CN103002471B - A kind of method of channel detection, Apparatus and system - Google Patents

Abstract

A method, device, and system for channel detection provided by the embodiments of the present invention relate to the communication field, and are used to reduce the waiting time of receiving stations as much as possible without affecting the reception of feedback requests, thereby achieving the purpose of power saving . The channel detection method includes: sending an empty packet to notify the NDPA broadcast packet to notify all relevant receiving stations to prepare for detection; continuing to send an empty packet NDP broadcast packet so that after the relevant receiving stations receive the NDP broadcast packet, they can calculate their respective relative Channel feedback information; receive the channel feedback information sent by the receiving station corresponding to the first receiving station information carried in the NDPA broadcast packet; send to other receiving stations sequentially according to the sequence of station information in the NDPA broadcast packet from front to back A feedback request is used to receive channel feedback information sent by the other receiving stations, and this embodiment of the present invention is used for wireless communication.

Description

Method, device and system for channel detection

technical field

The present invention relates to the communication field, in particular to a method, device and system for channel detection.

Background technique

The wireless communication protocol Institute of Electrical and Electronics Engineers (Institute of Electrical and Electronics Engineers, referred to as IEEE) 802.11ac introduces a high throughput sounding mechanism (VHTSounding Protocol) that exists between the beamforming initiator (beamformer) and the beamforming receiver (beamformee). Channel detection mechanism. Through this mechanism, the beamforming initiator can better know the channel information between the beamforming receiver and the beamforming receiver, so as to improve the communication status by adjusting related parameters. The high-throughput rate detection mechanism is divided into the following two types according to its application scenarios: Multi-user multiple input multiple output mechanism (Multi-user multiple input multiple output, hereinafter abbreviated as MU-MIMO) and single user multiple input multiple output mechanism (Single-user multiple input multiple output, hereinafter abbreviated as SU-MIMO). Usually, for a network composed of a Basic Service Set (BSS for short), the physical device corresponding to the Beamformer is an access point (AccessPoint, which can be referred to as an AP), and the physical device corresponding to a Beamformee is a station (Station, which can be referred to as STA); for an ad hoc network that is not a basic service set, the physical device corresponding to the Beamformer can be a certain STA, and the physical device corresponding to the Beamformee can be other STAs.

A transmission opportunity (Transmitopportunity, TXOP for short) refers to a bounded time period in which a sending station obtains transmission of a specific traffic type through a competition mechanism of a contention period. Within a TXOP time limit, the successful sending station can monopolize the media resources and send single or multiple data frames to other stations. TXOP has a maximum time limit, and it can only be obtained by re-competition after it ends.

As shown in Figure 1, within the MU-MIMOTXOP time, the sending site will first send a Null Data Packet Announcement (hereinafter referred to as NDPA) broadcast packet to notify all relevant receiving sites to prepare for detection, and the related receiving sites shown in Figure 1 Taking 3 stations as an example, there may be 2 or more stations in practical applications; the frame format of the NDPA broadcast packet can refer to FIG. 2 . Next, the sending station will send a NullDataPacket (hereinafter referred to as NDP) broadcast packet, and all relevant receiving stations will calculate relevant channel feedback information for the received NDP broadcast packet, but after receiving the NDP broadcast packet, only when the receiving station The channel feedback information obtained by calculation can be immediately sent to the sending station only when the AID of the AID is equal to the AID in the first station information (STAInformation, hereinafter referred to as STAInfo) field of the previously received NDPA broadcast packet. For other receiving stations, they will immediately send the calculated channel feedback information to the sending station only when they respectively receive the beamforming report query (BeamformingRepotPoll) from the sending station. This channel feedback information is compressed by high-throughput beamforming The package (VHTCompressedBeamforming) feeds back the corresponding information.

In the process of channel detection mentioned above, during the entire TXOP time period, all receiving stations can only stay in the sleep state until the feedback is completed correctly or the entire TXOP time is consumed, otherwise the receiving station will enter the sleep state in advance and cannot receive correctly. Beamforming report requests and feedback correctly. Therefore, usually for MU-MIMO scenarios, except for the receiving station corresponding to the first STAInfo of the NDPA broadcast packet, which can give immediate feedback, the receiving station that other sent stations actively request to provide feedback information through the beamforming report is in a waiting state (that is, do not enter the sleep state) for a long time, which will cause a problem of high power consumption.

Contents of the invention

Embodiments of the present invention provide a method, device and system for channel detection, so as to achieve the purpose of reducing the waiting time of a receiving station and further saving power.

