WO2016138659A1

WO2016138659A1 - Phase deviation calculation method, access point and station

Info

Publication number: WO2016138659A1
Application number: PCT/CN2015/073684
Authority: WO
Inventors: 吴涛
Original assignee: 华为技术有限公司
Priority date: 2015-03-05
Filing date: 2015-03-05
Publication date: 2016-09-09

Abstract

Provided in embodiments of the present invention are a phase deviation calculation method, access point and station. The phase deviation calculation method of the present invention comprises: determining a frequency domain sequence of a hybrid pilot sequence, the hybrid pilot sequence comprising pilot sequences of multiple stations; extracting, according to a pilot model of the station, a sub-sequence of the stations, and determining, according to the pilot sequence of the stations generated by the sub-sequence of the station, phase deviations of the stations. The embodiment of the present invention reduces a bit error rate on receiving a signal resulting from residual deviation.

Description

Phase deviation calculation method, access point and site

Technical field

Embodiments of the present invention relate to communication technologies, and in particular, to a phase deviation calculation method, an access point, and a station.

Background technique

Wireless-Fidelity (WiFi) technology is the main technical standard of the Wireless Local Area Networks (WLAN) system, and the technical standards established by the Institute of Electrical and Electronics Engineers (IEEE). 802.11, in various versions such as 802.11a, 802.11b, 802.11d, 802.11n and 802.11ac, the technology development has become more and more mature, and the transmission speed is also getting higher and higher. On the other hand, due to the unique flexibility of WiFi technology, it has become more and more used in home and business environments. In the WiFi-based WLAN network, the receiver performs a baseband processing procedure on the received signal, which mainly includes: symbol synchronization, channel estimation, and data preprocessing. The symbol synchronization refers to performing symbol synchronization according to the received Short Training Field (STF) and the received signal, and implementing frequency synchronization and time synchronization between the transmitter and the receiver. The channel estimation is actually using the received Long Training Field (LTF) for channel estimation to obtain channel information. The data pre-processing actually refers to channel equalization of the signal according to the channel information obtained by the channel estimation to eliminate the influence of the channel.

Although the receiver can implement frequency synchronization between the transmitter and the receiver according to the STF, it is impossible to achieve complete frequency synchronization, and thus there is a certain residual frequency offset.

However, the presence of this residual frequency offset can result in a phase offset in the signal received by the receiver. The phase deviation caused by the residual frequency offset makes the received signal have a high bit error rate and cannot even be demodulated.

Summary of the invention

Embodiments of the present invention provide a phase deviation calculation method, an access point, and a station to solve the problem of a high bit error rate of a received signal caused by a phase deviation caused by a residual frequency offset.

In a first aspect, an embodiment of the present invention provides a phase deviation calculation method, including:

An access point determines a frequency domain sequence of the hybrid pilot sequence, wherein the hybrid pilot sequence includes pilot sequences of a plurality of stations;

And the access point extracts, according to a pilot model of each of the multiple sites, a subsequence corresponding to each of the sites from the frequency domain sequence; wherein, a frequency of a pilot model of each of the sites The offset generated by the phase deviation of each of the stations is different from the offset of the frequency of the pilot models of other stations to the phase deviation of the other stations; the other stations are the plurality of wireless local area networks Sites outside each site described in the site;

Generating, by the access point, a pilot sequence of each site according to a subsequence corresponding to each site;

The access point determines a phase offset of each of the stations based on a pilot sequence of each of the stations.

According to a first aspect, in a first possible implementation manner of the first aspect, the pilot model of each of the stations is

l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant, Δ is the frequency of the pilot model of each station, and L is the time domain sampling length.

According to the first aspect or the first possible implementation manner of the first aspect, in a second possible implementation manner, before the determining, by the access point, the frequency domain sequence of the mixed pilot sequence, the method further includes:

The access point allocates a pilot model to each of the multiple sites;

The access point transmits a pilot model assigned to the plurality of sites to the plurality of sites, respectively.

In a second aspect, an embodiment of the present invention provides a phase deviation calculation method, including:

Generating, by the station, a pilot signal according to a pilot model of the station, wherein a frequency of a pilot model of the station produces an offset from a phase deviation of the station, different from a frequency of a pilot model of another station Offset due to phase deviation of other stations; the other stations are sites outside the site in the WLAN;

The station transmits the generated pilot signal.

