WO2013037269A1

WO2013037269A1 - Data sending method and device

Info

Publication number: WO2013037269A1
Application number: PCT/CN2012/080813
Authority: WO
Inventors: 高磊; 罗龙
Original assignee: 华为技术有限公司
Priority date: 2011-09-16
Filing date: 2012-08-31
Publication date: 2013-03-21
Also published as: CN103002558B; CN103002558A

Abstract

The embodiments of the present invention relate to a data sending method and device. The data sending method includes: sending data to at least two sites simultaneously; if data sending on a first site of the at least two sites is over, and a second site on which data sending is not over exists among the remaining sites, then reassigning the power used for sending data on the first site into that used for sending data on the second site. The data sending method according to the embodiments of the present invention efficiently utilizes the power of the access point in sending data, and avoids power waste resulting from the unequal length of data sent to each site in MU-MIMO and so on.

Description

Data transmission method and device

The present application claims priority to Chinese Patent Application No. 2011-1027537, filed on Sep. 16, 2011, the entire disclosure of which is hereby incorporated by reference. TECHNICAL FIELD The present invention relates to the field of wireless communications, and more particularly to a data transmitting method and apparatus. Background of the Invention A Basic Service Set (BSS) is an essential part of a Wireless LAN. A station (Station, referred to as STA) that is within a certain coverage area and has some kind of association forms a BSS. The most basic form of association is that sites communicate directly with each other in a self-organizing network, which is called an independent BSS. A more common scenario is that the STA is associated with a central site called the Access Point (AP) that manages the BSS. The BSS built around the AP is called the BSS with infrastructure. BSS with basic implementations can be interconnected by their APs through a distributed system.

The important concept of Transmission Opportunity (TX0P) is introduced in the 802. lie protocol revision. A TX0P refers to a bounded period in which a station can transmit a specific communication category. The station obtains TX0P through competition, and once the TX0P is obtained, the station can transmit data frames, control frames and management frames, and receive response frames. Different from the normal STA in the BSS, the AP may have multiple direct data transmission objects. Therefore, when the AP obtains TX0P, there may be more than one data transmission object within one TX0P.

Multi-user Multiple Input Multiple Output (MU-MIM0) is a MIM0 technology that transmits different data to multiple users at the same time. User pairing and weighting are performed by the transmitter (Beamformer). Moment, the same Data is transmitted to multiple users on one frequency band, and interference between users is kept as small as possible.

Taking 802. l lac as an example, in the latest draft 802. l lac standard, for the AP data downlink, the TX0P sharing mode under MU-MIM0 is defined. In this mode, multiple APs can share one TX0P, in MU- Simultaneous transmission in MIM0 mode can save a lot of frequency resources. In MU-MIM0 mode, there may be cases where the data lengths of the users are not equal. At this time, the data lengths of all users are equal by padding. Filling in users with short data lengths may result in a large amount of meaningless data, resulting in wasted resources.

SUMMARY OF THE INVENTION An object of embodiments of the present invention is to provide a data transmission method and apparatus that fully utilizes the transmission power of an access point.

According to an embodiment of the present invention, a data sending method is provided, where the method includes: simultaneously transmitting data to at least two stations;

If the data of the first station in the at least two stations is sent, and the remaining station still has the second station whose data is not sent, the power for transmitting the data of the first station is adjusted to be used for sending The data of the second site.

According to an embodiment of the present invention, a device for data transmission is provided, where the device includes: a transmitter, configured to simultaneously send data to at least two stations;

a first processor, configured to send data of the first site if there is still a second site in the remaining sites that has not been sent after the data of the first site in the at least two sites is sent The power is adjusted to transmit data of the second site, and the transmitter is notified.

The data transmission method according to the embodiment of the present invention effectively utilizes the power of the data transmitted by the access point, and avoids power waste caused by the unequal length of data sent to each station in the MU-MIM0. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description are only the present drawings. Some embodiments of the invention may be obtained by those of ordinary skill in the art from the drawings without departing from the scope of the invention.

