence, and each row vector of the uplink equivalent channel matrix is adjusted by the phase compensation value of the corresponding radio frequency link. Each of the phase compensation values is determined based on the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency chain.

In an optional implementation manner, the phase compensation value of the single device is a function of a variable, and the variable includes the frequency point of the working channel and the receiving gear of the corresponding gain device.

In an optional implementation manner, the variable further includes temperature.

In an optional implementation manner, the gain device includes an external low-noise amplifier, an internal low-noise amplifier or a variable gain amplifier.

In an optional implementation manner, each phase compensation value in the plurality of phase compensation values is the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency The adjustment value obtained by the subcarrier to which the effective channel matrix belongs.

In a fourth aspect, the present application provides an AP, including:

communication unit and processing unit;

the communication unit, configured to transmit a first radio frequency signal using a second radio frequency link; and receive the first radio frequency signal using the first radio frequency link;

The processing unit is configured to process the first radio frequency signal by using the first radio frequency link in the first state to obtain a first baseband signal, wherein the first radio frequency link includes at least two gain devices, The at least two gain devices include a first gain device, and the receiving gear of the first gain device in the first radio frequency link in the first state is in the gear to be measured, and except for the first gain device. The receiving gears of gain devices other than a gain device are in their respective preset gears;

The processing unit is further configured to determine, according to the first baseband signal and the second baseband signal, a single device phase compensation value when the first gain device is in the gear to be measured; the second baseband signal is the The processing unit is obtained by processing the second radio frequency signal transmitted by the second radio frequency link with the first radio frequency link in the second state, wherein the first radio frequency link in the second state is in the second state. The receiving gears of all gain devices are in their respective preset gears; the initial phases of the first radio frequency signal and the second radio frequency signal are the same.

In an optional implementation manner, the single-device phase compensation value when the first gain device is in the gear to be measured is based on the phase difference between the phase of the first baseband signal and the phase of the second baseband signal. definite.

In an optional implementation manner, the first radio frequency signal or the second radio frequency signal includes multiple identical LTFs.

In a fifth aspect, the present application provides an AP, including:

processor, multiple RF links;

The multiple radio frequency links are used to receive radio frequency signals from the STA, and each radio frequency link in the multiple radio frequency links includes at least two gain devices;

The processor is configured to measure the radio frequency signal and obtain a downlink equivalent channel matrix of the channel from the AP to the STA according to multiple phase compensation values, where the downlink equivalent channel matrix is the STA Transpose of the uplink equivalent channel matrix of the channel to the AP, the relationship between the plurality of phase compensation values and the plurality of radio frequency links is one-to-one correspondence, and the uplink equivalent channel matrix includes a plurality of row vectors , the relationship between the plurality of row vectors and the plurality of radio frequency links is one-to-one correspondence, and each row vector of the uplink equivalent channel matrix is adjusted by the phase compensation value of the corresponding radio frequency link. Each of the phase compensation values is determined based on the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency chain.

In an optional implementation manner, the phase compensation value of the single device is a function of a variable, and the variable includes the frequency point of the working channel and the receiving gear of the corresponding gain device.

In an optional implementation manner, the variable further includes temperature.

In an optional implementation manner, the gain device includes an external low-noise amplifier, an internal low-noise amplifier or a variable gain amplifier.

In an optional implementation manner, each phase compensation value in the plurality of phase compensation values is the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency The adjustment value obtained by the subcarrier to which the effective channel matrix belongs.

In a sixth aspect, the present application provides an AP, including:

a processor, a first radio frequency link, and a second radio frequency link;

the second radio frequency link for transmitting the first radio frequency signal;

the first radio frequency link is in a first state, and the first radio frequency link in the first state is configured to receive the first radio frequency signal and process the first radio frequency signal to obtain a first baseband signal; the The first radio frequency link includes at least two gain devices, the at least two gain devices include a first gain device, and the reception of the first gain device in the first radio frequency chain in the first state The gear is in the gear to be tested, and the receiving gears of the gain devices other than the first gain device are in their respective preset gears;

The processor is configured to determine, according to the first baseband signal and the second baseband signal, a single device phase compensation value when the first gain device is in the gear to be measured; the second baseband signal is in the second The first radio frequency link in the state is obtained by processing the second radio frequency signal transmitted by the second radio frequency link, wherein the receiving files of all gain devices in the first radio frequency link in the second state are obtained The first radio frequency signal and the second radio frequency signal have the same initial phase.

In an optional implementation manner, the single-device phase compensation value when the first gain device is in the gear to be measured is based on the phase difference between the phase of the first baseband signal and the phase of the second baseband signal. definite.

In an optional implementation manner, the first radio frequency signal or the second radio frequency signal includes multiple identical LTFs.

In a seventh aspect, the present application provides a computer-readable storage medium, in which a computer program or instruction is stored, and when the computer program or instruction is executed, the method described in the first aspect or the second aspect is executed. accomplish.

In an eighth aspect, the present application provides a computer program product, the computer program product comprising a computer program or an instruction, when the computer program or the instruction is executed, the method described in the first aspect or the second aspect is implemented.

For the technical effects that can be achieved in any one of the third aspect to the eighth aspect, reference may be made to the description of the beneficial effects in the first aspect or the second aspect, which will not be repeated here.

Description of drawings

FIG. 1 is a system schematic diagram of a WLAN deployment scenario provided by an embodiment of the present application;

FIG. 2 is a schematic diagram of interaction between an AP and a STA according to an embodiment of the present application;

3 is a schematic structural diagram of a radio frequency link in an AP according to an embodiment of the present application;

4 is a schematic diagram of reciprocity calibration performed by an AP according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a process flow of a phase calibration method provided by an embodiment of the present application;

FIG. 6 provides a schematic diagram of a phase compensation table according to an embodiment of the present application;

FIG. 7 provides a schematic diagram of a format of a calibration signal according to an embodiment of the present application;

8 provides a schematic diagram of a correspondence between a phase compensation table and a frequency point according to an embodiment of the present application;

FIG. 9 provides a schematic diagram of the correspondence between a phase compensation table, a frequency point and a temperature according to an embodiment of the present application;

10 is a schematic diagram of a process flow of a phase compensation method provided by an embodiment of the present application;

11 provides a schematic diagram of device gear positions of each gain device corresponding to a link gear position according to an embodiment of the present application;

12 provides a schematic diagram of a process for an AP to determine a downlink equivalent channel matrix according to an embodiment of the present application;

FIG. 13 provides a schematic structural diagram of a first AP according to an embodiment of the present application;

FIG. 14 provides a schematic structural diagram of a second AP according to an embodiment of the present application;

FIG. 15 is a schematic structural diagram of a third AP according to an embodiment of the present application.

Detailed ways

The embodiments of the present application may be applied to a WLAN, and the standard adopted by the WLAN is the IEEE 802.11 series. A WLAN may include one or more basic service sets (BSSs), and network nodes in the basic service sets include APs and STAs. Each basic service set may contain one AP and multiple STAs associated with the AP. The AP can be used to communicate with the STA through the wireless local area network, and transmit the data of the STA to the network side, or transmit the data from the network side to the STA.

AP, also known as hotspot. APs are access points for mobile users to access wired networks. They are mainly deployed in homes, buildings, and campuses, with a typical coverage radius ranging from tens of meters to hundreds of meters. Of course, they can also be deployed outdoors. The AP can be a terminal device or a network device with a WLAN chip.