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

On the one hand, a method for channel detection is provided, including:

Send an empty packet to notify the NDPA broadcast packet to notify the relevant receiving stations to prepare for detection;

Continue to send an empty NDP broadcast packet, so that after the relevant receiving stations receive the NDP broadcast packet, they can calculate their respective channel feedback information;

receiving channel feedback information sent by a receiving station corresponding to the first station information carried in the NDPA broadcast packet;

Sending feedback requests to other receiving stations sequentially from front to back according to the station information arrangement sequence in the NDPA broadcast packet, so as to receive channel feedback information sent by the other receiving stations.

On the other hand, a method for channel detection is provided, including:

Receive the NDPA broadcast packet sent by the sending site and prepare for detection;

Receive the NDP broadcast packet sent by the sending site, and calculate the channel feedback information related to itself;

When going to sleep until the scheduled sleep time is reached, wake up yourself to receive the feedback request sent by the sending site;

After receiving the feedback request, send the channel feedback information to the sending station.

In one aspect, a site is provided, comprising:

The NDPA broadcast packet sending unit is used to send an empty packet to notify the NDPA broadcast packet to notify all relevant receiving stations to prepare for detection;

The NDP broadcast packet sending unit is used to continue to send an empty NDP broadcast packet, so that after the relevant receiving station receives the NDP broadcast packet, it calculates the respective relevant channel feedback information;

The first channel feedback information receiving unit is configured to receive the channel feedback information sent by the receiving station corresponding to the first station information carried in the NDPA broadcast packet;

The second channel feedback information receiving unit is configured to send feedback requests to other receiving stations sequentially from front to back according to the station information arrangement sequence in the NDPA broadcast packet, so as to receive the channel feedback information sent by the other receiving stations.

In another aspect, a site is provided that includes:

The NDPA broadcast packet receiving unit is used to receive the NDPA broadcast packet sent by the sending site and prepare for detection;

The NDP broadcast packet receiving unit is used to receive the NDP broadcast packet sent by the sending station, and calculate the channel feedback information related to itself;

The wake-up unit is used to wake up itself when going to sleep until the scheduled sleep time is reached, so as to receive the feedback request sent by the sending site;

A feedback information sending unit, configured to send the channel feedback information to the sending station after receiving the feedback request.

In one aspect, a wireless communication system is provided, including: a sending station and at least two receiving stations;

The sending site is the site provided in the above aspect;

Among the at least two receiving stations, all the receiving stations except the first receiving station are the stations provided in the above another aspect.

Embodiments of the present invention provide a method, device and system for channel detection. Since the sending stations send feedback requests to the receiving stations except the first one in sequence, and the receiving stations other than the first one do not have to keep Wait to receive the feedback request, but go to sleep until the scheduled sleep time is reached before waking up to receive the feedback request; in this way, the waiting time of the receiving site can be reduced as much as possible without affecting the reception of the feedback request. In order to achieve the purpose of saving electricity.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Figure 1 is a schematic diagram of the MU-MIMO scenario mechanism;

Fig. 2 is the frame format of IEEE802.11acNDPA broadcast packet;

FIG. 3 is a schematic diagram of a channel detection method provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of a channel detection method provided by another embodiment of the present invention;

FIG. 5 is a schematic diagram of a channel detection method provided by another embodiment of the present invention;

6 is a schematic flow chart of a method for calculating a predetermined sleep time;

7 is a schematic diagram of a method for calculating a predetermined sleep time;

FIG. 8 is a schematic diagram of a site structure provided by an embodiment of the present invention;

FIG. 9 is a schematic diagram of a site structure provided by another embodiment of the present invention;

Fig. 10 is a schematic diagram of a site structure provided by another embodiment of the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

An embodiment of the present invention provides a channel detection method, which can be used in the MU-MIMO scenario of a network composed of a basic service set (BSS) or an ad hoc network composed of a non-basic service set (BSS), the execution of each step of the method The subject may be a station. Specifically, in this embodiment, since the station serves as a beamforming initiator (beamformer) in the high-throughput detection mechanism, the station is called a sending station. Described method, as shown in Figure 3, comprises:

S101. The sending station sends an NDPA broadcast packet to notify the relevant receiving station to prepare for detection;

Usually, for a network composed of basic service sets, the physical device corresponding to Beamformer is an access point (AP, AccessPoint), and the physical device corresponding to Beamformee is a station (STA, Station); for non-basic service set ad hoc For the network, the physical device corresponding to Beamformer can be a certain STA, and the physical device corresponding to Beamformee can be other STAs.

