WO2014183424A1

WO2014183424A1 - Method and device for selecting antenna

Info

Publication number: WO2014183424A1
Application number: PCT/CN2013/088712
Authority: WO
Inventors: 王力
Original assignee: 华为技术有限公司
Priority date: 2013-05-14
Filing date: 2013-12-06
Publication date: 2014-11-20
Also published as: CN104158579A

Abstract

Disclosed are a method and device for selecting an antenna, relating to the technical field of wireless communications and solving the problem in the prior art that subcarriers cannot be received correctly caused by the fact that a receiving end cannot accurately conduct channel estimation after receiving the subcarriers because adjacent subcarriers may come from different transmission antennas. The method comprises: acquiring the channel information about each subcarrier, determining a transmission antenna corresponding to a transceiving antenna pair having the optimal performance index in the transceiving antenna pairs of each of the subcarriers as a target transmission antenna in accordance with the channel information about each of the subcarriers, dividing subcarriers, which have the same target transmission antenna and are adjacent, into a subcarrier block, and including a pilot symbol in the subcarrier block, so as to transmit the corresponding subcarrier block which carries a pilot signal through the target transmission antenna. The embodiments of the present invention are applied to the processing procedure of antenna selection.

Description

The present invention claims the priority of the Chinese patent application filed on May 14, 2013, the Chinese Patent Application No. 201310177782.1, entitled "A Method and Apparatus for Antenna Selection", which The entire contents are incorporated herein by reference. TECHNICAL FIELD The present invention relates to the field of wireless communication technologies, and in particular, to a method and an apparatus for antenna selection.

BACKGROUND OF THE INVENTION Existing WLAN (Wireless Local Area Networks) technologies have been widely used in homes, campuses, hotels, corporate offices, etc. due to their wireless transmission, high-speed access, and low cost.

At present, there is a further requirement for WLAN, and the requirement of covering 1 km is proposed. When applied in an outdoor scenario, multipath delay spread is inevitable, and the channel quality in the bandwidth is no longer similar, and the difference between the good and the bad is very different. . In order to solve this problem, it is based on

MIMO (Mult i- input Multi-output) -0FDM ( Orthogonal

The frequency selection of the WIFI (Wireless Fidelity) system of Frequency Division Multiplexing (OFDM) is configured for each subcarrier of each antenna in MIMO, so that the advantage of antenna selection can be maximized.

In the process of implementing the present invention, the inventors have found that at least the following problems exist in the prior art: Since adjacent subcarriers may come from different transmitting antennas, the receiving end cannot accurately perform channel estimation after receiving the subcarriers, resulting in failure to Receive subcarriers correctly.

SUMMARY OF THE INVENTION Embodiments of the present invention provide a method and apparatus for antenna selection, which improves each sub- Channel estimation performance of the carrier.

In order to achieve the above object, the embodiment of the present invention adopts the following technical solutions:

In a first aspect, the present invention provides a method for antenna selection, including:

Obtaining channel information of each subcarrier, where the channel information is a signal strength received by each of the subcarriers on a channel between different pairs of transceiver antennas;

Determining, according to the channel information of each subcarrier, the transmit and receive antennas of the transmit and receive antenna pairs of each of the subcarriers are corresponding to the transmit antennas, and the target transmit antennas are used to transmit the corresponding subcarriers. ;

And dividing a target transmit antenna with the same and adjacent subcarriers into one subcarrier block, and including one pilot symbol in the subcarrier block, so as to transmit a corresponding pilot symbol carrying subcarrier through the target transmit antenna Piece.

In a first possible implementation manner of the first aspect, the determining, according to the channel information of each subcarrier, determining, that the transmitting antenna of the transmitting and receiving antenna pair with the best performance index of each of the subcarriers is corresponding to the transmitting antenna Target transmit antennas include:

Calculating, according to the maximum ratio combining, the first equivalent channel information of each of the subcarriers, where the first equivalent channel information is equivalent channel information between each of the transmitting antennas and the different receiving antennas;

A transmitting antenna corresponding to a maximum value among the first equivalent channel information is determined as a target transmitting antenna.

In a second possible implementation manner of the first aspect, the determining, according to the channel information of each subcarrier, determining, that the transmit and receive antenna pairs of the transmit and receive antenna pairs of each of the subcarriers are the corresponding transmit antennas Target transmit antennas include:

Calculating a signal to noise ratio of a channel between each of the transmitting antennas and the different receiving antennas of each of the subcarriers;

The maximum value of the signal to noise ratio is used as a performance indicator of the corresponding transmit antenna; and the transmit antenna corresponding to the maximum value of the performance indicator is determined as the target transmit antenna. Combining the first possible implementation of the first aspect or the second possible implementation In the third possible implementation manner, when the terminal is the receiving end, the acquiring channel information of each subcarrier includes:

Receiving a data frame sent by the transmitting end, where the data frame includes a pilot signal of each subcarrier;

Determining channel information of each subcarrier according to the pilot signal.

In conjunction with the third possible implementation of the first aspect, in a fourth possible implementation, the method includes:

And sending, by the sending end, the first feedback message carrying the indication information, where the indication information is used to indicate the division of the subcarrier block, and the transmitting end sends the target transmit antenna of each subcarrier block.

With reference to the first possible implementation manner of the first aspect, or the second possible implementation manner, in the fifth possible implementation manner, when the terminal is the sending end, the acquiring channel information of each subcarrier includes:

Obtaining a second feedback message sent by the receiving end, and acquiring channel information of each subcarrier from the second feedback message.