The STA may be a wireless communication chip, a wireless sensor or a wireless communication terminal. For example: mobile phone supporting WLAN communication function, tablet computer supporting WLAN communication function, set-top box supporting WLAN communication function, smart TV supporting WLAN communication function, smart wearable device supporting WLAN communication function, in-vehicle communication supporting WLAN communication function devices and computers that support WLAN communication.

The system architecture and application scenarios described in this application are for the purpose of illustrating the technical solutions of this application more clearly, and do not constitute a limitation on the technical solutions provided in this application. When a scenario occurs, the technical solutions provided in this application are also applicable to similar technical problems.

FIG. 1 is a system schematic diagram of a WLAN deployment scenario. FIG. 1 includes one AP and three STAs. The AP communicates with STA1 , STA2 and STA3 respectively to form a BSS. Devices in the same BSS share the air interface channel, and only one device can send data in the air interface channel at a time. Before STA1, STA2 and STA3 send data, they need to monitor the air interface channel and compete for the air interface channel when the channel is idle.

With reference to the schematic diagram shown in FIG. 1 , the process of the AP sending a signal to the STA through the IBF is described as follows. The STA may be any one of STA1, STA2 and STA3 as shown in FIG. 1 .

Figure 2 is a schematic diagram of an AP sending a signal to a STA through an IBF. Referring to Figure 2, the AP receives the radio frequency signal from the STA through multiple radio frequency links, and the AP performs channel estimation on the uplink channel according to the radio frequency signal to obtain the STA The channel state information (channel state information, CSI) of the channel to the AP is understood to mean that the AP performs channel estimation on the uplink channel according to the radio frequency signal, so as to obtain the uplink equivalent channel matrix. The AP determines the transposed matrix of the uplink equivalent channel matrix as the downlink equivalent channel matrix of the channel from the AP to the STA. The AP generates a precoding matrix according to the downlink equivalent channel matrix, performs BF weighting on the original baseband signal according to the precoding matrix, and determines the baseband signal of each radio frequency link. RF signal is sent to the STA. Here, the uplink equivalent channel matrix may also be referred to as an uplink channel matrix and a channel matrix from STA to AP; the downlink equivalent channel matrix may also be referred to as a downlink channel matrix and a channel matrix from AP to STA.

Further, the radio frequency signal includes an LTF field, for example, a traditional long training field (legacy-long trainfield, L-LTF), an extremely high throughput-long train field (EHT-LTF), a very high throughput Throughput long training field (very high throughput-long train field, VHT-LTF), high efficiency long training field (high efficiency-long train field, HE-LTF) and so on. The LTF field is used by the AP to perform channel estimation on the uplink channel.

It should be noted that there is a radio frequency link in both the AP and the STA. When the gain device in the radio frequency link amplifies the signal, the phase jump of the signal occurs.

Taking the AP side as an example, FIG. 3 is a schematic structural diagram of a radio frequency link in an AP provided by an embodiment of the application. As shown in FIG. 3 , the AP includes four radio frequency links, which are radio frequency links from top to bottom. 0. RF link 1, RF link 2, and RF link 3. The structure of each RF link is the same, and each RF link includes three-stage gain devices, which are an external low noise amplifier (external low noise amplifier, eLNA), an internal low noise amplifier (internal low noise amplifier, iLNA) and a variable gain amplifier ( variable gain amplifier, VGA).

The three-stage gain devices are respectively used to amplify the signal gain. Among them, the eLNA is the first-stage low noise amplifier, which has the characteristics of large gain step and good noise factor (NF). For example, when the eLNA is turned on, it is about 10dB. to 12dB of positive gain, about 10dB of negative gain when turned off. The iLNA is the second-level low noise amplifier. For example, the iLNA can be divided into 8 gears, and the difference between each pair is about 6dB. VGA is the third-stage variable gain amplifier, which has the characteristics of analog signal down-conversion and post-amplification, and high precision of adjustable gain. Usually, its gain step can reach 1dB.

In the above three-stage gain device, each gain device can have different degrees of phase influence on the signal. Specifically, when the analog signal passes through each gain device, the initial phase jump caused by the radio frequency delay to the signal and the phase jump on each sub-carrier are generated. For example, before up-conversion, the RF delay of the eLNA and iLNA will cause the initial phase hopping of the signal and the phase hopping on each sub-carrier, while the IF delay of the down-converted VGA will cause the signal to jump in each sub-carrier. Phase hopping on subcarriers.

Take the k-th subcarrier signal _sk (t) as an example, where _sk (t)=a(k)e ^j2πkΔft . Assuming that the amplitude response is 1, after the signal _sk (t) passes through the eLNA, iLNA and VGA, the output _sk (t)' is shown in equation (1).

In formula (1), τ _RF is the radio frequency delay, including the delay generated by the corresponding eLNA and iLNA; τ _IF is the intermediate frequency delay, including the delay generated by the corresponding VGA.

For ease of understanding, the following takes the zero-IF circuit as an example, where τ _IF in formula (1) is 0, and formula (2) is obtained.

指示射频时延导致信号的初始相位跳变；

指示射频时延导致信号的子载波上的相位跳变。in,

Indicates that the RF delay causes the initial phase jump of the signal;

Indicates that the RF delay causes a phase jump on the sub-carriers of the signal.

Further, in the zero-IF circuit, the input radio frequency signal y(t) is shown in formula (3).

Wherein, x(t)=x _I (t)+jx _Q (t) is the baseband signal, which is Fourier-expanded x(t)=∑ _k a _k e ^j2πkΔft .

The output radio frequency signal y(t)' is shown in formula (4).

in,

指示射频时延导致信号的初始相位跳变；

指示射频时延导致信号在各子载波上的相位跳变。

Indicates that the RF delay causes the initial phase jump of the signal;

Indicates that the RF delay causes the phase jump of the signal on each subcarrier.

To sum up, when each gain device in the RF link processes the signal, the RF delay will affect the initial phase of the signal and the phase on each sub-carrier, thereby affecting the accuracy of the signal.

Further, since the phase effect of the radio frequency link on the signal when the AP transmits the signal is different from the phase effect of the radio frequency link on the signal when the AP receives the signal, the uplink channel and the downlink channel between the AP and the STA are not completely equivalent. .

In order to realize the equivalence of uplink channel and downlink channel between AP and STA, a reciprocity calibration method is proposed. Since the phase effect of the radio frequency link used to receive the signal on the STA side can be canceled by the equalization on the STA side, the reciprocity calibration method is mainly implemented on the AP side.

The reciprocity calibration method can be implemented by the AP spontaneously sending and receiving a calibration signal, and the calibration signal is understood as a radio frequency signal used for reciprocity calibration. FIG. 4 is a schematic diagram of reciprocity calibration performed by an AP provided by the present application. For a schematic structural diagram of a radio frequency link in an AP, reference may be made to FIG. 3 , which will not be repeated.

Taking the reciprocity calibration performed by the AP on RF link 0 as an example, in Figure 4(a), RF link 0 sends RF signals to RF link 1, RF link 2, and RF link 3, respectively, to obtain the RF link Channel 0 is used as the calibration result of the transmitting RF link. In Figure 4(b), RF link 0 receives the RF signals from RF link 1, RF link 2, and RF link 3 respectively, and obtains RF link 0 as After receiving the calibration result of the radio link, the AP determines the reciprocity compensation value of radio link 0 based on the two calibration results.

In this way, the AP can determine the reciprocity compensation value corresponding to each radio frequency link in the AP based on the reciprocity calibration, and then the AP performs mutual reciprocity compensation for the baseband signals in each radio frequency link based on the reciprocity compensation value corresponding to each radio frequency link. Transmit to STA after changeability compensation.