According to a second aspect, in a first possible implementation manner of the second aspect, the pilot model of the station is

l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant; Δ is the frequency of the pilot model of the station, and L is the time domain sampling length.

According to the second aspect or the first possible implementation manner of the second aspect, in a second possible implementation manner, before the station generates a pilot signal according to the pilot model of the station, the method Also includes:

The station receives a pilot model of the station assigned by an access point.

In a third aspect, an embodiment of the present invention provides an access point, including:

a determining module, configured to determine a frequency domain sequence of the mixed pilot sequence, wherein the mixed pilot sequence includes a pilot sequence of a plurality of stations;

And an extracting module, configured to extract a subsequence corresponding to each of the sites from the frequency domain sequence according to a pilot model of each of the multiple sites; wherein, a frequency of a pilot model of each site The offset generated by the phase deviation of each of the stations is different from the offset of the frequency of the pilot models of other stations to the phase deviation of the other stations; the other stations are the plurality of wireless local area networks Sites outside each site described in the site;

a generating module, configured to generate, according to the sub-sequence corresponding to each station, a pilot sequence of each station;

The determining module is further configured to determine a phase deviation of each of the stations according to a pilot sequence of each of the stations.

According to a third aspect, in a first possible implementation manner of the third aspect, the pilot model of each of the stations is

According to the third aspect or the first possible implementation manner of the third aspect, in a second possible implementation manner, the access point further includes:

An allocating module, configured to allocate a pilot model to each of the plurality of stations before the determining module determines the frequency domain sequence of the mixed pilot sequence;

And a sending module, configured to separately send a pilot model allocated to the multiple sites to the multiple sites.

In a fourth aspect, an embodiment of the present invention provides a site, including:

Generating a module, configured to generate a pilot signal according to a pilot model of the station, where a frequency of a pilot model of the station generates an offset from a phase deviation of the station, different from a pilot model of another station An offset of the frequency deviation from the phase deviation of the other stations; the other site is a site outside the site in the wireless local area network;

A sending module, configured to send the generated pilot signal.

According to a fourth aspect, in a first possible implementation of the fourth aspect, the pilot model of the station is

According to the fourth aspect or the first possible implementation manner of the fourth aspect, in a second possible implementation manner, the site further includes:

And a receiving module, configured to receive, before the generating module generates a pilot signal according to the pilot model of the station, a pilot model of the station allocated by the access point.

In a fifth aspect, an embodiment of the present invention provides an access point, including: a receiver, a processor, and a transmitter;

The processor is configured to determine a frequency domain sequence of the mixed pilot sequence, and extract a subsequence corresponding to each site from the frequency domain sequence according to a pilot model of each of the multiple sites. Generating, according to the sub-sequence corresponding to each station, a pilot sequence of each station, and determining a phase deviation of each station according to a pilot sequence of each station;

The hybrid pilot sequence includes a pilot sequence of a plurality of stations; a frequency of a pilot model of each of the stations produces an offset from a phase offset of each of the stations, different from pilots of other stations. The frequency of the model is offset from the phase deviation of the other stations; the other stations are stations outside each of the plurality of stations in the wireless local area network.

According to a fifth aspect, in a first possible implementation manner of the fifth aspect, the pilot model of each of the stations is

According to the fifth aspect or the first possible implementation manner of the fifth aspect, in a second possible implementation manner, the processor is further configured to determine, at the processor, the frequency of the mixed pilot sequence Prior to the domain sequence, a pilot model is assigned to each of the plurality of sites;

The transmitter is configured to separately send pilot models of the multiple sites to the multiple sites.

In a sixth aspect, an embodiment of the present invention provides a station, including: a receiver, a processor, and a transmitter;

The processor is configured to generate a pilot signal according to a pilot model of the station, where a frequency of a pilot model of the station is offset from a phase deviation of the station, different from that of other stations. The frequency of the pilot model is offset from the phase deviation of the other stations; the other stations are stations outside the station in the wireless local area network;

The transmitter is configured to send the generated pilot signal.