S102. The sending station continues to send an empty NDP broadcast packet, so that after receiving the NDP broadcast packet, the relevant receiving station calculates the relevant channel feedback information;

S103. Receive the channel feedback information sent by the receiving station corresponding to the first station information carried in the NDPA broadcast packet;

From the frame format of the NDPA broadcast packet shown in Figure 2, it can be seen that the NDPA broadcast packet carries n (n≥2) station information (STAInformation, which can be abbreviated as STAInfo), which means that the sending station needs to receive n The channel feedback information of the receiving stations, and the n receiving stations are in one-to-one correspondence with the n STAInfo carried in the NDPA broadcast packet. In all embodiments of the present invention, the receiving site corresponding to the i (1≤i≤n) STAInfo (i.e. STAInfoi) carried in the NDPA broadcast packet is called the i receiving site; wherein, i is used as site information in NDPA The sequence number in the broadcast packet. Specifically, each receiving site has an association identity number (AssociationIdentity, hereinafter referred to as AID), and each STAInfo contains an AID; if the two AIDs are consistent, the two correspond.

In this step, the receiving site corresponding to the first site information carried in the NDPA broadcast packet can be called the first receiving site; specifically, the first receiving site refers to the AID of the receiving site and the received The receiving stations with the same AID in the first STAInfo (ie STAInfo1) field in the NDPA broadcast packet are consistent. After the first receiving station receives the NDP broadcast packet, it performs channel estimation based on the received NDP broadcast packet and calculates the channel feedback information from the channel estimation, and does not go to sleep until the channel feedback information is sent to the sending station, making this step The sending station first receives the channel feedback information of the first receiving station.

S104. Send feedback requests to other receiving stations sequentially from front to back according to the sequence of station information in the NDPA broadcast packet, so as to receive channel feedback information sent by other receiving stations.

The arrangement order of the station information in the NDPA broadcast packet is the order of the above n station information. The other stations refer to receiving stations other than the first receiving station, specifically the second to nth receiving stations.

This step is specifically that the sending station sequentially sends feedback requests to the second to nth receiving stations, so as to receive channel feedback information of these receiving stations. In practical applications, the sending station needs to obtain the channel feedback information of the receiving station. However, due to some abnormal conditions (such as incorrect parsing of NDPA frames, etc.), it is also possible that the sending station sent a feedback request, but the receiving station did not send The channel feeds back information to the sending site.

In the channel detection method provided by the embodiment of the present invention, the sending station receives an NDPA broadcast packet and an NDP broadcast packet in a MU-MIMO scenario of a network composed of a BSS or an ad hoc network composed of a non-basic service set BSS. The channel feedback information sent by the receiving station corresponding to the first station information carried in the broadcast packet; according to the arrangement order of the station information in the NDPA broadcast packet from front to back, send feedback requests to other receiving stations in order to receive the channels sent by other receiving stations Feedback. Compared with the sending station in the prior art that randomly sends feedback requests to other receiving stations except the first one, the receiving stations other than the first do not have to wait to receive the feedback request, but go to sleep until the scheduled time is reached. In this way, the waiting time of the receiving station can be reduced as much as possible without affecting the reception of feedback requests, thereby achieving the purpose of power saving.

The embodiment of the present invention provides another method for channel detection, which can be used in an MU-MIMO scenario of a network composed of a basic service set (BSS) or an ad hoc network composed of a non-basic service set (BSS), the steps of the method The executor may be a station. Specifically, in this embodiment, since the station serves as a beamformee in the high-throughput detection mechanism, the station is called a receiving station. And it should be noted that since the first receiving station does not go to sleep and immediately sends channel feedback information to the sending station, the whole process of channel detection is the same as the existing method for the first receiving station; Fig. The method shown in 4 is applicable to other receiving sites than the first receiving site. That is to say, the subject of execution of the method is any one of the second to nth receiving stations. Described method is as shown in Figure 4, comprises:

S201. Receive the NDPA broadcast packet sent by the sending site, and make detection preparations;

S202. Receive the NDP broadcast packet sent by the sending station, and calculate the channel feedback information related to itself;

According to the existing technology, this step can be as follows: receiving the NDP broadcast packet sent by the sending station, performing channel estimation according to the received NDP broadcast packet, and calculating the channel feedback information related to itself by the channel estimation.

S203. When going to sleep until the scheduled sleep time is reached, wake up yourself to receive the feedback request sent by the sending site;

Wherein, the predetermined sleep time may be obtained based on experience and pre-stored in the receiving station in advance, of course, it may also be stored in the database of other devices, after the receiving station and the sending station have just established a connection, and Before performing S201, each receiving station reads the predetermined sleep time from the database. However, in the embodiment of the present invention, as for how to obtain the predetermined sleep time, reference may be made to the following specific method, which is performed only after the NDPA broadcast packet is received in S201.

