CN102378216B - Method for transmitting uplink sounding reference signal - Google Patents

Abstract

A method for sending an uplink sounding reference signal, the method comprising: a base station configures at least two sets of sounding reference signal SRSs for a user UE, and the UE sends the respective corresponding sets of SRSs to the base station according to the period of each set of SRSs in the channel, for a total of Sending the at least two sets of SRS; the base station analyzes the channel information obtained from the at least two sets of SRS, and uses the reciprocity between the uplink channel and the downlink channel to transmit data with the UE in the channel. After applying the embodiment of the present invention, multiple sets of SRS detection can be used to jointly learn the channel information of the uplink channel and the downlink channel, which improves the flexibility of using SRS.

Description

A method for transmitting an uplink listening reference signal

technical field

The present invention relates to the technical field of communications, and more specifically, to a method for sending an uplink sounding reference signal.

Background technique

The uplink uses reference signals to perform uplink channel detection. Sounding Reference Signal (SRS, Sounding Reference Signal) is a kind of uplink reference signal, which is mainly used in determining uplink channel quality, frequency selective sounding (abbreviated as frequency selection characteristic), power control and uplink timing estimation, etc. SRS is not associated with uplink data or signaling. The base station notifies the user (UE) of the SRS parameters through high-level signaling or broadcasting. The UE periodically sends or triggers the SRS once. The base station obtains channel information such as uplink channel quality, frequency selection characteristics, and power control by receiving the SRS. The SRS parameters specifically include parameters such as SRS period, SRS sounding frequency subband, SRS construction pattern, comb teeth, code domain offset, and SRS transmission power.

However, with the rapid development of communication technology, the method of periodically or single-triggering SRS to detect channel quality is subject to certain limitations. For example, a UE in a coordinated multi-point transmission (CoMP) area needs to detect one or more channels of each cell. Since there is more than one cell in the CoMP area, it is difficult to have enough SRS resources to detect the channel to be tested in the process of periodically or once triggering the SRS to detect the channel. CoMP improves cell throughput, especially cell edge throughput, through coordinated transmission of base stations, thereby improving cell edge coverage and increasing transmission rates. For another example, when considering practical problems such as interference avoidance, the base station not only needs to perform channel detection on the frequency sub-band being used by the UE, but also needs to know the frequency selection characteristics in a wider frequency bandwidth range. However, the periodic or single-trigger SRS method for detecting channel quality is difficult to involve a wider frequency bandwidth because of the periodic or single-trigger SRS. For example, in uplink multi-antenna technology and uplink discontinuous resource scheduling, channel conditions of different frequency resources need to be known.

To sum up, the method of using SRS to detect channel quality has the problem that the detected channel information is limited, and a more flexible SRS mechanism is needed.

Contents of the invention

The embodiment of the present invention proposes a method for sending an uplink listening reference signal, which can use SRS to detect channel information of uplink channels and downlink channels, and solve the problem of limited channel information detected.

The technical scheme of the embodiment of the present invention is as follows:

A method for sending an uplink listening reference signal, the method comprising:

The base station configures at least two sets of SRSs for the user UE, and the UE sends the corresponding sets of SRSs to the base station according to the period of each set of SRSs in the channel, and sends the at least two sets of SRSs in total;

The base station analyzes the at least two sets of SRSs to obtain the channel information, and uses the reciprocity between the uplink channel and the downlink channel to transmit data with the UE in the channel.

The transmitting data with the UE on the channel includes the base station sending downlink data on the channel according to the channel information, or the base station instructing the UE to send uplink data on the channel according to the channel information.

The transmitting data with the UE on the channel includes that the base station sends downlink data on the channel according to information on the channel, and instructs the UE to send uplink data on the channel.

The period includes an infinitely recurring period or a finitely recurring period.

The channel includes frequency sub-bands, and sending the corresponding sets of SRS to the base station according to the period of each set of SRS in the channel includes sending the corresponding sets of SRS to the base station according to the period of each set of SRS in different frequency sub-bands. The SRS.

The periods of each set of SRS are integer multiples.

Multiple sets of SRS are sent at different times, and the short-period SRS is given priority.

When two sets of SRS are configured, the power of the two sets of SRS is not equal, the SRS with high power is sent to the base station of the non-local cell, and the SRS with low power is sent to the base station of the local cell.