In conjunction with the fifth possible implementation of the first aspect, in a sixth possible implementation, the method further includes:

Sending a third feedback message to the receiving end, where the third feedback message includes receiving antenna indication information, and is used to notify the receiving end to receive the designated receiving antenna of each subcarrier block.

With reference to the fourth possible implementation manner of the first aspect, or the sixth possible implementation manner, in a seventh possible implementation manner, the performance indicator is a signal strength or a signal-to-noise ratio of a channel between a pair of transceiver antennas . In a second aspect, the present invention provides a terminal, including:

An acquiring unit, configured to acquire channel information of each subcarrier, where the channel information is a signal strength received by each of the subcarriers on a channel between different pairs of transmitting and receiving antennas; a first processing unit, configured to determine, according to the channel information of each subcarrier, that the transmit and receive antennas with the best performance indicators of the transmit and receive antenna pairs of each of the subcarriers are the target transmit antennas, and the target transmit antennas Used to transmit corresponding subcarriers;

a second processing unit, configured to divide a target transmit antenna with the same and adjacent subcarriers into one subcarrier block, and include a pilot symbol in the subcarrier block, so as to transmit a corresponding carryover by using the target transmit antenna A subcarrier block with pilot symbols.

In a first possible implementation manner of the second aspect, the first processing unit includes: a first processing module, configured to calculate, according to a maximum ratio combining, first equivalent channel information of each subcarrier, where An equivalent channel information is equivalent channel information between each transmitting antenna and a different receiving antenna;

And a second processing module, configured to determine, as the target transmit antenna, a transmit antenna corresponding to a maximum value among the first equivalent channel information.

In a second possible implementation manner of the second aspect, the first processing unit includes: a third processing module, configured to calculate a channel of each of the transmit antennas and the different receive antennas of each of the subcarriers Noise ratio

a fourth processing module, configured to use a maximum value of the signal to noise ratio as a performance indicator of the corresponding transmit antenna;

And a fifth processing module, configured to determine, as the target transmit antenna, a transmit antenna corresponding to the maximum value of the performance indicators.

With reference to the first possible implementation manner of the second aspect, or the second possible implementation manner, in a third possible implementation manner, when the terminal is a receiving end, the acquiring unit includes:

a receiving module, configured to receive a data frame sent by the sending end, where the data frame includes a pilot signal of each subcarrier;

And a determining module, configured to determine channel information of each of the subcarriers according to the pilot signal.

Combining the third possible implementation of the second aspect, in the fourth possible implementation Wherein, the terminal further includes:

a first sending unit, configured to send, to the sending end, a first feedback message that carries the indication information, where the indication information is used to indicate the division of the subcarrier block, and the sending end sends the each subcarrier The target transmit antenna of the block.

With reference to the first possible implementation manner of the second aspect, or the second possible implementation manner, in a fifth possible implementation manner, when the terminal is a sending end, the acquiring unit is specifically configured to acquire and receive Sending a second feedback message, and acquiring channel information of each subcarrier from the second feedback message.

In conjunction with the fifth possible implementation of the second aspect, in a sixth possible implementation, the terminal further includes:

The second sending unit is configured to send a third feedback message to the receiving end, where the third feedback message includes receiving antenna indication information, and is used to notify the receiving end to receive the designated receiving antenna of each subcarrier block.

With reference to the fourth possible implementation manner of the second aspect, or the sixth possible implementation manner, in a seventh possible implementation manner, the performance indicator in the first processing unit is between a pair of transceiver antennas The signal strength or signal to noise ratio of the channel.

A method and apparatus for antenna selection according to an embodiment of the present invention, by acquiring channel information of each subcarrier, where the channel information is a signal strength received by each subcarrier on a channel between different pairs of transceiver antennas, and Determining, according to the channel information of each subcarrier, the transmit and receive antennas of the transmit and receive antenna pairs of each of the subcarriers are corresponding to the transmit antennas, and the target transmit antennas are used to transmit the corresponding subcarriers. And then dividing the target transmit antennas into the same and adjacent subcarriers into one subcarrier block, and including a pilot symbol in the subcarrier block, so as to transmit corresponding pilot symbols carried by the target transmit antenna Subcarrier block. The embodiment of the present invention solves the problem that the adjacent subcarriers may be from different transmitting antennas in the prior art, and the receiving end cannot accurately perform channel estimation after receiving the subcarriers, thereby failing to correctly receive the subcarriers, and improving each Channel estimation performance of subcarriers. 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 of the present invention will be briefly described below. Obviously, the drawings described below are only some implementations of the present invention. For example, other drawings may be obtained from those of ordinary skill in the art in light of the inventive work.