In this way, the receiving stations other than the first can wake themselves up according to the preset sleep time, so that other receiving stations do not have to wait to receive the feedback request, but go to sleep until the predetermined sleep time is reached before waking themselves up to receive the feedback request. Feedback request, thus, the waiting time of the receiving station can be reduced as much as possible without affecting the reception of the feedback request, so as to achieve the purpose of power saving.

S204. After receiving the feedback request, send channel feedback information to the sending station.

It should be noted that, the feedback request described in all embodiments of the present invention is a beamforming report query (BeamformingRepotPoll).

The specific method for how to get the scheduled sleep time will be elaborated below:

If the execution subject of the method shown in Figure 4 is the corresponding receiving site (i.e. the second receiving site) of the second site information recorded in the NDPA broadcast packet, then when step S203 is performed, the scheduled sleep time is a short frame Interval (ShortInter-FrameSpace, can be abbreviated as SIFS) duration. The predetermined sleeping time may be pre-stored in the second receiving station, and of course, may also be calculated by a formula.

If the subject of execution of the method shown in Figure 4 is the receiving site corresponding to the third or subsequent site information recorded in the NDPA broadcast packet, as shown in Figure 5, before going to sleep, S205, according to the beam The length of the shaping report query, the modulation and coding scheme (Modulation and Coding Scheme, which can be abbreviated as MCS) for encoding and modulating the beamforming report query, and the sequence number of the station information corresponding to the receiving station in the NDPA broadcast packet, calculate the scheduled sleep time time. It should be noted that the sequence of executing step S205 does not necessarily follow the sequence shown in FIG. 5 . In this embodiment of the present invention, it is only emphasized that step S205 is performed before step S203. For example, the receiving site can execute S205 in the SIFS between step S201 and step S202; it can also execute S205 in the SIFS between step S202 and step S203; of course, in the embodiment of the present invention, it does not exclude the situation that S202 and S205 are performed simultaneously .

Wherein, according to the prior art, the frame structure of the beamforming report query is known, so its length is also known. In addition, the modulation and coding scheme may be obtained by the execution subject of the method shown in FIG. 5 (the receiving station corresponding to the information of the third or any subsequent station) according to channel conditions, and the modulation and coding scheme includes: coding rate and modulation rate.

Wherein, as shown in FIG. 6, step S205 may include:

S2051. Determine the length of the encoded beamforming report query according to the length of the beamforming report query and the coding mode in the modulation and coding scheme;

Exemplarily, the length L_codeData of the encoded beamforming report query is determined according to the length L_data of the beamforming report query and the coding rate Cr (the highest order MCS coding rate) in the modulation and coding scheme:

L_codeData=L_data/Cr+tailbit

Wherein, the encoding rate Cr may be an actually estimated value, or a slightly larger value than the actual estimated value; tailbit is a tail bit for BCC encoding to reset the delay register to zero.

S2052. Determine the length of the modulated beamforming report query according to the length of the coded beamforming report query and the modulation mode in the modulation and coding scheme;

The modulation methods generally include: Binary phase shift keying (Binary phase shift keying, can be abbreviated as BPSK), quadrature phase shift keying (Quadrature phase shift keying, can be abbreviated as QPSK), quadrature amplitude modulation (Quadrature Amplitude Modulation, can be abbreviated as QAM, QAM is divided into 64QAM, 256QAM) and the modulation rates corresponding to various modulation methods are: BPSK is 1bit/symbol; QPSK is 2bit/symbol; 16QAM is 4bit/symbol; 64QAM is 6bit/symbol; 256QAM is 8bit/symbol)

Exemplarily, this step may be calculating the modulated data length L_modulatedData=L_codeData/M according to the length L_codeData and the modulation rate M of the above coded beamforming report query.

S2053. Determine the number of OFDM symbols for the modulated beamforming report query according to the length of the modulated beamforming report query and the number of data subcarriers of the Orthogonal frequency division multiplexing (OFDM) symbols;

Exemplarily, the symbol number N_sym=L_modulatedData/N_data is calculated according to the modulated data length L_modulatedData and the OFDM symbol data subcarrier number N_data.

S2054. Calculate the minimum time required for sending the modulated beamforming report query from the number of OFDM symbols of the modulated beamforming report query and the frame structure of the physical layer header;

Specifically, as shown in FIG. 7 , calculate the minimum time minT _brp =8+8+4+8+4+4+4+4+4×N_sym=44+4×N_sym required for sending the modulated beamforming report query (us), where the time required to send one OFDM symbol is 4us, and the modulation rate is the highest-order MCS.

S2055. According to the formula ST _i =T _SIFS +(i-2)*(2*T _SIFS +minT _brp ), obtain a predetermined sleep time.