1 is a sequence diagram of an AP transmitting data to a STA;

2 is a flowchart of a data transmitting method according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an apparatus for data transmission according to an embodiment of the present invention.

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, but not all embodiments. . All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Figure 1 is a timing diagram of an AP transmitting data to a STA. For convenience of explanation, FIG. 1 exemplarily shows that the AP simultaneously transmits data of 4 STAs, which are numbered STA1, STA2, STA3, and STA4. Those skilled in the art will appreciate that the number of STAs may be more or less than the number shown in Figure 1. As shown in Figure 1, during the TO time period, the AP needs to send data of 4 STAs. At the end of the TO time period, the data sent by STA2 has been sent. At the end of the T1 time period, the STA3 data has also been sent. Further, at the end of the T2 time period, the data of STA1 has also been transmitted, and only the data of STA4 remains in the T3 time period.

According to the case of the data transmission, the embodiment of the present invention provides a data transmission method, which can effectively utilize the transmission power of the AP.

2 is a flow diagram of a data transmission method 200 in accordance with an embodiment of the present invention. As shown in Figure 1, Method 200 includes:

21 0: Send data to at least two sites simultaneously;

The foregoing step 21 0 may specifically be: sending data to the at least two sites simultaneously according to power weights allocated to the at least two sites;

220: If the data of the first station in the at least two stations is sent, and the remaining station still has the second station whose data is not sent, adjust the power of the data used to send the first station to be used for Sending data of the second site.

The second station described above is a phase shift keying modulated station.

The first site and the second site shown in Fig. 2 are merely for convenience of description and are not intended to limit the scope of the embodiments of the present invention. Similarly, the third site described below is only for the convenience of description. The implementation process of the embodiment of the present invention will be described in detail below with reference to FIG.

In the process of transmitting data shown in FIG. 1, in the TO time period, the AP transmits the data of each STA by using the corresponding power according to the weight vector of the power of the data of each STA. For example, for the four STAs in Figure 1, the weighting matrix can be as shown in equation (1):

Where ^^^ is the weight vector of the power of the STA1 STA3 data, which can be specifically set according to the specific situation. In general, the weighting matrix performs power normalization, which is normalized according to equation (2):

Where F is the F norm.

By the end of the TO period, the data sent by the AP to the STA2 has been transmitted, so the power for transmitting the STA2 data can be adjusted to the data for transmitting the other three STAs in the T1 period. In the T1 time period, the weight vector corresponding to the power of transmitting data to STA2 in the weighting matrix may be set to 0, and the weighting matrix becomes equation (3):

In this embodiment, the STA is referred to as a first station, and the first station may be multiple. For example, in an embodiment not shown, the data of the plurality of STA2s may be adjusted to be used to transmit the remaining data when the data of the plurality of STA2s has been transmitted at the end of the TO period. STA's data. In the embodiment of the present invention, for convenience of description, the STA whose data has not been transmitted at the end of the TO period may be referred to as a second station.

Since the power variation causes distortion of the constellation for quadrature amplitude modulation (QAM), once the powers allocated to STA1, STA3, and STA4 change, and these STAs Both are QAM modulation, then this power change must be communicated to the STA through some mechanism. For Pha se Shift Keying (PSK) modulation, since the constellation point itself only contains phase information, the scaling of the amplitude does not affect the demodulation, and the embodiment of the present invention only considers the PSK. Notify the STA of the power change.

According to an embodiment of the present invention, it is determined at this time whether STA1, STA3, and STA4 belong to a PSK-modulated STA. If STA1, STA3, and STA4 do not belong to the PSK-modulated STA, the power weight vector of the data for transmitting each STA remains unchanged during the subsequent T1, Τ2, and Τ3 time periods.