FIG. 1 is a flowchart of a method for antenna selection according to an embodiment of the present invention; FIG. 2 is a flowchart of another method for antenna selection according to an embodiment of the present invention; A flowchart of a method for selecting an antenna; FIG. 4 is a structural diagram of a terminal according to an embodiment of the present invention;

FIG. 5 is a structural diagram of a first processing unit in a terminal according to an embodiment of the present invention; FIG. 6 is a structural diagram of another first processing unit in a terminal according to an embodiment of the present disclosure;

FIG. 7 is a structural diagram of an acquiring unit in a terminal according to an embodiment of the present invention; FIG. 8 is a structural diagram of another terminal according to an embodiment of the present invention;

FIG. 9 is a structural diagram of still another terminal according to an embodiment of the present invention;

FIG. 10 is a structural diagram of a terminal 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 only a part of the embodiments of the present invention, and not all of the embodiments. example. All other embodiments obtained by a person skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

As shown in FIG. 1, an embodiment of the present invention provides a method for antenna selection, including the following steps: 1 01. Obtain channel information of each subcarrier, where the channel information is a signal strength received by each subcarrier on a channel between different pairs of transceiver antennas;

And determining, according to the channel information of each subcarrier, that the transmit and receive antennas with the best performance indicators of the transmit and receive antennas of each of the subcarriers are the target transmit antennas, and the target transmit antennas are used for transmitting the corresponding antennas. Subcarrier

1 03. Divide a target transmit antenna with the same and adjacent subcarriers into one subcarrier block, and include a pilot symbol in the subcarrier block, so as to transmit a corresponding pilot symbol carried by the target transmit antenna. Subcarrier block.

An embodiment of the present invention provides a method for selecting an antenna, by acquiring channel information of each subcarrier, where the channel information is a signal strength received by each subcarrier on a channel between different pairs of transmitting and receiving antennas, and according to the Channel information of each subcarrier, determining that the transmit and receive antennas of the transmit and receive antenna pairs of each of the subcarriers have the same transmit antenna as the target transmit antenna, and the target transmit antenna is configured to transmit the corresponding subcarrier, and then The target transmit antennas are the same and the adjacent subcarriers are divided into one subcarrier block, and a pilot symbol is included in the subcarrier block, so that the corresponding subcarrier block carrying the pilot symbol is transmitted by the target transmit antenna. . The embodiment of the present invention solves the problem that the adjacent subcarriers may be from different transmitting antennas in the prior art, and the receiving end cannot accurately perform channel estimation after receiving the subcarriers, thereby failing to correctly receive the subcarriers, and improving each Channel estimation performance of subcarriers.

In an implementation manner of the embodiment of the present invention, a method for selecting an antenna is provided. As shown in FIG. 2, the method includes the following steps:

201. The receiving end receives a data frame sent by the sending end, where the data frame includes a pilot signal of each subcarrier.

202. Determine channel information of each subcarrier according to the pilot signal.

The pilot signal is described by using an LTF (Long Training Training Sequence) as an example. The data frame may be an NDP (Null Data Packet) or a normal data frame. Where the NDP includes each of the transmit antennas The training sequence, LTF 1 . . . LTFN , obtains channel information between the receiving antenna and the transmitting antenna through channel estimation. When the data frame is a normal frame, the channel information of the receiving antenna to the transmitting antenna may be estimated according to the LTF in the preamble of the normal frame, or estimated according to the LTF 1. . . LTFN in the preamble of the normal frame. Receive channel information from the antenna to the transmit antenna.

According to formula (1), the signal strength received by each subcarrier on the channel between different pairs of transmitting and receiving antennas can be obtained:

y = Hx + N formula

( 1 )

Where y represents the signal received by the receiving end on one subcarrier, X represents the signal transmitted by the transmitting end, that is, the LTF information, and according to the protocol, X is known to the receiving end, and N represents noise, H is an m*n channel matrix, where m denotes m transmit antennas, n denotes n receive antennas, and the magnitude of the value in the matrix represents the signal strength received by the receive end.

Since the receiving end knows X and receives y, the matrix H can be estimated and the received signal strength on the channel between each pair of transmitting and receiving antennas is obtained.

For example, ^ denotes channel information from the ith receive antenna to the jth transmit antenna on the kth subcarrier.

2, according to the channel information of each subcarrier, determining that the transmit and receive antennas with the best performance indicators of the transmit and receive antenna pairs of each subcarrier are the target transmit antennas, so as to be sent on the target transmit antennas. Corresponding subcarriers.

The performance indicator is a signal strength or a signal-to-noise ratio of a channel between the pair of transmitting and receiving antennas, and the target transmitting antenna can be determined by the following two methods.

method one,

Determining, as the target transmission, a transmitting antenna corresponding to a maximum value among the first equivalent channel information Shoot the antenna.

Assuming that the channel information between a transmitting antenna and n receiving antennas is hh ₂ ... h _n , h* represents the conjugate of h, then between the transmitting antenna 1 and the n receiving antennas is obtained according to the formula ( 2 ) First equivalent channel information:

H" ² = * +h ₂ * h ₂ * +... h _n * h _n * formula

( 2 )

Wherein, |3⁄4| ² represents the first equivalent channel information between the transmitting antenna 1 and the n receiving antennas. According to the formula (2), all the first equivalent channel information corresponding to the m transmitting antennas can be obtained|^| ² machines| ² ...| | ² .

Finding a maximum value |Hj | ² from the first equivalent channel information | | ² , |H ₂ | ² ... |H _m | ² , and the transmitting antenna corresponding to the maximum value |Hj| ^{2 is} Target transmit antenna.

Method 2,

The maximum value of the signal to noise ratio is used as a performance indicator of the corresponding transmit antenna; and the transmit antenna corresponding to the maximum value of the performance indicator is determined as the target transmit antenna. Suppose that the channel information between a transmitting antenna and n receiving antennas is hp h ₂ ... h _n , h* represents the conjugate of h, and since the noise is the same, then one transmitting antenna and n receiving antennas The signal-to-noise ratio of the channel between them is ^ίΝ, h ₂ *h ₂ */N...h _n *h _n */N , and the maximum value hj*h /N in the signal-to-noise ratio is used as transmit antenna performance, the performance index _m to give the corresponding transmit antennas, selecting the maximum performance index from the performance metrics m, the maximum value of the performance index corresponding to the transmit antenna determines a target transmit antenna.