It should be noted that the formula ST _i =T _SIFS +(i-2)*(2*T _SIFS +minT _brp ) can be obtained as shown in Figure 1; where, ST _i represents the i-th recorded in the NDPA broadcast packet The predetermined sleep time of the receiving station corresponding to the station information, where i≥3; T _SIFS represents the duration of one SIFS; minT _brp represents the minimum time required for sending the modulated beamforming report query.

The channel detection method provided by the embodiment of the present invention makes the receiving stations except the first one not have to wait to receive the feedback request all the time, but go to sleep until the predetermined sleep time is reached before waking up to receive the feedback request; in this way , the waiting time of the receiving station can be reduced as much as possible without affecting the reception of the feedback request, thereby achieving the purpose of power saving.

To sum up, the present invention is a channel detection completed on the basis of FIG. 1. The embodiment of the present invention specifically includes: in the MU-MIMO scenario of a network composed of a BSS or an ad hoc network composed of a non-Basic Service Set BSS, The sending station (beamformer) first sends an NDPA broadcast packet to all relevant receiving stations (beamformee); the receiving station is ready to detect after receiving the NDPA broadcast packet; the sending station continues to send the NDP broadcast packet; the receiving station receives the NDP broadcast After completing the calculation of the relevant channel feedback information; then the first receiving station (beamformee1, which corresponds to the first STAInfo field of NDPA) immediately sends its own channel feedback information to the sending station, except for the first receiving station Other receiving stations outside the station all go to sleep, and of course, other receiving stations at this time have obtained their own scheduled sleep time; after that, the sending station sends information to the other receiving stations according to the arrangement order of the station information in the NDPA broadcast packet from front to back. Send a feedback request, correspondingly, each of the other receiving stations wakes up when its own scheduled sleep time arrives, to receive the feedback request, and sends its own related information to the sending station after receiving the feedback request Channel feedback information.

Compared with the prior art, in the method in the embodiment of the present invention, the sequential sending of feedback requests by the sending station provides conditions for the receiving station to have a predetermined sleep time; the receiving station can be in sleep during the predetermined sleep time state, wake up when the scheduled sleep time arrives, which will not affect the normal operation of the system, but also make the receiving station reduce the waiting time as much as possible, so as to achieve the purpose of power saving.

An embodiment of the present invention provides a station 40. Specifically, in this embodiment, since the station is used as a beamformer (beamformer) in a high-throughput detection mechanism, the station is called a sending station. The station 40 is a sending station, which corresponds to the method shown in FIG. 4 above. As shown in Figure 8, the site 40 includes:

The NDPA broadcast packet sending unit 401 is used to send an NDPA broadcast packet to notify all relevant receiving stations to prepare for detection;

Usually, for a network composed of basic service sets, the physical device corresponding to Beamformer is an access point (AP, AccessPoint), and the physical device corresponding to Beamformee is a station (STA, Station); for non-basic service set ad hoc For the network, the physical device corresponding to Beamformer can be a certain STA, and the physical device corresponding to Beamformee can be other STAs.

The NDP broadcast packet sending unit 402 is used to continue to send an empty NDP broadcast packet, so that after the relevant receiving station receives the NDP broadcast packet, it calculates the respective relevant channel feedback information;

The first channel feedback information receiving unit 403 is configured to receive the channel feedback information sent by the receiving station corresponding to the first receiving station information carried in the NDPA broadcast packet;

From the frame format of the NDPA broadcast packet shown in Figure 2, it can be seen that the NDPA broadcast packet carries n (n≥2) station information (STAInformation, which can be abbreviated as STAInfo), which means that the sending station needs to receive n The channel feedback information of the receiving stations, and the n receiving stations are in one-to-one correspondence with the n STAInfo carried in the NDPA broadcast packet. In all embodiments of the present invention, the receiving site corresponding to the i (1≤i≤n) STAInfo (i.e. STAInfoi) carried in the NDPA broadcast packet is called the i receiving site; wherein, i is used as site information in NDPA The sequence number in the broadcast packet. Specifically, each receiving site has a connection identity number (AssociationID, hereinafter abbreviated as AID), and each STAInfo contains an AID; if the two AIDs are the same, the two correspond.

In this unit, the receiving site corresponding to the first site information carried in the NDPA broadcast packet can be called the first receiving site; specifically, the first receiving site refers to the AID of the receiving site and the received The receiving stations with the same AID in the first STAInfo (ie STAInfo1) field in the NDPA broadcast packet are consistent. After the first receiving station receives the NDP broadcast packet, it performs channel estimation according to the received NDP broadcast packet and calculates the channel feedback information based on the channel estimation, until the channel feedback information is sent to the sending station, so that the sending station first receives the first The channel feedback information of each receiving station.