However, during the above reciprocity calibration, the AP sets the radio link in the fixed link gear to receive and process radio signals. In practical applications, because each STA needs to compete for air interface channels, the signal power of the RF signal received by the AP may change. to the RF signal processing. When the AP performs reciprocity calibration, the fixed link range used by each radio link is different from the link range used by each radio link when the AP actually receives signals.

Referring to FIG. 1 and FIG. 4 , each radio frequency link of the AP has 4 link positions, namely link position A, link position B, link position C, and link position D. When the AP performs reciprocity calibration on RF link 0, the AP determines that RF link 0 is in fixed link position A to process RF signals from RF link 1, RF link 2, and RF link 3; while the actual application , when the AP receives the RF signal 1 from STA1, it automatically adjusts the RF link 0 to link position B according to the signal power of the RF signal 1, or, when the AP receives the RF signal 2 from STA2, it automatically adjusts the RF link The signal power of 2 automatically adjusts the RF link 0 to link position C.

Similar to other RF links, when the AP performs reciprocity calibration on RF link 1, the AP determines that RF link 1 is in fixed link position B to process the signals from RF link 0, RF link 2, and RF link 3. In practical applications, when the AP receives the RF signal 1 from STA1, it automatically adjusts the RF link 1 to link position A according to the signal power of the RF signal 1, or the AP is receiving the RF signal from STA2. 2, the radio frequency link 1 is automatically adjusted to the link gear C according to the signal power of the radio frequency signal 2.

In addition, because each RF link has different phase effects on the signal when it is in different link gears, the fixed link gear used by each RF link when the AP performs reciprocity calibration and each RF link when the AP actually receives the signal. Different link gears used by the link will cause the signal to jump in phase. In this case, when the AP performs reciprocity compensation based on the reciprocity compensation value, the problem of inaccurate compensation will occur, which further leads to the inequivalence of the uplink channel and the downlink channel, which affects the accuracy of the signals transmitted by the AP's radio frequency links. .

Based on the above problem, a phase calibration method provided by the embodiments of the present application can be performed in the AP, or in a module (eg, a chip) applied to the AP. The AP and the STA are used as examples for description below.

Referring to the flowchart shown in FIG. 5 , the phase calibration method provided by the embodiment of the present application is described as follows.

For the convenience of description, the AP determines the phase compensation value of the single device when the first gain device in the first radio frequency link is in the gear to be tested as an example for description. The first radio frequency link is any one of multiple radio frequency links of the AP, the first radio frequency link includes at least two gain devices, and the first gain device is any one of the at least two gain devices.

Step 501, the AP processes the first radio frequency signal transmitted by the second radio frequency link with the first radio frequency link in the first state to obtain the first baseband signal.

The AP can perform phase calibration in a self-transmitting and self-receiving manner. The AP includes a first radio frequency link and a second radio frequency link. The AP transmits the first radio frequency signal through the second radio frequency link, and the AP receives the first radio frequency signal through the first radio frequency link. Radio frequency signals, that is, the second radio frequency link is a radio frequency link for transmitting signals, and the first radio frequency link is a radio frequency link for receiving signals.

Further, the AP can preempt the air interface channel of the second radio frequency link to the first radio frequency signal, and then send the first radio frequency signal to the first radio frequency link through the air interface channel through the second radio frequency link; the AP can also use the second radio frequency The link sends the first radio frequency signal to the first radio frequency link via internal circuitry.

The AP may set the first radio frequency link to be in a first state, wherein the receiving gear of the first gain device in the first radio frequency link in the first state is in the gear to be tested, and the gain of the first gain device other than the first gain device The receiving gears of the devices are all in their respective preset gears. For example, the gain devices in the first RF link are eLNA, iLNA, and VGA in sequence, and the preset gears corresponding to eLNA, iLNA, and VGA are set to eLNA gear 0, iLNA gear 1, and VGA gear 1, respectively. Wherein, the iLNA is the first gain device, and the gear position of the iLNA to be tested is the iLNA gear position 2 . Fix the eLNA, iLNA, and VGA gears to eLNA gear 0, iLNA gear 2, and VGA gear 1, respectively.

In practical applications, when the AP receives the first radio frequency signal through the first radio frequency link, it needs to automatically adjust the link level of the first radio frequency link according to the signal power of the first radio frequency signal, that is, automatically adjust the first radio frequency link. The device gear of each gain device in . Therefore, when the AP performs phase calibration, automatic gain control (automatic gain control, AGC) may be used to control each gain device in the first radio frequency chain to be in a fixed device position to process the first radio frequency signal.

Step 502, the AP determines, according to the first baseband signal and the second baseband signal, a single-device phase compensation value when the first gain device is in the gear to be measured.

The second baseband signal is obtained by the AP processing the second radio frequency signal transmitted by the second radio frequency link of the AP through the first radio frequency link in the second state, wherein the first radio frequency link in the second state is in the second state. The receiving gears of all gain devices are in their respective preset gears; and the initial phases of the first radio frequency signal and the second radio frequency signal are the same.

It is understood that the AP generates the same original baseband signal twice, the first time the original baseband signal is output as the first radio frequency signal through the second radio frequency link, and the first radio frequency signal is processed through the first radio frequency link in the first state to obtain the first radio frequency signal. a baseband signal; the second original baseband signal is output as a second radio frequency signal through the second radio frequency link, and the second radio frequency signal is processed by the first radio frequency link in the second state to obtain the second baseband signal; wherein, in the first radio frequency link The only difference between the first radio frequency link in the state and the first radio frequency link in the second state is that the first gain device of the former is in the gear to be tested, and the first gain device of the latter is in the preset gear. bit. The AP determines, according to the first baseband signal and the second baseband signal, a single-device phase compensation value when the first gain device is in the gear to be measured.

The AP determines, according to the first baseband signal and the second baseband signal, the phase compensation value of the single device when the first gain device is in the gear to be measured. There are at least two implementations as follows.

Implementation mode 1: The AP determines the single-device phase compensation value when the first gain device is in the gear to be measured according to the phase difference between the phase of the first baseband signal and the phase of the second baseband signal.

Implementation mode 2. The AP determines the first phase difference caused by the first radio frequency link processing the radio frequency signal when the first gain device is in the gear to be tested according to the phase of the first baseband signal and the phase of the original baseband signal; the AP determines the first phase difference according to the first phase The difference between the difference and the preset phase difference determines the single-device phase compensation value when the first gain device is in the gear to be measured. The preset phase difference is a phase difference caused by the first radio frequency link processing the radio frequency signal when the first gain device is in the preset gear according to the phase of the second baseband signal and the phase of the original baseband signal.

Further, the first gain device may include multiple device gears, that is, the AP may perform multiple phase calibrations on the first gain device. For example, the first gain device includes 8 device gears, where the device gear 0 is With the preset gear, the AP can perform 7 phase calibrations for the first gain device. In order to improve the phase calibration efficiency, the AP can use the second baseband signal obtained when the first gain device is in device gear 0 (the first radio frequency link is in the second state) to be used for the first gain device in device gears 1 to 1, respectively. During any phase calibration of device gear 7 (the first RF link is in the first state).

In the above implementation mode 1, the AP stores the phase of the second baseband signal in the storage module of the AP in advance, so that the AP can determine the first gain device according to the phase of the first baseband signal and the pre-stored phase of the second baseband signal Single device phase compensation value when in each device gear. In the above-mentioned implementation mode 2, the AP pre-stores the preset phase difference in the storage module of the AP, so that the AP can determine that the first gain device is in the Single device phase compensation value for each device gear.