204. The receiving end divides the target transmit antenna into the same sub-carrier and divides the sub-carrier into one sub-carrier block, and includes a pilot symbol in the sub-carrier block, so that the target transmit antenna transmits the corresponding carry A subcarrier block of pilot symbols.

According to the channel coherence bandwidth, the same and adjacent subcarriers of the target transmit antenna are divided into One subcarrier block, and including one pilot symbol in the subcarrier block. For example, assuming that the channel coherence bandwidth is the frequency width of 14 OFDM subcarriers, there are 56 subcarriers for transmission, which are divided into 4 subcarrier blocks, namely 1-14, 15-28, 29-42, 43-56. The antenna selection of each subcarrier block is the same, and one pilot symbol is included in the subcarrier block.

205. The receiving end sends a feedback message carrying the indication information to the sending end, where the indication information is used to indicate the division of the subcarrier block, and the sending end sends the target of each subcarrier block. Transmitting antenna.

In addition to the indication indicating the division of the subcarrier block, and the indication information of the target transmitting antenna of each subcarrier block sent by the transmitting end, the feedback message itself carries the feedback message in the prior art. Feedback information.

206. The sending end receives a feedback message that is sent by the receiving end and carries the indication information.

207. The sending end sends, according to the received feedback information, a target transmit antenna that is indicated by the sub-carrier block in the indication information.

For example, taking a 2 MHz bandwidth system of 2 rounds and 2s as an example, after receiving the data frame sent by the transmitting end, the receiving end acquires channel information of each subcarrier from the data frame, for example, ^ indicates Channel information of the i-th receive antenna to the j-th transmit antenna on the kth subcarrier. The receiving end adopts a maximum ratio combining manner, and the first equivalent channel information between the same transmitting antenna and the two receiving antennas is | | ² = | | ² , and different transmitting and receiving antenna pairs are selected on the kth subcarrier. The equation with the largest signal strength can be expressed as max(|H | ² , |HJ | ² , (|H + H ₂ ^k 1 ² / 2)) , where |H| ² represents the kth subcarrier at two receiving antennas The signal strength on the equivalent channel to the first transmit antenna, |H ₂ f represents the signal strength of the kth subcarrier on the equivalent channel of the two receive antennas to the second transmit antenna, (|H + H ₂ f/2) represents the signal strength of the kth subcarrier on the equivalent channel of the two receiving antennas to the first transmitting antenna, and the mean of the signal strengths of the equivalent channels of the two receiving antennas to the second transmitting antenna , select the transmitting day of the transmitting and receiving antenna pair with the highest signal strength The line serves as the target transmit antenna for the kth subcarrier.

In addition, according to the channel coherence bandwidth, the adjacent subcarriers are divided into one subcarrier block, and each subcarrier block needs 2 bits to indicate the transmission condition of the target transmitting antenna. For example, 10 indicates that the first transmitting antenna transmits, and 01 indicates the second. The root transmit antenna transmits, and 11 indicates that the first and second transmit antennas are simultaneously transmitted. When there are 52 subcarriers in 802.llah at 2MHz, a 52bit bitmap is required to represent the subcarrier allocation, so 104bit is needed to indicate the subcarrier transmission. When 52 subcarriers are divided into four subcarrier blocks, and each subcarrier block includes 13 consecutive subcarriers, 8 bits are used to indicate the transmission condition of the target transmission antennas of the four subcarrier blocks.

Optionally, each subcarrier block can simultaneously indicate the transmission condition of the target transmit antenna and the reception condition of the receive antenna through 4 bits. When there are 52 subcarriers, 208 bits are needed to indicate the reception and transmission of the subcarrier. When 52 subcarriers are divided into four subcarrier blocks, and each subcarrier block includes 13 consecutive subcarriers, 16 bits are used to indicate the reception and transmission of 4 subcarrier blocks.

The foregoing allocation information is carried in the indication information in the feedback message sent by the receiving end to the sending end. In addition, the sub-carrier block may be included in the feedback message.

The above feedback message may include CSI (channel state information) frame, ACK (Acknowledgement) frame, block ACK (block acknowledgment) frame, short ACK (short acknowledgment) frame, short block (short block) frame, Or other frames, etc.

The physical layer bearer position of the feedback message may be a data field of an ACK frame, or a data field of a block ACK frame, or a short ACK frame. Signal field (SIG field), or signal block (SIG field) of short block ACK frame, MAC (Media Access Control) control, MAC management, normal data frame Data fields and/or signal domains, etc. After the sending end receives the feedback message sent by the receiving end, the sending end sends each subcarrier block according to the target transmitting antenna indicated in the indication information carried in the feedback message.

Included in the subcarrier block, a pilot symbol, so that the receiving end can perform channel correction of the subcarrier block when receiving the subcarrier block carrying the pilot symbol, and correctly acquire the subcarrier block. . When adjacent subcarrier blocks are from the same target transmit antenna, joint interpolation can be considered. When the position of the pilot symbol changes periodically with time, only the pilot symbols in the contiguous subcarrier block from the same target transmit antenna are corrected, if there is no contiguous subcarrier block in the same target transmit antenna In the case of the pilot symbols, the channel estimation correction is performed using the pilot symbols in the previous subcarrier block.