The second channel feedback information receiving unit 404 is configured to sequentially send feedback requests to other receiving stations according to the sequence of station information in the NDPA broadcast packet, so as to receive channel feedback information sent by other receiving stations.

The arrangement order of the station information in the NDPA broadcast packet is the order of the above n station information. The other stations refer to receiving stations other than the first receiving station, specifically the second to nth receiving stations.

It should be noted that the sending station sequentially sends feedback requests to the second to nth receiving stations, so as to receive channel feedback information of these receiving stations. In practical applications, the sending station needs to obtain the channel feedback information of the receiving station. However, due to some abnormal conditions (such as incorrect parsing of NDPA frames, etc.), it is also possible that the sending station sent a feedback request, but the receiving station did not send The channel feeds back information to the sending site.

In the station provided by the embodiment of the present invention, the sending station receives the NDPA broadcast packet after sending an NDPA broadcast packet and an NDP broadcast packet in a MU-MIMO scenario of a network composed of a BSS or an ad hoc network composed of a non-basic service set BSS The channel feedback information sent by the receiving station corresponding to the first station information carried in the NDPA broadcast packet; according to the arrangement order of the station information in the NDPA broadcast packet, send feedback requests to other receiving stations in order to receive the channel feedback information sent by other receiving stations . Compared with the sending station in the prior art that randomly sends feedback requests to other receiving stations except the first one, the receiving stations other than the first do not have to wait to receive the feedback request, but go to sleep until the scheduled time is reached. In this way, the waiting time of the receiving station can be reduced as much as possible without affecting the reception of feedback requests, thereby achieving the purpose of power saving.

The embodiment of the present invention provides another station 50. Specifically, in this embodiment, since the station is used as a beamforming receiver (beamformee) in the high-throughput detection mechanism, the station is called a receiving station. And it should be noted that since the first receiving station does not go to sleep and immediately sends channel feedback information to the sending station, the whole process of channel detection is the same as the existing method for the first receiving station; Fig. The station 50 method shown in 9 is applicable to other receiving stations than the first receiving station. That is to say, the subject of execution of the method site 50 is any one of the second to nth receiving sites. Described method station 50 is shown in Figure 9, comprises:

The NDPA broadcast packet receiving unit 501 is used to receive the NDPA broadcast packet sent by the sending site for detection preparation;

The NDP broadcast packet receiving unit 502 is used to receive the NDP broadcast packet sent by the sending station, and calculate the channel feedback information related to itself;

The NDP broadcast packet receiving unit 502 is specifically configured to receive the NDP broadcast packet sent by the sending site, perform channel estimation according to the received NDP broadcast packet, and calculate channel feedback information related to itself by the channel estimation.

The wake-up unit 503 is configured to wake up itself when going to sleep until a predetermined sleep time is reached, so as to wait for receiving the feedback request sent by the sending site;

In this way, the receiving stations other than the first can wake themselves up according to the preset sleep time, so that other receiving stations do not have to wait to receive the feedback request, but go to sleep until the predetermined sleep time is reached before waking themselves up to receive the feedback request. Feedback request, thus, the waiting time of the receiving station can be reduced as much as possible without affecting the reception of the feedback request, so as to achieve the purpose of power saving.

The feedback information sending unit 504 is configured to send channel feedback information to the sending site after receiving the feedback request.

It should be noted that the feedback request described in all embodiments of the present invention is a beamforming report query (BeamformingRepotPoll)

Further, if the station shown in Figure 9 is the receiving station corresponding to the second station information recorded in the NDPA broadcast packet (i.e. the second receiving station), then the scheduled sleep time in the wake-up unit 503 is a short frame interval Duration of SIFS.

If the station shown in Figure 9 is the receiving station corresponding to the third or subsequent station information recorded in the NDPA broadcast packet, then as shown in Figure 10, the station 50 also includes a sleep time calculation unit 505 for The length of the shaping report query, the modulation and coding scheme for encoding and modulating the beamforming report query, and the sequence number of the station information corresponding to the receiving station in the NDPA broadcast packet are used to calculate the predetermined sleep time.

Wherein, according to the prior art, the frame structure of the beamforming report query is known, so its length is also known. In addition, the modulation and coding scheme may be estimated and obtained by the station in FIG. 10 (the receiving station corresponding to the information of the third or any subsequent station) according to channel conditions, and the modulation and coding scheme includes: a coding rate and a modulation rate.