If the TO time period is determined, for example, STA1 is a PSK-modulated STA, the power of the data for transmitting STA2 is adjusted to the data for transmitting STA1, and the normalized weighting matrix is:

If the TO time period is over, it is determined that, for example, STA1 and STA3 are PSK-modulated STAs, that is, there are multiple STAs at the second station, the power for transmitting STA2 data is adjusted to be used for transmitting STA1 and STA3 data, for example, The power used to transmit STA2 data is adjusted according to the percentages A and B. The data of STA1 and STA3 are respectively transmitted, and it is required to satisfy A+B=100% at this time. A and B may be equal or unequal, for example, A = 50%, B = 50%, or A = 30% and B = 70%. Those skilled in the art can preset the sizes of A and B according to the specific requirements of the transmitted data. In this case, the normalized weighting matrix is:

If the TO time period is over, it is determined that, for example, STA1, STA3, and STA4 are PSK-modulated STAs, that is, there are multiple STAs, and the AP adjusts the power for transmitting data to STA2 to be used for transmitting STA1 in the T1 period. The STA3 and STA4 data, for example, adjust the power of the data for transmitting STA2 by the percentages A, B, and C to transmit the data of STA1, STA3, and STA4, respectively, and it is required to satisfy A+B+C=100%. A, B and C may be equal or unequal, for example A=33.3%, B=33.3%, C=33.3%, A=30%, B=20% and C=50% . Those skilled in the art can preset the sizes of A, B, and C according to the specific requirements of the transmitted data. In this case, the normalized weighting matrix is:

(6)

At the end of the Tl time period, the STA3 data has also been sent, that is, the data of one of the second stations has been transmitted. At this time, the AP can adjust the power of the data used by the AP to send STA2 and STA3 to be used for the T2 time period. Send data of STA1 and STA4. For convenience of description, in the embodiment of the present invention, the STA whose data has not been transmitted at the end of the T1 time period may be referred to as a third station, that is, STA1 and STA4 are third sites. First, the weight vector corresponding to the power of transmitting data to STA2 and STA3 in the weighting matrix is set to 0, and the weighting matrix becomes equation (7):

Since in the embodiment of the invention, the third station needs to be a PSK modulated STA. Thus, in At the end of the Tl time period, the AP needs to confirm whether STA1 and STA4 are PSK modulated STAs. If the AP confirms that STA1 is a PSK-modulated STA, and STA4 is not a PSK-modulated STA, the AP may adjust the power of the data for transmitting STA2 and STA3 to the data for transmitting STA1 in the T2 period, and normalize at this time. The weighting matrix is:

If the AP determines that both STA1 and STA4 are PSK-modulated STAs, that is, there are multiple third stations, the AP may adjust the power for transmitting STA2 and STA3 data to be used for transmitting STA1 in the T2 time period. And the data of STA4, for example, the power for transmitting the data of STA2 and STA3 is adjusted to the data for transmitting STA1 and STA4 according to the percentages D and E, respectively, and it is required to satisfy D+E=100%. D and E may be equal or unequal, such as D=50%, E=50%, or D=30% and E=70%. Those skilled in the art can preset the sizes of D and E according to the specific requirements of the transmitted data. In this case, the normalized weighting matrix is:

(9)

By the end of the T2 period, the data sent by the AP to STA1 is also sent. If the AP determines that STA4 is a PSK-modulated STA, the AP may adjust the power of the data for transmitting STA1, STA2, and STA3 to the data for transmitting STA4 in the T3 period, where the normalized weighting matrix is:

According to an embodiment of the present invention, the PSK mentioned herein includes, but is not limited to, Binary Phase Shift Keying (BPSK) modulation, Quadrature Phase Shift Keying (QPSK) modulation, and eight phases. Phase Phase Shift Keying (8PSK). The data transmission method according to the embodiment of the present invention effectively utilizes the power of the data transmitted by the access point, and avoids power waste caused by the unequal length of data sent to each station in the MU-MIM0.