In another implementation manner of the embodiment of the present invention, a method for antenna selection is provided. As shown in FIG. 3, the method includes the following steps:

301. The receiving end receives a data frame sent by the sending end, where the data frame includes a pilot signal of each subcarrier.

302. The receiving end determines channel information of each subcarrier according to the pilot signal.

The pilot signal is described by using an LTF (Long Training Field) as an example. The data frame may be an NDP (Null Data Packet) or a normal data frame, where the NDP includes The training sequence corresponding to each transmitting antenna, LTF1...LTFN, obtains channel information between the receiving antenna and the transmitting antenna through channel estimation. When the data frame is a normal frame, channel information of the receiving antenna to the transmitting antenna may be estimated according to the LTF in the preamble of the normal frame, or estimated according to LTF 1... LTFN in the preamble of the normal frame. Receive channel information from the antenna to the transmit antenna.

According to the formula (1), the signal strength received by each subcarrier on the channel between different pairs of transmitting and receiving antennas can be obtained.

For example, ^ denotes channel information of the ith receive antenna to the jth transmit antenna on the kth subcarrier. 303. The receiving end sends a feedback message to the sending end, where the feedback message carries channel information of each subcarrier.

304. The sending end acquires a feedback message sent by the receiving end, and acquires channel information of each subcarrier from the feedback message.

305. Determine, according to the channel information of each subcarrier, that the transmit and receive antennas with the best performance indicators of the transmit and receive antenna pairs of each of the subcarriers are the target transmit antennas, and the target transmit antennas are used to transmit corresponding Subcarrier.

For the specific manner of determining the target transmitting antenna, refer to the two methods in step 2 03, and details are not described herein again.

306. Send a third feedback message to the receiving end, where the third feedback message includes receiving antenna indication information, and is used to notify the receiving end to receive the designated receiving antenna of each subcarrier block.

In this embodiment, the target transmitting antenna is specified by the transmitting end, and the receiving end does not determine a receiving antenna for receiving the subcarrier block transmitted by the target transmitting antenna, so it is determined by the transmitting end. Specify the receiving antenna.

For determining the receiving antenna, refer to the two methods described in step 203;

method one

Calculating, according to the maximum ratio combining, the second equivalent channel information of each of the subcarriers, where the second equivalent channel information is equivalent channel information between each receiving antenna and a different transmitting antenna;

A receiving antenna corresponding to a maximum value among the second equivalent channel information is determined as a designated receiving antenna.

Suppose that the channel information between a receiving antenna and m transmitting antennas is h, h ₂ ' . . . h _m ', h'* denotes the conjugate of h', and the receiving antenna 1 is obtained according to formula (3). Second equivalent channel information between m transmit antennas:

* hj +h ₂ * h +...h— * h„ Equation ( 2 ) Indicates second equivalent channel information between the receiving antenna 1 and the m transmitting antennas. According to formula (3), all second equivalent channel information corresponding to n receiving antennas can be obtained.

Finding a maximum value from the second equivalent channel information, the maximum value corresponding to the receiving antenna is a designated receiving antenna

Method 2,

Calculating a signal to noise ratio of a channel between each of the receiving antennas and the different transmitting antennas of each of the subcarriers;

The maximum value of the signal to noise ratio is used as a performance indicator of the corresponding receiving antenna; and the receiving antenna corresponding to the maximum value of the performance indicator is determined as the designated receiving antenna. Suppose that the channel information between a receiving antenna and m transmitting antennas is h, h ₂ ' ... h _m ', h'* represents the conjugate of h', and since the noise is the same, a receiving antenna The signal-to-noise ratio of the channel with the m-th transmitting antenna is 11», h ₂ ' *h ₂ '*/N...h _m ' *h _m '*/N , which is the largest of the signal-to-noise ratios The value h/*h/*/N is used as the performance index of the receiving antenna, and the corresponding performance index of the n receiving antennas is obtained, and the largest performance indicator is selected from the n performance indicators, where the performance indicator is The receiving antenna corresponding to the maximum value is determined to be the designated receiving antenna.

307. The receiving end receives a third feedback message sent by the sending end.

And receiving, according to the specified receiving antenna in the third feedback message, a subcarrier block sent by the transmitting end. And a subcarrier block, and including a pilot symbol in the subcarrier block, to transmit a corresponding subcarrier block carrying a pilot symbol through the target transmit antenna.

According to the channel coherence bandwidth, the adjacent subcarriers are divided into one subcarrier block, and the subcarrier block includes a pilot symbol, so that the receiving end can receive the subcarrier block carrying the pilot symbol when receiving Performing channel correction of the subcarrier block to correctly acquire the subcarrier block. For example, taking the 2Mhz bandwidth system of 2 rounds and 2s as an example, after receiving the data frame sent by the sending end, the receiving end acquires channel information of each subcarrier from the data frame, for example, ^ indicates Channel information of the i-th receive antenna to the j-th transmit antenna on the kth subcarrier. The receiving end carries the channel information of each subcarrier in a feedback message and sends the information to the sending end.

After obtaining the channel information of each subcarrier, the transmitting end uses the maximum ratio combining manner to equalize the channel of the two receiving antennas to the same transmitting antenna as one channel, that is, l ² :! ^^^ ² ' Selecting the common signal strength of the pair of different transmitting and receiving antennas on the ^kth subcarrier can be expressed as max(|H| ² , |H| ² , (|H + H ₂ †/2)), where |H ² represents the signal strength of the kth subcarrier on the equivalent channel of the two receiving antennas to the first transmitting antenna, and | ² represents the equivalent channel of the kth subcarrier from the two receiving antennas to the second transmitting antenna. The signal strength above, (|H + H ₂ f /2) represents the signal strength of the kth subcarrier on the equivalent channel of the two receiving antennas to the first transmitting antenna, and the two receiving antennas to the

The average of the signal strengths on the equivalent channels of the two transmitting antennas is selected as the target transmitting antenna of the kth subcarrier of the transmitting antenna pair having the largest signal strength.