The base station configuring at least two sets of SRS for the UE includes that the base station configures the UE with at least two sets of SRS, and informs the UE of the parameters of the at least two sets of SRS through the main carrier; the channel includes the main carrier and the member to be detected Carrier CC.

The channel includes non-continuously distributed frequency blocks in the carrier, and the sending of the corresponding sets of SRS to the base station in the channel according to the period of each set of SRS to the base station includes sending the base station to the base station according to the period of each set of SRS in different frequency blocks. Send the SRS of their corresponding sets.

Configuring at least two sets of SRS for the UE by the base station includes configuring at least two sets of SRS for the UE by the base station, and informing the UE of the parameters of the at least two sets of SRS through the main carrier; the channel includes an activated carrier and an inactive carrier; the Sending the corresponding sets of SRSs to the base station according to the period of each set of SRSs in the channel includes sending the corresponding sets of SRSs to the base station according to the period of each set of SRSs in the activated carrier and/or the inactive carrier.

Before the base station configures at least two sets of SRSs for the UE, it further includes: determining the frequency subbands that are not detected by the configured at least two sets of SRSs from the downlink channel measurement signal, and the frequency subbands detected by the downlink channel measurement signal are the same as the frequency subbands detected by the downlink channel measurement signal The frequency subbands detected by the SRS are complementary; the downlink reference signal detects channel information when the SRS is not sent.

The SRS is configured by the base station according to the number of logical ports of the UE.

The at least two sets of SRS are independent or related.

The method further includes triggering SRS or deactivating SRS.

It can be seen from the above technical solutions that in the embodiment of the present invention, the base station configures at least two sets of SRSs for the UE, and the UE sends the corresponding sets of SRSs to the base station according to the cycle of each set of SRSs in the channel, and sends the at least two sets of SRSs in total. Two sets of SRS, compared with one set of SRS in the prior art, increases the scope of detecting channel information; the base station analyzes the at least two sets of SRS to obtain the corresponding channel information, and utilizes the reciprocity between the uplink channel and the downlink channel, Data is transmitted to the UE in the corresponding downlink channel. Through multiple sets of SRSs periodically detecting the channel information of the uplink channel and the downlink channel, the detected channel information is more abundant and flexible, and compared with the prior art, the effectiveness of the detection is greatly increased.

Description of drawings

Fig. 1 is the schematic diagram that the embodiment of the present invention utilizes SRS and downlink channel measurement signal to detect uplink channel situation and downlink channel situation;

FIG. 2 is a schematic diagram of the frequency domain location of the SRS in Embodiment 1 of the present invention;

3 is a schematic diagram of the positions of multiple sets of SRSs in Embodiment 2 of the present invention;

FIG. 4 is a schematic diagram of carrier positions in Embodiment 6 of the present invention;

FIG. 5 is a schematic diagram of frequency domain locations where two sets of SRSs are located in Embodiment 7 of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clearly, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

In the embodiment of the present invention, the base station configures at least two sets of SRS for the UE, and the UE sends the corresponding set of SRS to the base station in the uplink channel at the period of each set of SRS itself, and at least two sets of SRS are sent in the channel. Sending a set of SRS periodically expands the flexibility of probing the channel. The base station analyzes the received SRS, and obtains channel information from the SRS. Using SRS not only directly detects channel information, but also utilizes the characteristics of uplink and downlink reciprocity of wireless channels, the base station can know uplink channel information from the received SRS, because at least two sets of SRS are sent in the present invention, that is, all detected channels can The downlink data is sent in the middle, or the base station informs the UE of the detected information, and the UE sends the uplink data in all the detected channels according to the information; it can also send the downlink data in some SRS detection channels, and the base station informs the UE of the detected information, The UE sends uplink data in some SRS sounding channels according to the information. The detection information brought by the SRS for detecting the uplink channel and the SRS for detecting the downlink channel according to the reciprocity can bring the information about the UE and the channel to the base station, thereby providing support for the accurate use of the uplink and downlink channels. Through the above method, the base station comprehensively uses multiple sets of SRS detection information to serve multiple cells and multiple purposes, increasing the flexibility of the SRS. And solve the problem that the detected channel information is limited.

First, the base station configures at least two sets of SRSs for the UE, and the UE sends at least two sets of SRSs to the base station in the uplink channel at the period of each set of SRSs, and the base station analyzes the received SRSs to obtain uplink channel information. Utilizing the reciprocity of the uplink and downlink channels, the base station sends data to the UE in the downlink channel according to the uplink channel information. When multiple sets of SRSs are not sent at the same time, the SRS with a shorter period is given priority in order to obtain channel information faster. The period of the SRS includes the following two types: 1. Sending the SRS in an infinite cycle, triggering the SRS and stopping the SRS through signaling; 2. Specifying the number of times to send the SRS, that is, the period of the limited cycle.