Wherein, the sleep time calculation unit 505 may include:

The coded length calculation module 5051 is used to determine the length of the coded beamforming report query according to the length of the beamforming report query and the coding mode in the modulation and coding scheme;

Modulated length calculation module 5052, configured to determine the length of the modulated beamforming report query according to the length of the coded beamforming report query and the modulation mode in the modulation and coding scheme;

The number of OFDM symbols calculation module 5053 is used to determine the number of OFDM symbols of the modulated beamforming report query according to the length of the modulated beamforming report query and the number of data subcarriers of the OFDM symbol;

The shortest time calculation module 5054 is used to calculate the minimum time required to send the modulated beamforming report query from the number of OFDM symbols of the modulated beamforming report query and the frame structure of the physical layer header part;

The sleep time calculation module 5055 is used to obtain the predetermined sleep time according to the formula ST _i =T _SIFS +(i-2)*(2*T _SIFS +minT _brp ); wherein, ST _i represents the first time recorded by the NDPA broadcast packet. The predetermined sleep time of the receiving station corresponding to the i station information, where i≥3; T _SIFS represents the duration of one SIFS; minT _brp represents the minimum time required for sending the modulated beamforming report query.

The receiving station provided by the embodiment of the present invention makes the receiving station except the first one needn't wait to receive the feedback request all the time, but goes to sleep until the predetermined sleep time is reached before waking up to receive the feedback request; in this way, it can Without affecting the reception of feedback requests, the waiting time of the receiving station is reduced as much as possible, thereby achieving the purpose of power saving.

The wireless communication system provided by the embodiment of the present invention includes: a sending station and at least two receiving stations: the sending station is the above-mentioned station 40; the receiving stations except the first receiving station in the at least two receiving stations are all the above-mentioned stations 50 .

In the wireless communication system provided by the embodiment of the present invention, the sending station sends NDPA broadcast packets and NDP broadcast packets to the receiving station, and the sending station sends messages to other stations except the first station from front to back according to the sequence of station information in the NDPA broadcast packet Send a feedback request; when the receiving station receives the NDP broadcast packet, it calculates the channel feedback information according to the information recorded in the NDP broadcast packet. The NDPA broadcast packet calculates its own sleep time, so as to enter the sleep state, and does not wake itself until the predetermined sleep time is reached. In this way, the waiting time of the receiving station can be reduced as much as possible, so as to achieve the purpose of saving power.

Those of ordinary skill in the art can understand that all or part of the steps for realizing the above-mentioned method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the It includes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other various media that can store program codes.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (13)