According to the channel coherence bandwidth, the adjacent subcarriers are divided into one subcarrier block, and each subcarrier block needs 2 bits to indicate the reception condition of the receiving antenna. For example, 10 indicates the first receiving antenna reception, and 01 indicates the second receiving antenna. Receiving, 11 indicates that the first and second receiving antennas are simultaneously received. When there are 52 subcarriers in 802.llah at 2MHz, a 52bit bitmap is required to indicate subcarrier allocation, so 104bit is needed to indicate the reception of subcarriers. When 52 subcarriers are divided into four subcarrier blocks, and each subcarrier block includes 13 consecutive subcarriers, 8bit is used to indicate the reception condition of the receiving antennas of the four subcarrier blocks, thereby saving feedback overhead.

When the receiving end is based on the channel information calculated by the NDP sent by the transmitting end, the feedback message is a CSI frame according to the existing NDP measurement feedback process.

When the receiving end performs the channel information calculation according to the normal frame sent by the sending end, the channel information needs to carry the channel information in the feedback message corresponding to the normal frame. The above feedback message may include a CSI frame, an ACK frame, a block ACK frame, a short ACK frame, a short block frame, or other frames.

The physical layer bearer position of the feedback message may be a data field of an ACK frame, or a data field of a block ACK frame, or a short ACK frame. The signal field (SIG field), or the signal field (SIG field) of the short block ACK frame, the MAC control frame, the MAC management frame, the data field of the normal data frame, and/or the signal domain.

Transmitting in a subcarrier block, the subcarrier block includes a pilot symbol, so that the receiving end can perform channel correction of the subcarrier block when receiving the subcarrier block carrying the pilot symbol. The subcarrier block is correctly acquired. Joint interpolation can be considered when adjacent subcarrier blocks are from the same target transmit antenna. When the position of the pilot symbol changes periodically with time, only the pilot symbols in the contiguous subcarrier block from the same target transmit antenna are corrected, if there is no contiguous subcarrier block in the same target transmit antenna In the case of the pilot symbols, the channel estimates are corrected using the pilot symbols in the previous subcarrier block.

Through the foregoing implementation manner, the channel quality is better, the higher the received signal power is, and the channel estimation performance of each subcarrier is improved without increasing the transmission power. The embodiment of the present invention provides a terminal 40. As shown in FIG. 4, the terminal 40 includes an obtaining unit 41, a first processing unit 42, and a second processing unit 43.

The acquiring unit 41 is configured to acquire channel information of each subcarrier, where the channel information is a signal strength received by each subcarrier on a channel between different pairs of transmitting and receiving antennas, and a first processing unit 42 Channel information of each subcarrier, determining that the transmit and receive antennas of the transmit and receive antenna pairs of each of the subcarriers have the same transmit antenna as the target transmit antenna, and the target transmit antenna is configured to transmit the corresponding subcarrier; The processing unit 43 is configured to divide the target transmit antennas into the same and adjacent subcarriers into one subcarrier block, and include a pilot symbol in the subcarrier block, so as to pass The target transmit antenna transmits a corresponding subcarrier block carrying a pilot symbol. An embodiment of the present invention provides a terminal, by acquiring channel information of each subcarrier, where the channel information is a signal strength received by each subcarrier on a channel between different pairs of transceiver antennas, and according to each subcarrier Channel information, determining that the transmit and receive antennas of the transmit and receive antenna pairs of each of the subcarriers have the best transmit and receive antennas as the target transmit antennas, and the target transmit antennas are used to transmit corresponding subcarriers, and then the target transmit antennas The same and adjacent subcarriers are divided into one subcarrier block, and one pilot symbol is included in the subcarrier block to transmit a corresponding subcarrier block carrying pilot symbols through the target transmit antenna. The embodiment of the present invention solves the problem that the adjacent subcarriers may be from different transmitting antennas in the prior art, and the receiving end cannot accurately perform channel estimation after receiving the subcarriers, thereby failing to correctly receive the subcarriers, and improving each Channel estimation performance of subcarriers.

Optionally, as shown in FIG. 5, the first processing unit 42 includes:

a first processing module 51, configured to calculate first equivalent channel information of each subcarrier according to maximum ratio combining, where the first equivalent channel information is equivalent channel information between each transmitting antenna and different receiving antennas ;

The second processing module 52 is configured to determine, as the target transmit antenna, a transmit antenna corresponding to a maximum value among the first equivalent channel information.

Optionally, as shown in FIG. 6, the first processing unit 42 includes:

The third processing module 61 is configured to calculate a signal to noise ratio of a channel between each of the transmit antennas and the different receive antennas of each of the subcarriers;

a fourth processing module 62, configured to use a maximum value of the signal to noise ratio as a performance indicator of the corresponding transmitting antenna;

The fifth processing module 63 is configured to determine, as the target transmit antenna, a transmit antenna corresponding to a maximum value among the performance indicators.