After the AP determines the single-device phase compensation value when the first gain device is in the gear to be measured, the single-device phase compensation value may be recorded in the phase compensation table. The phase compensation table records the single-device phase compensation values when each gain device in the radio frequency chain is in its own device gear.

Exemplarily, the gain devices in the radio frequency chain include eLNA, iLNA, and VGA, wherein the eLNA has 2 eLNA gears, the iLNA has 8 iLNA gears, and the VGA has 32 VGA gears. The preset gears are eLNA gear 0, iLNA gear 0 and VGA gear 0 respectively.

The AP determines the single-device phase compensation value when the eLNA is in eLNA gear 1; the single-device phase compensation value when the iLNA is in iLNA gear 1, ..., iLNA gear 6, and iLNA gear 7 respectively; VGA is in VGA gear respectively 1. The phase compensation value of a single device when the VGA gear is 30 and the VGA gear is 31; the phase compensation table shown in Figure 6 is finally obtained. It should be noted that when the AP determines the single-device phase compensation value of the gain device, the AP uses the preset gear position of the gain device as the benchmark to determine the phase jump generated by the gain device in each device gear position. The phase difference between the phase jumps produced when the gear is preset. It should be understood that the AP does not need to determine the single-device phase compensation value when the gain device is in the preset gear, but it can also be understood that the AP determines the single-device phase compensation value of the gain device at the preset gear to be 0.

As shown in Figure 6, the AP determines that the single-device phase compensation value is 0 when the eLNA is in the eLNA gear 0; the AP determines that the single-device phase compensation value is 0 when the iLNA is in the iLNA gear 0; AP determines that the VGA is in the VGA gear 0. The single-device phase compensation value of 0 is 0.

6 , when the AP determines the single-device phase compensation value for each gain device when it is in each device gear (including the AP's determination of the single-device phase compensation value when each gain device is in its respective preset gear), the AP determines The eLNA performs 2 phase calibrations, the AP performs 8 phase calibrations for the iLNA, and the AP performs 32 phase calibrations for the VGA, so the AP performs a total of 42 phase calibrations and generates 42 single-device phase compensation values. However, if the AP determines the link phase compensation value for each radio link when it is in each link gear, since the radio link has a total of 512 (2×8×32=512) link gears, the AP needs to 512 phase calibrations are performed and 512 phase compensation values for the radio frequency chain are generated.

It can be seen that in the above phase calibration method, the AP determines the single-device phase compensation value for each gain device when it is in each device gear, and the generated phase compensation table is also for each device gear of each gain device. This method can reduce the computational complexity of the AP and the storage size of the phase compensation table in the AP.

The first radio frequency signal and the second radio frequency signal may be understood as calibration signals in the phase calibration performed by the AP. FIG. 7 exemplarily shows the format of a calibration signal provided by the present application. The calibration signal includes a WLAN legacy field (Legacy field) and multiple identical LTFs, wherein the WLAN legacy field is an HE SU frame format, and each The LTF is generated by using an LTF with a better peak to average power ratio (PAPR), and is the same orthogonal frequency division multiplexing (OFDM) symbol in the time domain. In this way, the AP performs multi-symbol superposition based on multiple identical LTFs to improve the signal-to-noise ratio.

It should be noted that, since multiple RF links in the AP are products of the same batch, that is, the gain devices of the same type in each RF link are products of the same batch, the gain devices of the same type in different RF links are in different locations. The corresponding single-device phase compensation values in the device gears are almost the same. Therefore, in order to improve the phase calibration efficiency, it is possible to determine the single device of each gain device in the RF link when it is in each device gear for any RF link. phase compensation value and use it in other RF chains.

For example, in Figure 3, the AP includes four radio frequency links, and each radio frequency link includes three gain devices: eLNA, iLNA, and VGA. The single-device phase compensation value of the iLNA in each iLNA gear and the single-device phase compensation value of the VGA when the VGA is in each VGA gear, and apply these single-device phase compensation values to RF link 1, RF link 2, and RF link Road 3.

With reference to the schematic structural diagram of the radio frequency link in the AP shown in FIG. 3 , an implementation manner for determining the phase compensation value of a single device is provided below.

The first radio frequency link may be any one of the four radio frequency links, and the second radio frequency link may be another radio frequency link except the first radio frequency link among the four radio frequency links. The gain devices in the first radio frequency chain include eLNA, iLNA, and VGA, wherein the eLNA has 2 eLNA gears, the iLNA has 8 iLNA gears, and the VGA has 32 VGA gears.

It is illustrated by taking the first gain device as an iLNA as an example.

Assume that the default gears of eLNA, iLNA and VGA are eLNA gear 0, iLNA gear 0 and VGA gear 0 respectively. As follows, determine the single-device phase compensation value when the iLNA is in each iLNA gear.

The AP broadcasts a control signal (for example, CTS to SELF), and the control signal is used to preempt an air interface channel, so that the AP can send the first radio frequency signal or the second radio frequency signal to the first radio frequency link through the second radio frequency link.

The AP sets the first radio frequency link to be in the second state, that is, sets the eLNA, iLNA, and VGA to be in eLNA gear 0, iLNA gear 0, and VGA gear 0, respectively. The AP generates the original baseband signal, outputs the original baseband signal as the second radio frequency signal through the second radio frequency link, the AP transmits the second radio frequency signal to the first radio frequency link through the air interface channel, and the first radio frequency link processes the second radio frequency The signal results in a second baseband signal.

The AP determines the single-device phase compensation value when the iLNA is in iLNA gear 1. Specifically, the AP sets the first radio frequency link to be in the first state, that is, sets the eLNA, iLNA, and VGA to be in eLNA gear 0, iLNA gear 1, and VGA gear 0, respectively. The AP generates the original baseband signal, outputs the original baseband signal as the first radio frequency signal through the second radio frequency link, the AP transmits the first radio frequency signal to the first radio frequency link through the air interface channel, and the first radio frequency link processes the first radio frequency The signal obtains a first baseband signal. The AP determines a single-device phase compensation value (iLNA single-device phase compensation value 1) when the iLNA is in iLNA gear 1 according to the phase of the first baseband signal and the phase of the second baseband signal.

The AP determines the single-device phase compensation value when the iLNA is in iLNA gear 2. Specifically, the AP sets the first radio link to be in the first state, that is, sets the eLNA, iLNA, and VGA to be in eLNA gear 0, iLNA gear 2, and VGA gear 0, respectively. The AP generates the original baseband signal, the original baseband signal is output as the first radio frequency signal through the second radio frequency link, the AP transmits the first radio frequency signal to the first radio frequency link through the air interface channel, and the first radio frequency link processes the first radio frequency signal A first baseband signal is obtained. The AP determines a single-device phase compensation value (iLNA single-device phase compensation value 2) when the iLNA is in iLNA gear 2 according to the phase of the first baseband signal and the phase of the second baseband signal.

The single-device phase compensation value determined by the AP when the iLNA is in iLNA gear 3 to iLNA gear 7 is similar to the single-device phase compensation value determined by the AP when the iLNA is in iLNA gear 1 or iLNA gear 2, and will not be repeated.

In addition, when the first gain device is an eLNA, the AP determines the single-device phase compensation value when the eLNA is in each eLNA gear, which is similar to the single-device phase compensation value determined by the AP when the iLNA is in each iLNA gear; the first gain device is In the case of VGA, the AP determines the single-device phase compensation value when the VGA is in each VGA gear, which is similar to the single-device phase compensation value determined by the AP when the iLNA is in each iLNA gear;

As above, the phase compensation table shown in FIG. 6 can be obtained.