In addition, in the prior art, the base station periodically sends downlink channel measurement signals to the UE. Referring to FIG. 1 , it is a schematic diagram of detecting uplink channel conditions and downlink channel conditions by using SRS and downlink channel measurement signals according to an embodiment of the present invention. The black square in the figure represents that the UE sends the SRS to the base station according to the SRS period. After analyzing the received periodic downlink channel measurement signal, the UE obtains a downlink channel measurement report. The white square represents that the UE reports the downlink channel measurement report to the base station. According to the reciprocity of the uplink and downlink channels, the present invention can make full use of the downlink channel measurement signals periodically sent by the base station to measure the downlink channel, and the UE can also provide the downlink channel information to the base station.

For example, it is considered that the downlink channel information reported by the UE is used as a supplement to the SRS detection, and the frequency subbands detected by the downlink channel measurement signal are set as frequency subbands not detected by multiple sets of SRS. The frequency subbands detected by the downlink channel measurement signal are complementary to the frequency subbands detected by multiple sets of SRSs. Since the frequency subbands of the downlink channel measurement report reported by the UE are complementary to the frequency subbands of multiple sets of SRS detection, the range of channel detection is increased without increasing the SRS, and the transmission of SRS can be saved and optimized. The downlink channel information reported periodically by the UE and the periodic detection of multiple sets of SRSs combine the uplink and downlink channel information, enhancing the real-time and accurate understanding of the channel.

Embodiment one

Referring to Fig. 2, it is a schematic diagram of the location of frequency subbands where the SRS is located in Embodiment 1 of the present invention. The frequency of SRS1 detection is higher, and the frequency of SRS2 detection is lower. The information of multiple sets of SRSs is used to detect the frequency subbands, and the corresponding sets of SRSs are sent to the base station according to the own period of each set of SRSs in the frequency subbands. The frequency subbands detected by multiple sets of SRS are staggered, that is, each set of SRS detects the frequency subbands of interest. Thereby, different frequency sub-bands are detected.

Embodiment two

Refer to Figure 3 for a schematic diagram of the positions of the two sets of SRSs in Embodiment 2 of the present invention. The two sets of SRSs perform coordinated detection according to their own periods. The periods of the two sets of SRSs are different, and the frequency sub-bands to be detected are also different. The period of SRS2 is an integer multiple of SRS1, SRS2 detects a frequency subband with a higher frequency, and SRS1 detects a frequency subband with a lower frequency. The frequency sub-bands detected by the long-period SRS2 can be complementary to the frequency sub-bands detected by the short-period SRS1, that is, the frequency positions are staggered from each other to reduce the repeated detection part. For more than two sets of SRS, the periods of each set of SRS are integer multiples. For example, the period of SRS1 is 5s, the period of SRS2 is 10s, and the period of SRS3 is 25s.

For example, one set of SRSs performs channel detection in the frequency subband being called, and another set of SRSs performs channel detection in other frequency subbands. When the frequency sub-band being called is interfered, since the SRS can timely feed back the information of other frequency sub-bands, the base station can quickly transfer the data originally sent in the frequency sub-band being called to other frequency sub-bands for transmission, optimizing resource utilization scheduling. Similarly, more than two sets of SRS can also be sent for coordinated detection. The same specific process of sending more than two sets of SRS is the same as that of two sets of SRS, so it will not be repeated in this article.

Embodiment Three

A UE in a CoMP area needs to detect one or more channels of each cell. Since there is more than one cell in the CoMP area, one or more sets of SRS defined according to the CoMP area SRS coordination can also be sent to prepare for CoMP implementation. When sending two sets of SRS, one set of SRS is sent with higher power, which is convenient for other base stations to receive; the other set of SRS is sent with lower power to directly contact the base station of the cell in order to measure the channel information of the cell. When sending more than two sets of SRS, the power of each set of SRS is determined according to specific requirements.

Embodiment four

Carrier aggregation means that through joint scheduling and use of resources on multiple component carriers (CCs), the system can support a maximum bandwidth of 100 MHz, thereby achieving a higher system peak rate. In the case of frequency aggregation, the UE can send SRSs on multiple carriers that need to be detected according to the respective periods of each SRS, so that channel information of multiple carriers can be obtained, laying the foundation for more effective use of CC.