1. A method for channel detection, characterized in that, comprising: Send an empty packet to notify the NDPA broadcast packet to notify the relevant receiving stations to prepare for detection; wherein, the NDPA broadcast packet carries the station information of at least two receiving stations, and the station information includes the sequence numbers of the receiving stations; Continue to send an empty packet NDP broadcast packet, so that after the relevant receiving station receives the NDP broadcast packet, calculate the respective relevant channel feedback information; Receive the channel feedback information sent by the receiving station corresponding to the first station information carried in the NDPA broadcast packet; wherein, other receiving stations except the receiving station corresponding to the first station information are in sleep state until reaching Wake up at the scheduled sleep time to receive the feedback request sent by the sending site; Sending feedback requests to other receiving stations sequentially from front to back according to the station information arrangement sequence in the NDPA broadcast packet, so as to receive channel feedback information sent by the other receiving stations. 2. A method for channel detection, characterized in that, comprising: Receiving the empty packet sent by the sending site to notify the NDPA broadcast packet to prepare for detection; wherein, the NDPA broadcast packet carries site information of at least two receiving sites, and the site information includes the sequence number of the receiving site; Receive the empty packet NDP broadcast packet sent by the sending station, and calculate the channel feedback information related to itself; When going to sleep until the scheduled sleep time is reached, wake up yourself to receive the feedback request sent by the sending site; After receiving the feedback request, send the channel feedback information to the sending station. 3. The method according to claim 2, wherein the feedback request is a beamforming report query. 4. The method according to claim 3, wherein if the receiving station is the corresponding receiving station of the second station information recorded in the NDPA broadcast packet, then the predetermined sleep time is the duration of a short frame spacing SIFS . 5. The method according to claim 3, wherein if the receiving site is the third one recorded by the NDPA broadcast packet or the receiving site corresponding to any site information thereafter, before entering sleep, it also includes: The predetermined sleep time is calculated according to the length of the beamforming report query, the modulation and coding scheme for encoding and modulating the beamforming report query, and the sequence number of the station information corresponding to the receiving station in the NDPA broadcast packet. 6. The method according to claim 5, wherein, according to the length of the beamforming report query and the modulation and coding scheme for encoding and modulating the beamforming report query, calculating the predetermined sleep time includes: determining the length of the coded beamforming report query according to the length of the beamforming report query and the coding mode in the modulation and coding scheme; determining the length of the modulated beamforming report query according to the length of the coded beamforming report query and the modulation mode in the modulation and coding scheme; Determine the number of OFDM symbols for the modulated beamforming report query according to the length of the modulated beamforming report query and the number of data subcarriers of the OFDM symbol; Calculate the minimum time required to send the modulated beamforming report query by the number of OFDM symbols of the modulated beamforming report query and the frame structure of the physical layer header; According to the formula ST _i =T _SIFS +(i-2)*(2*T _SIFS +minT _brp ), the scheduled sleep time is obtained; wherein, ST _i represents the receiving site corresponding to the i-th site information recorded in the NDPA broadcast packet The predetermined sleep time, where i≥3; T _SIFS represents the duration of one SIFS; minT _brp represents the minimum time required for sending the modulated beamforming report query. 7. A site, characterized in that it comprises: The NDPA broadcast packet sending unit is used to send an empty packet to notify the NDPA broadcast packet to notify the relevant receiving sites to prepare for detection; wherein, the NDPA broadcast packet carries site information of at least two receiving sites, and the site information includes receiving the sequential number of the station; The NDP broadcast packet sending unit is used to continue to send an empty NDP broadcast packet, so that after the relevant receiving station receives the NDP broadcast packet, it calculates the respective relevant channel feedback information; The first channel feedback information receiving unit is configured to receive the channel feedback information sent by the receiving station corresponding to the first station information carried in the NDPA broadcast packet; wherein, except for the receiving station corresponding to the first station information The other receiving stations are in a sleep state until the scheduled sleep time is reached to wake themselves up to receive the feedback request sent by the sending station; The second channel feedback information receiving unit is configured to send feedback requests to other receiving stations sequentially from front to back according to the station information arrangement sequence in the NDPA broadcast packet, so as to receive the channel feedback information sent by the other receiving stations. 8. A site, characterized in that it comprises: The empty packet informs the NDPA broadcast packet receiving unit, which is used to receive the NDPA broadcast packet sent by the sending site, and prepare for detection; wherein, the NDPA broadcast packet carries site information of at least two receiving sites, and the site information includes the receiving site sequence number; The empty packet NDP broadcast packet receiving unit is used to receive the NDP broadcast packet sent by the sending station, and calculate the channel feedback information related to itself; The wake-up unit is used to wake up itself when going to sleep until the scheduled sleep time is reached, so as to receive the feedback request sent by the sending site; A feedback information sending unit, configured to send the channel feedback information to the sending station after receiving the feedback request. 9. The station according to claim 8, wherein the feedback request is a beamforming report query. 10. The station according to claim 9, wherein if the station corresponds to the second station information recorded in the NDPA broadcast packet, the predetermined sleep time is a duration of a short frame interval (SIFS). 11. The station according to claim 9, wherein if the station corresponds to the third or any subsequent station information recorded in the NDPA broadcast packet, the station also includes: A sleep time calculation unit, configured to calculate according to the length of the beamforming report query, the modulation and coding scheme for encoding and modulating the beamforming report query, and the sequence number of the station information corresponding to the receiving station in the NDPA broadcast packet. The predetermined sleep time. 12. The station according to claim 11, wherein the sleep time calculation unit comprises: A coded length calculation module, configured to determine the length of the coded beamforming report query according to the length of the beamforming report query and the coding mode in the modulation and coding scheme; A modulated length calculation module, configured to determine the length of the modulated beamforming report query according to the length of the coded beamforming report query and the modulation mode in the modulation and coding scheme; The OFDM symbol number calculation module is used to determine the number of OFDM symbols of the modulated beamforming report query according to the length of the modulated beamforming report query and the number of data subcarriers of the OFDM symbol; The shortest time calculation module is used to calculate the minimum time required to send the modulated beamforming report query from the number of OFDM symbols of the modulated beamforming report query and the frame structure of the physical layer header; The sleep time calculation module is used to obtain the predetermined sleep time according to the formula ST _i =T _SIFS +(i-2)*(2*T _SIFS +minT _brp ); wherein, ST _i represents the i-th recorded by the NDPA broadcast packet The scheduled sleep time of the receiving station corresponding to the station information, where i≥3; T _SIFS represents the duration of one SIFS; minT _brp represents the minimum time required to send the modulated beamforming report query. 13. A wireless communication system, comprising: a sending station and at least two receiving stations; The sending site is the site described in claim 7; Among the at least two receiving stations, all receiving stations except the first receiving station are the stations described in any one of claims 8-12.