In the embodiment of the present application, the preset gear of each gain device may be determined according to the fixed link gear during AP reciprocity calibration. For example, in Figure 4, the fixed link gear during AP reciprocity calibration is link gear A, then the eLNA gear 0, iLNA gear 1 and VGA gear 1 corresponding to link gear A are respectively determined as Default gears for eLNA, iLNA and VGA.

It should be noted that when the AP performs reciprocity calibration in different environments, the fixed link gear used by the AP may be different. For example, in environment 1, the AP uses link gear A as the fixed link gear, while In environment 2, the AP adopts link gear C as the fixed link gear. Therefore, the fixed link gear during AP reciprocity calibration can be temporarily ignored, and the preset gears of each gain device in the AP can be determined according to the actual situation. For example, eLNA gear 0 and iLNA gear 0 are directly and VGA gear 0 are determined as the preset gears of eLNA, iLNA and VGA respectively.

Here, it should be understood that the AP has two setting methods. Setting method 1 is to determine the preset gear of each gain device according to the fixed link gear during AP reciprocity calibration, and setting method 2 is to determine according to the actual situation. Preset gears of each gain device. Since the preset gears of the gain devices set by the two are different, the single-device phase compensation values of the gain devices determined by the two are also different. Therefore, there are differences in the compensation manners when the APs perform phase compensation, and for the differences, refer to the following embodiments of the APs performing phase compensation.

It can be seen from the above embodiments that the single-device phase compensation value of the gain device in different device gears is different, which is equivalent to that the single-device phase compensation value of the gain device is a function of the device gear of the gain device. Further, in order to improve the accuracy of the single-device phase compensation value of the gain device in different device gears, the embodiment of the present application considers the influence of the working channel frequency of the gain device on the single-device phase compensation value of the gain device, that is, In an optional implementation manner, the device gear position of the gain device and the frequency point of the working channel are used as variables, and the single-device phase compensation value of the gain device is a function of the variables.

The AP sets a corresponding phase compensation table for each frequency point. That is to say, when the AP performs phase calibration, for the specific frequency point of the working channel, it determines the phase compensation value of each gain device in each device gear in the RF link, and records the obtained phase compensation value of the single device. In the phase compensation table corresponding to a specific frequency point. The AP can statically store multiple phase compensation tables.

Exemplarily, the correspondence between the phase compensation table and the frequency points stored in the AP may be as shown in FIG. 8 . The frequency point is used to indicate a frequency band, for example, the frequency point f _c1 is used to indicate the frequency band (f _c1 -Δf ₁ , f _c1 +Δf ₁ ), wherein the frequency point f _c1 is the frequency band (f _c1 -Δf ₁ , f _c1 + Δf ₁ ) center frequency. The value of each frequency point can be determined according to experience, which is not limited here.

Further, the above-mentioned variable that affects the phase compensation value of the single device in the AP may also include temperature, that is, the temperature of the environment where the AP is located. In another optional implementation manner, the device gear position of the gain device, the frequency point of the working channel, and the temperature are used as variables, and the single-device phase compensation value of the gain device is a function of the variables.

The AP sets the corresponding phase compensation table for each frequency point and each temperature. That is to say, when the AP performs phase calibration, according to the specific frequency point and specific temperature of the working channel, it determines the single-device phase compensation value of each gain device in the RF link in each device gear, and calculates the obtained single-device phase compensation value. The compensation value is recorded in the phase compensation table corresponding to a specific frequency point and a specific temperature. The AP can statically store multiple phase compensation tables.

The temperature is used to indicate a temperature interval, for example, the temperature T ₁ is used to indicate a temperature interval (T ₁ −ΔT ₁ , T ₁ +ΔT ₁ ). The frequency point is used to indicate a frequency band, for example, the frequency point f _c1 is used to indicate the frequency band (f _c1 -Δf ₁ , f _c1 +Δf ₁ ), wherein the frequency point f _c1 is the frequency band (f _c1 -Δf ₁ , f _c1 + Δf ₁ ) center frequency. The value of each frequency point and the value of each temperature can be determined according to experience, which is not limited here.

指示射频时延导致信号的初始相位跳变，也即，对信号在中心频点f_c的相位补偿值可以理解成信号的初始相位补偿值。In addition, it should be noted that in the phase compensation table corresponding to any frequency point or the phase compensation table corresponding to any frequency point and temperature, the single-device phase compensation value of the gain device in the device gear indicates that the gain device is in the device. The phase compensation value for the center frequency point on the gear. Assuming that the phase compensation table f _c1 -T ₁ is shown in FIG. 6 , the phase compensation value 1 of the eLNA single device in FIG. 6 is the phase compensation value of the eLNA at the eLNA gear 1 for the center frequency point f _c1 . Further, it can be seen from the above formula (4) that,

It indicates that the radio frequency delay causes the initial phase jump of the signal, that is, the phase compensation value of the signal at the center frequency point f _c can be understood as the initial phase compensation value of the signal.

Based on the above technical solution, the AP determines, according to the first baseband signal and the second baseband signal, that the gain device is in the gear to be measured compared with the phase jump caused by the gain device being in the preset gear, and then determines that the gain device is in the gear to be measured. Single device phase compensation value in gear. The single-device phase compensation value can be used to adjust the uplink equivalent channel matrix, so as to predict the downlink equivalent channel matrix with higher accuracy, and solve the problem of fixed link gear used in reciprocity calibration and automatic adjustment when receiving RF signals. The phase jump problem caused by the difference between the link gears.

The implementation of the phase calibration by the AP has been described in detail above. The AP can adjust the uplink equivalent channel matrix from the STA to the AP based on the single-device phase compensation value of each gain device obtained in the above phase calibration.

FIG. 10 is a schematic diagram of a flow of a phase compensation method provided by an embodiment of the present application, and the flow is as follows.

Step 1001, the AP receives radio frequency signals from the STA through multiple radio frequency links.

The AP includes multiple radio frequency links. When the AP receives the radio frequency signal from the STA through each radio frequency link, the AP adjusts each radio frequency link to the corresponding link gear according to the signal power of the radio frequency signal received by each radio frequency link. . The AP can adjust each radio frequency link to be in the same link gear to receive the radio frequency signal, or can adjust each radio frequency link to be in a different link gear to receive the radio frequency signal.

Each radio frequency chain includes at least two gain devices, and the link gear of each radio frequency chain corresponds to the receive gear of each gain device in the radio frequency chain. FIG. 11 exemplarily shows the device gear positions of each gain device corresponding to the link gear position. The gain devices in the radio frequency link include eLNA, iLNA and VGA. Exemplarily, link gear position A corresponds to eLNA gear position 0 and iLNA Gear 1 and VGA gear 1; link gear B corresponds to eLNA gear 1, iLNA gear 2, and VGA gear 4.

Step 1002, the AP measures the radio frequency signal and obtains the downlink equivalent channel matrix of the channel from the AP to the STA according to multiple phase compensation values.

Step 1002 may refer to the flowchart shown in FIG. 12 for details, and may include the following steps:

Step 1201, the AP measures the radio frequency signal to obtain the uplink equivalent channel matrix of the channel from the STA to the AP.

The uplink equivalent channel matrix of the channel from the STA to the AP includes multiple row vectors, the relationship between the multiple row vectors and the multiple radio frequency links is one-to-one correspondence, and each radio frequency link in the multiple radio frequency links corresponds to a phase Compensation value, the phase compensation value corresponding to each radio frequency chain is used to adjust the row vector corresponding to the radio frequency chain.