3 is a schematic structural diagram of an apparatus for transmitting data according to an embodiment of the present invention. The apparatus shown in Figure 3 can be used as an access point to implement an embodiment of the method of the present invention. As shown in Figure 3, device 300 includes:

a transmitter 31 0, configured to simultaneously send data to at least two stations;

Optionally, the foregoing transmitter 31 is specifically configured to simultaneously send data to the at least two sites according to power weights allocated for the at least two sites.

The first processor 320 is configured to: if there is still a second station in the remaining stations that has not been sent after the data of the first station in the at least two stations is sent, the first station is used to send the first station. The power of the data is adjusted to transmit data of the second station, and the transmitter 31 0 is notified.

After receiving the notification from the first processor 320, the transmitter 31 0 uses the power of the data previously used to transmit the first station to send data to the second station. The features of the method embodiments of the present invention, where appropriate, apply to the apparatus embodiments of the present invention, and vice versa.

The structure of the device 300 of the embodiment of the present invention will be exemplified in conjunction with the above examples. For example, the transmitter 31 0 transmits data to STA1 to STA4 according to the normalized weighting matrix defined by the equation (2). Upon transmitting data to the first station, e.g., STA2, processor 320 determines if there is a PSK-modulated second station among the remaining STA1, STA3, and STA4. For example, the processor 320 determines that the STA1 is a PSK-modulated STA, that is, the second station, and the processor 320 adjusts the power for transmitting the STA2 data to the data for transmitting the STA1 according to the above formula (4).

According to an embodiment of the present invention, if there are multiple second sites, for example, STA1 and STA3 are PSK-modulated STAs, the first site is sent according to a percentage preset for each second site. The portion of the corresponding percentage of the power of the data is adjusted to transmit the data of each of the second stations, and the transmitter is notified, wherein the sum of the percentages preset for each of the second stations is equal to 100%; The transmitter is configured to send a notification before receiving the processor The power of the data of the first site is used to send data to the second site.

For example, the processor 320 adjusts the power of the data for transmitting STA2 according to the above formula (5) to the data for transmitting STA1 and STA3 according to the percentages A and B, respectively, at which time it is required to satisfy A+B=100%. A and B may be equal or unequal, such as A = 50%, B = 50%, or A = 30% and B = 70%.

According to an embodiment of the present invention, if there are multiple second sites, the device 300 further includes a second processor 330, configured to: when the data of the at least one second site is sent, if the remaining second sites are There is also a third station whose data has not been sent, the power for transmitting the data of the second station is adjusted to transmit data of the third station, and the transmitter 310 is notified; the transmitter receives After the notification by the second processor, the power of the data previously used to transmit the second station is used to send data to the second station.

For example, at the end of the T1 time period, the second processor 330 confirms that STA1 is a PSK-modulated STA, that is, STA1 is a third station, and then the processor 330 allocates the data to be sent to STA2 and STA3 according to formula (8). The power of the data is allocated to the transmitting unit 310 for transmitting data to STA1.

According to the embodiment of the present invention, if there are multiple third sites, the second processor 330 is specifically configured to send the second site according to a percentage preset for each third site. The portion of the corresponding percentage of the power of the data is adjusted to transmit the data of each of the third stations, and the transmitter is notified, wherein the sum of the percentages preset for each of the third stations is equal to 100%; After receiving the notification from the second processor, the transmitter uses the power for transmitting the data of the second station to send data to the third station. For example, the second processor 330 determines that STA1 and STA4 are both PSK-modulated STAs, that is, the third station is multiple, and the second processor 330 adjusts the power for transmitting the data of STA2 and STA3 to be used for transmitting STA1 and The data of STA4, for example, the power of data for transmitting STA2 and STA3 is adjusted according to the formula (9) according to the percentages D and E, respectively, to data for transmitting STA1 and STA4, at which time it is required to satisfy D+E=100%. D and E may be equal or unequal, for example, D = 50%, E = 50%, or D = 30% and E = 70%.