Optionally, when the terminal is a receiving end, as shown in FIG. 7, the acquiring unit 41 includes: The receiving module 71 is configured to receive a data frame sent by the sending end, where the data frame includes a pilot signal of each subcarrier;

The determining module 72 is configured to determine channel information of each subcarrier according to the pilot signal.

Optionally, as shown in FIG. 8, the terminal further includes:

The first sending unit 44 is configured to send a first feedback message carrying the indication information to the sending end, where the indication information is used to indicate the division of the subcarrier block, and the sending end sends the each sub The target transmit antenna of the carrier block.

Optionally, when the terminal is a sending end, the acquiring unit is specifically configured to acquire a second feedback message sent by the receiving end, and obtain channel information of each subcarrier from the second feedback message.

Optionally, as shown in FIG. 9, the terminal further includes:

The second sending unit 45 is configured to send a third feedback message to the receiving end, where the third feedback message includes receiving antenna indication information, and is used to notify the receiving end to receive the designated receiving antenna of each subcarrier block. .

For the operation process of the terminal 40, refer to the processing procedure of the above antenna selection method. The embodiment of the present invention provides a terminal. As shown in FIG. 10, the terminal 10 includes a memory 1 001, a transceiver 1 002, and a processor 1 003.

The memory 1 001 is configured to store instruction and channel information;

The transceiver 1 002 is configured to receive or send channel information, and the feedback message. The processor 1 003 is configured to execute the instruction in the memory 1 001, where: performing: acquiring channel information of each subcarrier, where the channel information is The signal strength received by each subcarrier on a channel between different pairs of transceiver antennas;

Determining, according to the channel information of each subcarrier, the transmit and receive antennas of the transmit and receive antenna pairs of each of the subcarriers are corresponding to the transmit antennas, and the target transmit antennas are used to transmit the corresponding subcarriers. ; And dividing a target transmit antenna with the same and adjacent subcarriers into one subcarrier block, and including one pilot symbol in the subcarrier block, so as to transmit a corresponding pilot symbol carrying subcarrier through the target transmit antenna Piece.

An embodiment of the present invention provides a terminal, by acquiring channel information of each subcarrier, where the channel information is a signal strength received by each subcarrier on a channel between different pairs of transceiver antennas, and according to each subcarrier Channel information, determining that the transmit and receive antennas of the transmit and receive antenna pairs of each of the subcarriers have the best transmit and receive antennas as the target transmit antennas, and the target transmit antennas are used to transmit corresponding subcarriers, and then the target transmit antennas The same and adjacent subcarriers are divided into one subcarrier block, and one pilot symbol is included in the subcarrier block to transmit a corresponding subcarrier block carrying pilot symbols through the target transmit antenna. The embodiment of the present invention solves the problem that the adjacent subcarriers may be from different transmitting antennas in the prior art, and the receiving end cannot accurately perform channel estimation after receiving the subcarriers, thereby failing to correctly receive the subcarriers, and improving each Channel estimation performance of subcarriers.

Optionally, the processor 1 003 is further configured to:

The maximum value of the signal to noise ratio is used as a performance indicator of the corresponding transmit antenna; and the transmit antenna corresponding to the maximum value of the performance indicator is determined as the target transmit antenna. Optionally, when the terminal is the receiving end, the processor 1 003 is further configured to: receive, by using the transceiver 1 002, a data frame sent by the sending end, where the data frame is included in the data frame a pilot signal for each subcarrier;

Optionally, the processor 1 003 is further configured to:

Sending, by the transceiver 1 002, a first feedback message carrying the indication information to the sending end, where the indication information is used to indicate the division of the subcarrier block, and the sending end sends the each subcarrier The target transmit antenna of the block.

Optionally, when the terminal is a sending end, the processor 1 003 is further configured to: obtain, by using the transceiver 1 002, a second feedback message sent by the receiving end, and obtain the second feedback message from the second feedback message. Channel information for each subcarrier.

Optionally, the processor 1 003 is further configured to:

The third feedback message is sent to the receiving end by the transceiver 1 002, where the third feedback message includes receiving antenna indication information, and is used to notify the receiving end to receive the designated receiving antenna of each subcarrier block.

For the operation process of the terminal 10, refer to the processing procedure of the above antenna selection method. It will be apparent to those skilled in the art that, for convenience and brevity of description, only the division of each functional module described above is exemplified. In practical applications, the above-mentioned function assignment can be completed by different functional modules as needed. The internal structure of the device is divided into different functional modules to perform all or part of the functions described above. For the specific working process of the system, the device and the unit described above, reference may be made to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be used. 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, which may be Electrical, mechanical or other form.

The units described as separate components may or may not be physically separate. The components displayed as units may or may not be physical units, i.e., may be located in one place, or may be distributed over multiple network units. The purpose of the embodiment of the present embodiment can be achieved by selecting some or all of the units according to actual needs.

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 above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may contribute to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium. The instructions include a plurality of instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (p roce ss or ) to perform all or part of the steps of the method of various embodiments of the present invention. The foregoing storage medium includes: a USB flash drive, a mobile hard disk, a read only memory (ROM, Read-On y

Memory), random access memory (RAM, Random Acce s s Memory), disk or optical disc, and other media that can store program code.

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 appended claims.

Claims

Rights request

1. An antenna selection method, characterized by including:

Obtain the channel information of each subcarrier, where the channel information is the signal strength received by each subcarrier on the channel between different transceiver antenna pairs;

According to the channel information of each subcarrier, the transmitting antenna corresponding to the transceiver antenna pair with the best performance index among the transceiver antenna pairs of each subcarrier is determined to be the target transmitting antenna, and the target transmitting antenna is used to transmit the corresponding subcarrier. ;

Divide the same and adjacent subcarriers of the target transmitting antenna into a subcarrier block, and include a pilot symbol in the subcarrier block, so that the corresponding subcarrier carrying the pilot symbol is transmitted through the target transmitting antenna. piece.