Step 1202, the AP determines the phase compensation value of each radio frequency link, and adjusts the row vector corresponding to each radio frequency link in the uplink equivalent channel matrix according to the phase compensation value of each radio frequency link.

Exemplarily, the AP receives radio frequency signals through N radio frequency links, and the AP measures the radio frequency signals to obtain the uplink equivalent channel matrix of the channel from the STA to the AP is H, and formula (5) can be referred to for H.

The AP determines that the phase compensation values of the N radio links are the phase compensation values 1, . The following H', H' can refer to formula (6).

In step 1202, when the AP determines the phase compensation value of each radio frequency chain, it may be determined according to the single device phase compensation value of each gain device in each radio frequency chain.

Taking any one of the RF links as an example, the AP determines the receiving gear of each gain device in the RF link, and determines from the phase compensation table that each gain device is in its own receiving gear according to the receiving gear of each gain device. The single-device phase compensation value at the time; the sum of the single-device phase compensation values of each gain device is determined as the phase compensation value of the radio frequency link.

Combining the above example in Figure 6, assuming Figure 6 is the phase compensation table of the AP, the single-device phase compensation value of the eLNA is the eLNA single-device phase compensation value of 1, the single-device phase compensation value of the iLNA is the iLNA single-device phase compensation value of 2, and the VGA The single-device phase compensation value is the VGA single-device phase compensation value of 4, and the phase compensation value of the RF link is determined to be the sum of the eLNA single-device phase compensation value of 1, the iLNA single-device phase compensation value of 2, and the VGA single-device phase compensation value of 4.

其中，

为增益器件在预设档位上的相位，

为增益器件在测试档位上的相位。上述例子中，比如，eLNA的单器件相位补偿值为

iLNA的单器件相位补偿值为

VGA的单器件相位补偿值为

则确定射频链路的相位补偿值

为

和

之和，

如公式(7)所示。In practical applications, the single-device phase compensation value can be expressed in the frequency domain as

in,

is the phase of the gain device at the preset gear,

is the phase of the gain device in the test gear. In the above example, for example, the single-device phase compensation value of the eLNA is

The single-device phase compensation value of the iLNA is

The single-device phase compensation value of VGA is

Then determine the phase compensation value of the RF link

for

and

Sum,

As shown in formula (7).

It should be noted that the single-device phase compensation value of the gain device in the above example may refer to the difference between the phase difference caused by the gain device in the preset gear and the phase difference caused by the receiving gear, that is, , when the AP determines the phase compensation value of a single device, it essentially uses the preset gear when the AP performs phase calibration as a reference.

When AP performs phase calibration, there are two preset gear setting methods (refer to the above setting method 1 and setting method 2). When AP performs phase compensation according to the phase compensation table obtained by different setting methods, the differences are as follows:

In setting mode 1, the preset gear is the device gear of each gain device corresponding to the fixed link gear during AP reciprocity calibration, and the AP can determine the gain device of each gain device in the RF link from the phase compensation table Single device phase compensation value, and then determine the phase compensation value of the RF link.

In setting mode 2, the preset gear is the device gear of each gain device determined according to actual experience. At this time, the preset gear of each gain device is not necessarily the same as the device gear during AP reciprocity calibration. Consistent, after the AP determines the single-device phase compensation value of each gain device in the RF link from the phase compensation table, it needs to adjust each gain according to the preset gear position of each gain device and the device gear position during AP reciprocity calibration The single-device phase compensation value of the device, which in turn determines the phase compensation value of the RF link.

In addition, it can be known from the above phase calibration process that the single-device phase compensation value of the gain device is affected by variables.

In an implementation manner, the variables include the working channel frequency and the receiving gear of the gain device; and multiple phase compensation tables are stored in the AP, and each phase compensation table corresponds to a specific frequency. Before the AP determines the single-device phase compensation value of each gain device in its respective receiving gear, it can obtain the phase compensation table corresponding to the working channel frequency of the gain device, and determine the phase compensation table corresponding to the working channel frequency from the phase compensation table. The single-device phase compensation value of each gain device in its respective receive gear.

8, when the working channel frequency of the AP is located in the frequency band (f _c1 -Δf ₁ , f _c1 +Δf ₁ ), the AP obtains the phase compensation table f _c1 ; when the working channel frequency of the AP is located in the frequency band (f c1 +Δf 1 ) _c2 −Δf ₂ , f _c2 +Δf ₂ ), the AP obtains the phase compensation table f _c2 .

In another implementation, the variables include the working channel frequency, temperature, and receiving gear of the gain device; and multiple phase compensation tables are stored in the AP, and each phase compensation table corresponds to a specific frequency point and a specific temperature. Before determining the phase compensation value of each gain device when each gain device is in its respective receiving gear, the AP can obtain the phase compensation table corresponding to the temperature of the gain device and the frequency of the working channel, and obtain the phase compensation table corresponding to the current temperature and the frequency of the working channel. The table determines the single-device phase compensation value when each gain device is in its respective receive gear.

Referring to the example in Figure 9, when the temperature of the environment where the AP is located is in the temperature range (T ₁ -ΔT ₁ , T ₁ +ΔT ₁ ), the frequency of the working channel is in the frequency band (fc ₁ -Δf ₁ , fc ₁ +Δf ₁ ) , the AP obtains the phase compensation table fc ₁ -T ₁ ; when the temperature of the environment where the AP is located is in the temperature range (T ₂ -ΔT ₂ , T ₂ +ΔT ₂ ), the working channel frequency is located in the frequency band (fc ₂ -Δf ₂ , fc ₂ +Δf ₂ ), the AP obtains the phase compensation table fc ₂ -T ₂ .

The method fully considers the influence of the receiving gear, temperature and working channel frequency of the gain device on the phase compensation value of the single device, improves the accuracy of the single device phase compensation value of the gain device, and further improves the accuracy of the phase compensation value of the radio frequency link. degree, which is equivalent to improving the accuracy of the AP's determination of the downlink equivalent channel matrix.

Further, the single-device phase compensation value of the gain device on the device gear in the phase compensation table can be understood as the phase compensation value of the gain device on the device gear for the signal at the center frequency. Therefore, the phase compensation value of the radio frequency link determined by the AP according to the phase compensation table is also the phase compensation value for the signal at the center frequency, which is equivalent to the phase compensation for the signal at the initial phase. Here, the phase compensation value of the radio frequency link determined by the AP according to the phase compensation table may be referred to as the initial phase compensation value of the radio frequency link.

In the embodiment of the present application, the AP can also determine the phase compensation value on each subcarrier, and adjust the uplink equivalent channel matrix of the corresponding subcarrier according to the phase compensation value on each subcarrier, so as to improve the accuracy of the signals transmitted by each radio frequency link of the AP .

In an example, the AP obtains the phase adjustment value of each subcarrier according to the subcarrier to which each uplink equivalent channel matrix belongs; the AP determines the sum of the initial phase compensation value of the radio link and the phase adjustment value of each subcarrier as each subcarrier. The phase compensation value of the subcarrier.

则确定出射频时延为

根据射频时延τ_RF确定第k个子载波的相位补偿值为

In another example, the AP may determine the radio frequency delay caused by the radio frequency link processing the radio frequency signal according to the initial phase compensation value of the radio frequency link, and then determine the phase compensation value on each subcarrier according to the radio frequency delay. For example, as in Equation (4), assume that the initial phase compensation value is

Then the radio frequency delay is determined as

Determine the phase compensation value of the kth subcarrier according to the radio frequency delay τ _RF as

Step 1203, the AP determines the transpose of the uplink equivalent channel matrix of the channel from the STA to the AP as the downlink equivalent channel matrix of the channel from the AP to the STA.