According to an embodiment of the present invention, the first site may be multiple. For example, in the not shown In an embodiment, the data sent to the multiple STAs 2 may be transmitted at the end of the TO time period, and the first processor 320 adjusts the power of the data for sending the multiple STAs 2 to send the Data of the second station, and notifying the transmitter 310; after receiving the notification of the first processor 310, the transmitter 310 transmits the power of the data used to send the multiple first stations to send the first Two site data.

The first processor 310 and the second processor 320 may be two independent processors or a processor integrated with functions.

The device 300 described in the embodiment of the present invention may be used to perform all the steps performed by the AP in the foregoing method embodiment, and has been described in detail in the method embodiment, and thus is not described herein again.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technology solution. A person skilled in the art can use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

A person skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided herein, it should be understood that the disclosed systems, devices, and methods may be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form. The components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium, including The instructions are used to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM, Random Acces s Memory), a disk or an optical disk, and the like, and the program code can be stored. Medium.

The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the claims.

Claims

Rights request

A data transmission method, the method comprising:

Send data to at least two sites simultaneously;

2. The method of claim 1 wherein the second station is a phase shift keying modulated station.

The method according to claim 1 or 2, wherein the simultaneously transmitting data to at least two stations comprises:

The power weights assigned to the at least two stations simultaneously transmit data to the at least two sites simultaneously.

4. The method of claim 1 or 2, wherein

If the number of the second sites is different, the data used to send the data of the first site is adjusted to send data of the second site, including:

Adjusting, according to a percentage preset for each second site, a portion of the corresponding percentage of power used to transmit data of the first site to transmit data for each of the second sites, wherein the The sum of the percentages preset by the second site is equal to 100%.

The method according to claim 1 or 1, wherein the second site has multiple, the method further includes:

When the data of the at least one second station is sent, if there is still a third station in the remaining second station that the data has not been sent;

The power for transmitting the data of the second station is adjusted to transmit data of the third station.

6. The method of claim 5, wherein If the third site has multiple, the power used to send the data of the second site is adjusted to send data of the third site, including:

Adjusting, according to a percentage preset for each third site, a portion of the power percentage for transmitting the data of the second site to transmit data of each of the third sites, wherein the each is The sum of the percentages preset by the third station is equal to 100%.

7. The method of claim 4, wherein

The percentages preset for each of the second stations are equal or unequal.

8. The method of claim 6 wherein:

The percentages preset for each of the third stations are equal or unequal.

9. The method of claim 1 or 2, wherein

The first site is a plurality.

10. A device for data transmission, the device comprising: a transmitter, configured to simultaneously send data to at least two stations;

11. The apparatus of claim 10, wherein the second station is a phase shift keying modulated station.

The device according to claim 10 or 11, wherein if there are a plurality of the second sites, the processor is specifically configured to:

Adjusting, according to a percentage preset for each second station, a portion corresponding to a power percentage of data for transmitting the first site to transmit data of each of the second stations, and notifying the transmitter, wherein The sum of the percentages preset for each of the second stations is equal to 100%; the sender is configured to send the data of the second station after receiving the notification of the processor.

The device according to claim 10 or 11, wherein the second site has Multiple, the device further includes: a second processor: configured to: when the data of the at least one second site is sent, if there is still a third station in the remaining second site that has not been sent, the data is sent The power of the data of the second station is adjusted to transmit data of the third station, and the transmitter is notified.

The device according to claim 13, wherein, if there are multiple third sites, the second processor is specifically configured to: according to a percentage preset for each third site, Means for transmitting a corresponding percentage of the power of the data of the second station to transmit data of each of the third stations, and notifying the sender, wherein the preset for each of the third stations The sum of the percentages is equal to 100%.