2. The method of antenna selection according to claim 1, characterized in that, according to the channel information of each subcarrier, determining the corresponding transceiver antenna pair with the best performance index among the transceiver antenna pairs of each subcarrier. The transmitting antenna is the target transmitting antenna, including: calculating the first equivalent channel information of each subcarrier according to the maximum ratio combination, the first equivalent channel information being the equivalent channel between each transmitting antenna and different receiving antennas information;

The transmitting antenna corresponding to the maximum value in the first equivalent channel information is determined as the target transmitting antenna.

3. The method of antenna selection according to claim 1, characterized in that, according to the channel information of each subcarrier, determining the corresponding transceiver antenna pair with the optimal performance index among the transceiver antenna pairs of each subcarrier. The transmitting antenna is the target transmitting antenna including: calculating the signal-to-noise ratio of the channel between each transmitting antenna of each subcarrier and different receiving antennas;

The maximum value in the signal-to-noise ratio is used as the performance index of the corresponding transmitting antenna; and the transmitting antenna corresponding to the maximum value in the performance index is determined as the target transmitting antenna.

4. The method of antenna selection according to claim 2 or 3, characterized in that, when the terminal is a receiving end, the obtaining the channel information of each subcarrier includes: Receive a data frame sent by the transmitting end, where the data frame includes a pilot signal for each subcarrier;

According to the pilot signal, channel information of each subcarrier is determined.

5. The method of antenna selection according to claim 4, characterized in that the method includes:

A first feedback message carrying indication information is sent to the sending end, where the indication information is used to indicate the division of the subcarrier blocks, and the sending end sends the target transmitting antenna of each subcarrier block.

6. The antenna selection method according to claim 2 or 3, characterized in that when the terminal is the transmitting end, the obtaining the channel information of each subcarrier includes:

Obtain the second feedback message sent by the receiving end, and obtain the channel information of each subcarrier from the second feedback message.

7. The method of antenna selection according to claim 6, characterized in that the method further includes:

Send a third feedback message to the receiving end, where the third feedback message includes receiving antenna indication information, used to notify the receiving end of the designated receiving antenna for receiving each subcarrier block.

8. The antenna selection method according to claim 5 or 7, characterized in that the performance index is the signal strength or signal-to-noise ratio of the channel between the transmitting and receiving antenna pairs.

9. A terminal, characterized in that it includes:

An acquisition unit, configured to acquire channel information of each subcarrier, where the channel information is the signal strength received by each subcarrier on the channel between different transceiver antenna pairs;

The first processing unit is configured to determine, based on the channel information of each subcarrier, that the transmitting antenna corresponding to the transceiver antenna pair with the best performance index among the transceiver antenna pairs of each subcarrier is the target transmitting antenna, and the target transmitting antenna Used to transmit corresponding subcarriers;

The second processing unit is used to divide subcarriers with the same and adjacent target transmitting antennas into A subcarrier block, and a pilot symbol is included in the subcarrier block, so that the corresponding subcarrier block carrying the pilot symbol is transmitted through the target transmitting antenna.

10. The terminal according to claim 9, characterized in that the first processing unit includes:

A first processing module, configured to calculate the first equivalent channel information of each subcarrier according to the maximum ratio combination, where the first equivalent channel information is the equivalent channel information between each transmitting antenna and different receiving antennas;

The second processing module is configured to determine the transmitting antenna corresponding to the maximum value in the first equivalent channel information as the target transmitting antenna.

11. The terminal according to claim 9, characterized in that the first processing unit includes:

The third processing module is used to calculate the signal-to-noise ratio of the channel between each transmitting antenna and different receiving antennas of each subcarrier;

The fourth processing module is used to use the maximum value of the signal-to-noise ratio as the performance index of the corresponding transmitting antenna;

The fifth processing module is used to determine the transmitting antenna corresponding to the maximum value in the performance index as the target transmitting antenna.

12. The terminal according to claim 10 or 11, characterized in that when the terminal is a receiving end, the obtaining unit includes:

A receiving module, configured to receive a data frame sent by the transmitting end, where the data frame includes a pilot signal for each subcarrier;

A determining module, configured to determine the channel information of each subcarrier according to the pilot signal.

13. The terminal according to claim 12, characterized in that, the terminal further includes: a first sending unit, configured to send a first feedback message carrying indication information to the sending end, the indication The information is used to indicate the division of the subcarrier blocks, and the target transmitting antenna to which the transmitting end sends each subcarrier block.

14. The terminal according to claim 10 or 11, characterized in that, when the terminal is a sending end, the obtaining unit is specifically configured to obtain the second feedback message sent by the receiving end, and obtain the second feedback message from the second feedback message. The channel information of each subcarrier is obtained in the feedback message.

15. The terminal according to claim 14, characterized in that, the terminal further includes: a second sending unit, configured to send a third feedback message to the receiving end, and the third feedback message includes a receiving antenna indication. Information used to notify the receiving end of the designated receiving antenna for receiving each subcarrier block.

16. The terminal according to claim 13 or 15, characterized in that the performance index in the first processing unit is the signal strength or signal-to-noise ratio of the channel between the transmitting and receiving antenna pairs.