After determining the downlink equivalent channel matrix, the AP can generate a precoding matrix according to the downlink equivalent channel matrix, and then perform BF weighting according to the precoding matrix to determine the baseband signals of each transmitting radio frequency link. Based on the reciprocity compensation value, the AP performs reciprocity compensation on the baseband signals of each transmitting radio frequency link, and sends them to the STA.

In this technical solution, the AP receives the radio frequency signal from the STA through each radio frequency link, and the AP measures the radio frequency signal to obtain the uplink equivalent channel matrix of the channel from the STA to the AP. According to the uplink equivalent channel matrix and the phase compensation value of each radio frequency link , determine the downlink equivalent channel matrix of the channel from AP to STA, and solve the phase jump problem caused by the difference between the fixed link gear used in reciprocity calibration and the automatically adjusted link gear when receiving RF signals , to obtain the downlink equivalent channel matrix with higher accuracy. Further, the AP determines the precoding matrix according to the downlink equivalent channel matrix, and the AP performs BF weighting on the original baseband signal according to the precoding matrix to determine the baseband signal of each radio frequency link. Based on the reciprocity compensation value, the AP performs reciprocity compensation on the baseband signals of each transmitting radio link and sends it to the STA to increase the circuit gain of the BF, thereby improving the accuracy of the signals transmitted by each radio link of the AP.

Similar to the above concept, as shown in FIG. 13 , an embodiment of the present application further provides an AP. The AP can be used to implement the steps or processes in the above-mentioned embodiments of the phase compensation method or the phase calibration method.

The AP may include: a communication unit 1301 and a processing unit 1302 .

In this embodiment of the present application, the communication unit 1301 may also be referred to as a transceiver unit, and may include a sending unit and/or a receiving unit, respectively configured to perform the steps of AP sending and receiving in the above method embodiments.

Exemplarily, when the AP implements the functions of the AP in the process shown in FIG. 10:

The communication unit 1301 is configured to receive radio frequency signals from the STA through multiple radio frequency links, where each radio frequency link in the multiple radio frequency links includes at least two gain devices;

The processing unit 1302 is configured to measure the radio frequency signal and obtain a downlink equivalent channel matrix of the channel from the AP to the STA according to multiple phase compensation values, wherein the downlink equivalent channel matrix is the Transpose of the uplink equivalent channel matrix of the channel from the STA to the AP, the relationship between the plurality of phase compensation values and the plurality of radio frequency links is one-to-one correspondence, and the uplink equivalent channel matrix includes a plurality of rows vector, the relationship between the multiple row vectors and the multiple radio frequency links is one-to-one correspondence, each row vector of the uplink equivalent channel matrix is adjusted by the phase compensation value of the corresponding radio frequency link, the multiple Each of the phase compensation values is determined based on the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency chain.

In an optional implementation manner, the phase compensation value of the single device is a function of a variable, and the variable includes the frequency point of the working channel and the receiving gear of the corresponding gain device.

In an optional implementation manner, the variable further includes temperature.

In an optional implementation manner, the gain device includes an external low-noise amplifier, an internal low-noise amplifier or a variable gain amplifier.

In an optional implementation manner, each phase compensation value in the plurality of phase compensation values is the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency The adjustment value obtained by the subcarrier to which the effective channel matrix belongs.

Exemplarily, when the AP implements the functions of the AP in the process shown in FIG. 5:

the communication unit 1301, configured to transmit a first radio frequency signal by using a second radio frequency link; and receive a first radio frequency signal by using the first radio frequency link;

The processing unit 1302 is configured to process the first radio frequency signal with the first radio frequency link in the first state to obtain a first baseband signal, wherein the first radio frequency link includes at least two gain devices , the at least two gain devices include a first gain device, and the receiving gear of the first gain device in the first radio frequency link in the first state is in the gear to be measured, and except for the The receiving gears of the gain devices other than the first gain device are in their respective preset gears;

The processing unit 1302 is further configured to determine, according to the first baseband signal and the second baseband signal, a single-device phase compensation value when the first gain device is in the gear to be measured; the second baseband signal is the The processing unit 1302 uses the first radio frequency link in the second state to process the second radio frequency signal transmitted by the second radio frequency link, wherein the first radio frequency link in the second state The receiving gears of all gain devices in are in their respective preset gears; the initial phases of the first radio frequency signal and the second radio frequency signal are the same.

In an optional implementation manner, the single-device phase compensation value when the first gain device is in the gear to be measured is based on the phase difference between the phase of the first baseband signal and the phase of the second baseband signal. definite.

In an optional implementation manner, the first radio frequency signal or the second radio frequency signal includes multiple identical LTFs.

Similar to the above concept, as shown in FIG. 14 , an embodiment of the present application further provides an AP.

The AP may include: a scheduling module 1401, a compensation module 1402, and a calibration module 1403;

The scheduling module 1401 is used to schedule the compensation module 1402 or the calibration module 1403;

When the compensation module 1402 is scheduled, the AP implements the phase compensation function of the AP in FIG. 10; the compensation module 1402 is used to receive radio frequency signals from STAs through multiple radio frequency links; and measure the radio frequency signals and compensate for the multiple phases according to the value to obtain the downlink equivalent channel matrix of the channel from the AP to the STA.

When the scheduling calibration module 1403 is scheduled, the AP implements the phase calibration function of the AP in FIG. 5 ; the calibration module 1403 is used to process the second RF link transmission of the AP with the first RF link in the first state to obtain a first baseband signal; and according to the first baseband signal and the second baseband signal, determine the single-device phase compensation value of the first gain device when the first gain device is in the gear to be measured.

Similar to the above concept, FIG. 15 shows an AP provided by an embodiment of the present application, and the AP shown in FIG. 15 may be a hardware circuit implementation of the AP shown in FIG. 13 or FIG. 14 . The AP may be applicable to the flowchart shown in FIG. 5 or FIG. 10 to perform the functions of the AP in the above method embodiments. For convenience of explanation, FIG. 15 only shows the main components of the AP.

The AP includes a processor, memory, and multiple radio frequency links;

Exemplarily, each of the multiple radio frequency chains can be used as a receiving radio frequency chain or a transmitting radio frequency chain.

When the RF link is used as a receiving RF link, the RF link includes an eLNA, a mixer, an analog to digital converter (ADC), and a digital signal processor; when the RF link is used as a transmitting RF link, The RF chain includes PAs, mixers, digital to analog converters (DACs) and digital signal processors. Among them, the mixer includes iLNA and VGA.

Exemplarily, the receiving radio frequency link may process the received signal in the following manner: the radio frequency signal received from the antenna is sequentially amplified by eLNA, iLNA, and VGA; the amplified signal passes through the ADC, and finally passes through the digital signal processor. deal with. The transmitting radio frequency link can send signals in the following ways: after the baseband signal is processed by the digital signal processor, it can be converted into an analog signal by a DAC, and the analog signal is converted into a radio frequency signal by the up-conversion process of the mixer, and the radio frequency signal is processed by After PA processing, it radiates outward from the antenna.

When the AP executes the flowchart shown in FIG. 10 , the multiple radio frequency links may be multiple receiving radio frequency links.