Carriers in carrier aggregation include Primary Carrier (PCC) and CC. The primary carrier is the original carrier before carrier aggregation. There are two types of CCs: one is that the CC has its own control channel, which is generally called a secondary carrier (SCC); the other is that the CC does not have its own control channel, which is generally called an extended carrier (Extended CC). The UE receives all SRS parameters sent by the base station in the main carrier, and then the UE sends the SRS in the main carrier and the auxiliary carrier; or, the UE sends the SRS in the main carrier and the extension carrier.

Embodiment five

In the development of wireless technology, UE uplink resource allocation supports discontinuous resource allocation, that is, there are multiple frequency blocks discontinuously distributed in the same carrier. In the existing SRS channel detection method, since only one set of SRS can be sent, only continuously distributed frequency blocks can be detected, and discontinuous frequency blocks cannot be accurately detected.

The base station configures at least two sets of SRSs for the UE, and sends SRSs to the base station according to the period of each set of SRSs on frequency blocks with discontinuous carrier distribution, so that discontinuous resources can be accurately detected.

Embodiment six

If there are inactive carriers in carrier aggregation, the base station configures the UE with at least two sets of SRS, and informs the UE of the parameters of the at least two sets of SRS through the main carrier, and sends at least The two sets of SRS signals utilize the uplink and downlink reciprocity, so that the information of the inactive carrier and the activated carrier can be obtained. An inactive carrier refers to an unused component carrier in carrier aggregation. The activated carrier refers to the component carrier and main carrier being used in carrier aggregation.

In Fig. 4a, the activated carriers of the uplink carrier include carrier 1 and carrier 2 as main carriers, and the activated carriers of the downlink carrier include carrier 1 and carrier 2 as main carriers. The number of activated carriers of the uplink carrier and the number of activated carriers of the downlink carrier are the same and symmetrical. Among the uplink carriers, there is an inactive carrier, that is, carrier 3 , and among the downlink carriers, there is an inactive carrier, that is, carrier 3 . Not only the SRS is sent on the active carrier, but also the SRS is sent on the inactive carrier. Although the unactivated carrier is in an unused state, once the unactivated carrier needs to be used, the information of the unactivated carrier can be quickly obtained.

In Fig. 4b, the activated carriers of the uplink carrier include carrier 1, which is the main carrier, and the activated carriers of the downlink carrier include carrier 1 and carrier 2, which are the main carriers. The number of activated carriers of the uplink carrier is different from the number of activated carriers of the downlink carrier. Among the uplink carriers are inactive carriers, that is, carrier 2 and carrier 3 , and among the downlink carriers, there is an inactive carrier, that is, carrier 3 . The number of activated carriers of the uplink carrier is asymmetric to the number of activated carriers of the downlink carrier, but there are inactive carriers in both the uplink carrier and the downlink carrier. Not only the SRS is sent on the active carrier, but also the SRS is sent on the inactive carrier. Although the unactivated carrier is in an unused state, once the unactivated carrier needs to be used, the information of the unactivated carrier can be quickly obtained.

Embodiment seven

For example, when the UE has four transmit antennas, three port modes are configured according to the number of antenna ports. That is, 1 logical port mode, 2 logical port mode, and 4 logical port mode. The base station configures different SRSs according to the logical port mode of the UE. For example, one set of SRS is configured for 1 logical port mode, one set of SRS is configured for 2 logical port modes, and one set of SRS is configured for 4 logical port mode.

Wherein, each set of SRSs of each logical port may be independent or related to each other. Referring to accompanying drawing 5, the periods of the two sets of SRS are different. Moreover, the period of SRS2 has no relationship with the period of SRS1. SRS2 and SRS1 are independent of each other and each detects a different frequency. How multiple sets of SRSs are related is not a key technology in the present invention, and will not be described in detail here. Each set of SRS can be activated at the same time during configuration, or the UE can first save the parameters of each set of SRS, and then activate or stop a certain set of SRS according to other methods.

For example, a UE in a multi-cell cross coverage area may be in the cross coverage of a macro base station, or in the cross coverage of a macro base station and a micro base station. The UE runs a set of SRS in the local cell in a certain logical port mode, and can also run a set of SRS suitable for cross-coverage areas in the local cell in another logical port mode to perform useful channel detection and power measurement.