Exemplarily, the multiple radio frequency chains are configured to receive radio frequency signals from the STA, and each radio frequency chain in the multiple radio frequency chains includes at least two gain devices;

The processor is configured to measure the radio frequency signal and obtain a downlink equivalent channel matrix of the channel from the AP to the STA according to multiple phase compensation values, where the downlink equivalent channel matrix is the STA Transpose of the uplink equivalent channel matrix of the channel to the AP, the relationship between the plurality of phase compensation values and the plurality of radio frequency links is one-to-one correspondence, and the uplink equivalent channel matrix includes a plurality of row vectors , the relationship between the plurality of row vectors and the plurality of radio frequency links is one-to-one correspondence, and each row vector of the uplink equivalent channel matrix is adjusted by the phase compensation value of the corresponding radio frequency link. Each of the phase compensation values is determined based on the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency chain.

In an optional implementation manner, the phase compensation value of the single device is a function of a variable, and the variable includes the frequency point of the working channel and the receiving gear of the corresponding gain device.

In an optional implementation manner, the variable further includes temperature.

In an optional implementation manner, the gain device includes an external low-noise amplifier, an internal low-noise amplifier or a variable gain amplifier.

In an optional implementation manner, each phase compensation value in the plurality of phase compensation values is the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency The adjustment value obtained by the subcarrier to which the effective channel matrix belongs.

When the AP executes the flowchart shown in FIG. 5, the multiple radio frequency links may be transmit radio frequency links and receive radio frequency links, wherein the transmit radio frequency link may be the second radio frequency link, and the receive radio frequency link may be the first radio frequency link a radio frequency link.

Exemplarily, the second radio frequency link is used to transmit the first radio frequency signal;

the first radio frequency link is in a first state, and the first radio frequency link in the first state is configured to receive the first radio frequency signal and process the first radio frequency signal to obtain a first baseband signal; the The first radio frequency link includes at least two gain devices, the at least two gain devices include a first gain device, and the reception of the first gain device in the first radio frequency chain in the first state The gear is in the gear to be tested, and the receiving gears of the gain devices other than the first gain device are in their respective preset gears;

The processor is configured to determine, according to the first baseband signal and the second baseband signal, a single device phase compensation value when the first gain device is in the gear to be measured; the second baseband signal is in the second The first radio frequency link in the state is obtained by processing the second radio frequency signal transmitted by the second radio frequency link, wherein the receiving files of all gain devices in the first radio frequency link in the second state are obtained The first radio frequency signal and the second radio frequency signal have the same initial phase.

In an optional implementation manner, the single-device phase compensation value when the first gain device is in the gear to be measured is based on the phase difference between the phase of the first baseband signal and the phase of the second baseband signal. definite.

In an optional implementation manner, the first radio frequency signal or the second radio frequency signal includes multiple identical LTFs.

It should be understood that the description of the apparatus embodiment corresponds to the description of the method embodiment. Therefore, for the content not described in detail, reference may be made to the above method embodiment, which is not repeated here for brevity.

Similar to the above concept, the present application also provides a computer program product, the computer program product includes: computer program code, when the computer program code is run on a computer, any one of the embodiments shown in FIG. 5 or FIG. 10 is executed. method is implemented.

Similar to the above concept, the present application also provides a computer-readable medium, the computer-readable medium stores a program code, when the program code is run on a computer, any one of the embodiments shown in FIG. 5 or FIG. 10 is implemented. method is implemented.

As will be appreciated by those skilled in the art, the embodiments of the present application may be provided as a method, a system, or a computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the present application. It will be understood that each process and/or block in the flowchart illustrations and/or block diagrams, and combinations of processes and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims (13)

1. a phase compensation method, is characterized in that, comprises: The access point AP receives radio frequency signals from the station STA through multiple radio frequency links, and each radio frequency link in the multiple radio frequency links includes at least two gain devices; The AP measures the radio frequency signal and obtains a downlink equivalent channel matrix of the channel from the AP to the STA according to a plurality of phase compensation values, where the downlink equivalent channel matrix is from the STA to the AP The transpose of the uplink equivalent channel matrix of the channel, the relationship between the multiple phase compensation values and the multiple radio frequency links is one-to-one correspondence, the uplink equivalent channel matrix includes multiple row vectors, the multiple The relationship between each row vector and the multiple radio frequency links is one-to-one correspondence, and each row vector of the uplink equivalent channel matrix is adjusted by the phase compensation value of the corresponding radio frequency link. Among the multiple phase compensation values Each phase compensation value of is determined based on the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency chain. 2 . The method of claim 1 , wherein the phase compensation value of the single device is a function of a variable, and the variable includes the frequency point of the working channel and the receiving gear of the corresponding gain device. 3 . 3. The method of claim 2, wherein the variable further comprises temperature. 4. The method of any one of claims 1 to 3, wherein the gain device comprises an external low noise amplifier, an internal low noise amplifier or a variable gain amplifier. 5. The method of any one of claims 1 to 3, wherein each phase compensation value in the plurality of phase compensation values is based on a respective single device of at least two gain devices in the corresponding radio frequency chain Determined by the sum of the phase compensation values, including: Each phase compensation value in the plurality of phase compensation values is obtained by adding the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency link and the sub-carriers to which the uplink equivalent channel matrix belongs. adjustment value. 6. The method of claim 4, wherein each phase compensation value in the plurality of phase compensation values is based on the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency chain certain, including: Each phase compensation value in the plurality of phase compensation values is obtained by adding the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency link and the sub-carriers to which the uplink equivalent channel matrix belongs. adjustment value. 7. An access point AP, characterized in that, comprising: processor, multiple RF links; The multiple radio frequency links are used to receive radio frequency signals from the station STA, and each radio frequency link in the multiple radio frequency links includes at least two gain devices; The processor is configured to measure the radio frequency signal and obtain a downlink equivalent channel matrix of the channel from the AP to the STA according to multiple phase compensation values, where the downlink equivalent channel matrix is the STA Transpose of the uplink equivalent channel matrix of the channel to the AP, the relationship between the plurality of phase compensation values and the plurality of radio frequency links is one-to-one correspondence, and the uplink equivalent channel matrix includes a plurality of row vectors , the relationship between the plurality of row vectors and the plurality of radio frequency links is one-to-one correspondence, and each row vector of the uplink equivalent channel matrix is adjusted by the phase compensation value of the corresponding radio frequency link. Each of the phase compensation values is determined based on the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency chain. 8 . The AP according to claim 7 , wherein the phase compensation value of the single device is a function of a variable, and the variable includes the frequency point of the working channel and the receiving gear of the corresponding gain device. 9 . 9. The AP of claim 8, wherein the variable further comprises temperature. 10. The AP according to any one of claims 7 to 9, wherein the gain device comprises an external low noise amplifier, an internal low noise amplifier or a variable gain amplifier. 11. The AP according to any one of claims 7 to 9, wherein each phase compensation value in the plurality of phase compensation values is a respective single-device phase of at least two gain devices in a corresponding radio frequency chain The sum of the compensation values is added to the adjustment value obtained according to the subcarriers to which the uplink equivalent channel matrix belongs. 12. The AP according to claim 10, wherein each phase compensation value in the plurality of phase compensation values is the sum of the respective single-device phase compensation values of at least two gain devices in the corresponding radio frequency chain Add the adjustment value obtained according to the subcarrier to which the uplink equivalent channel matrix belongs. 13. A computer-readable storage medium, characterized in that, a computer program or instruction is stored in the computer-readable storage medium, and when the computer program or instruction is executed, as in any one of claims 1 to 6 The described method is implemented.

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