Wherein, different SRSs may be reflected in different SRS structural patterns, or in the case of the same SRS structural patterns, other parameters are different.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (15)

1. A method for sending an uplink listening reference signal, characterized in that the method comprises: The base station configures at least two sets of SRSs for the user UE, and the UE sends the corresponding sets of SRSs to the base station according to the period of each set of SRSs in the channel, and sends the at least two sets of SRSs in total; The base station analyzes the at least two sets of SRSs to obtain the channel information, and uses the reciprocity between the uplink channel and the downlink channel to transmit data with the UE in the channel; The use of the reciprocity between the uplink channel and the downlink channel includes: using the downlink channel information reported by the UE as a supplement to the SRS detection, setting the frequency subbands detected by the downlink channel measurement signal as at least two sets of frequency subbands not detected by the SRS, The frequency subbands detected by the downlink channel measurement signal are complementary to the frequency subbands detected by at least two sets of SRSs. 2. The method for sending an uplink sounding reference signal according to claim 1, wherein the transmitting data with the UE in the channel comprises that the base station sends downlink data in the channel according to the information of the channel, Or, the base station instructs the UE to send uplink data on the channel according to the channel information. 3. The method for transmitting an uplink sounding reference signal according to claim 1, wherein the transmitting data with the UE in the channel comprises that the base station transmits downlink data in the channel according to the information of the channel, And instruct the UE to send uplink data on the channel. 4 . The method for sending an uplink sounding reference signal according to claim 1 , wherein the cycle includes an infinite cycle cycle or a limited cycle cycle. 5 . 5. The method for sending an uplink sounding reference signal according to claim 1, wherein the channel includes a frequency subband, and sending the corresponding sets of SRS to the base station according to the cycle of each set of SRS in the channel includes , sending the corresponding sets of SRSs to the base station in different frequency subbands according to the cycle of each set of SRSs. 6 . The method for sending an uplink sounding reference signal according to claim 1 , wherein the period of each set of SRS is an integer multiple. 7 . 7. The method for sending an uplink sounding reference signal according to claim 1 or 6, characterized in that multiple sets of SRS are sent at different times, and short-period SRSs are sent preferentially. 8. The method for transmitting an uplink listening reference signal according to claim 1, wherein when two sets of SRSs are configured, the powers of the two sets of SRSs are unequal, and the SRS with high power is sent to a base station other than the own cell, The SRS with low power is sent to the base station of the cell. 9. The method for sending an uplink sounding reference signal according to claim 1, wherein the base station configuring at least two sets of SRSs for the UE comprises configuring the UE with at least two sets of SRSs, and notifying the UE of the SRSs through the main carrier The at least two sets of SRS parameters; the channel includes the main carrier and the component carrier CC to be detected. 10. The method for transmitting an uplink sounding reference signal according to claim 1, wherein the channel includes frequency blocks discontinuously distributed in the carrier, and the channel transmits each set of SRS to the base station according to its own cycle of each SRS The corresponding set of SRSs includes sending the respective corresponding sets of SRSs to the base station according to the period of each set of SRSs in different frequency blocks. 11. The method for sending an uplink sounding reference signal according to claim 1, wherein the base station configures at least two sets of SRSs for the UE, comprising: the base station configures the UE with at least two sets of SRSs, and informs the UE of the SRSs through the main carrier The parameters of the at least two sets of SRS; the channel includes an activated carrier and an inactive carrier; the sending of the corresponding set of SRS to the base station according to the cycle of each set of SRS in the channel includes, on the activated carrier and/or the The SRSs of the corresponding sets are sent to the base station according to the cycle of each set of SRSs in the inactivated carriers. 12. The method for transmitting an uplink sounding reference signal according to claim 5, wherein the base station further includes, before configuring at least two sets of SRSs for the UE, determining that the configured at least two sets of SRSs are not detected by a downlink channel measurement signal The frequency subband detected by the downlink channel measurement signal is complementary to the frequency subband detected by the SRS; the downlink reference signal detects channel information when the SRS is not sent. 13. The method for sending an uplink sounding reference signal according to claim 1, wherein the SRS is configured by the base station according to the logical port mode of the UE. 14. The method for sending an uplink sounding reference signal according to claim 1, wherein the at least two sets of SRS are independent or correlated. 15. The method for sending an uplink sounding reference signal according to claim 1, further comprising triggering SRS or stopping SRS.

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