According to a sixth aspect, in a first possible implementation manner of the sixth aspect, the pilot model of the station is

According to the sixth aspect or the first possible implementation manner of the sixth aspect, in a second possible implementation manner, the receiver is configured to generate, at the processor, a pilot signal according to a pilot model of the station Previously, the pilot model of the site assigned by the access point was received.

Embodiments of the present invention provide a phase offset calculation method, an access point, and a station, where a frequency domain sequence of a mixed pilot sequence is determined by an access point, where the mixed pilot sequence includes pilot sequences of multiple sites, since each The frequency of the pilot model of the station is offset from the phase deviation of each station, and the frequency of the pilot model of other stations is offset from the phase deviation of the other stations, so the access station can be based on a pilot model of each of the plurality of sites extracts a subsequence corresponding to each site from the sequence of the frequency domain, and then generates a pilot sequence of each site according to the subsequence corresponding to each site, and according to The pilot sequence of each station determines the phase deviation of each station, so that phase compensation can be performed according to the phase deviation of the transmitting antennas of each station, and the error rate of the received signal caused by the residual deviation is reduced.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief description of the drawings used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor.

1 is a schematic diagram of a applicable scenario of a phase deviation calculation method according to various embodiments of the present invention;

2 is a flowchart of a phase deviation calculation method according to Embodiment 1 of the present invention;

3 is a flowchart of a phase deviation calculation method according to Embodiment 2 of the present invention;

4 is a flowchart of a phase deviation calculation method according to Embodiment 3 of the present invention;

5 is a flowchart of a phase deviation calculation method according to Embodiment 4 of the present invention;

6 is a flowchart of a phase deviation calculation method according to Embodiment 5 of the present invention;

7 is a flowchart of a phase deviation calculation method according to Embodiment 5 of the present invention;

8 is a flowchart of a phase deviation calculation method according to Embodiment 6 of the present invention;

9 is a schematic structural diagram of an access point according to Embodiment 7 of the present invention;

10 is a schematic structural diagram of a station according to Embodiment 8 of the present invention;

11 is a schematic structural diagram of an access point according to Embodiment 9 of the present invention;

FIG. 12 is a schematic structural diagram of a station according to Embodiment 10 of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The solution of this embodiment can be applied to the WiFi technology of the 802.11 version and above and the WLAN network system of the MIMO technology. FIG. 1 is a schematic diagram of an applicable scenario of a phase deviation calculation method according to various embodiments of the present invention. As shown in FIG. 1, the WLAN network system may include one access point 101 and at least two sites 102. The access point 101 includes at least two receive antennas, each of which may include at least one transmit antenna. The solution of this embodiment is applicable to the scenario that the access point receives the spatial stream of the at least two stations transmitting the spatial stream through the respective antennas through the at least two receiving antennas. Wherein each transmitting antenna can transmit a spatial stream.

A station (Station, also referred to as STA), which may also be called a user equipment, may be a wireless sensor, a wireless communication terminal or a mobile terminal, such as a mobile phone (or "cellular" phone) that supports WiFi communication function and has wireless communication function. computer. For example, it may be a portable, pocket-sized, handheld, computer-built, wearable, or in-vehicle wireless communication device that supports WiFi communication functions, and exchanges communication data such as voice and data with the wireless access network. An access point (AP), also referred to as a wireless access point or bridge or hotspot, can access a server or a communication network. Those skilled in the art are aware that some communication devices may have the functions of the above-mentioned access points or sites, and are not limited herein.

Embodiment 1 of the present invention provides a phase deviation calculation method. FIG. 2 is a flowchart of a phase deviation calculation method according to Embodiment 1 of the present invention. This method is performed by the access point. As shown in FIG. 2, the method provided in Embodiment 1 of the present invention may include:

S201. The access point determines a frequency domain sequence of the mixed pilot sequence, where the mixed pilot sequence includes a pilot sequence of multiple sites.

The hybrid pilot sequence may be a time domain sample sequence of a time domain mixed signal of a pilot sequence transmitted by the plurality of stations in the wireless local area network received by the access point. The access point determines a frequency domain sequence of the mixed pilot sequence, and may be a frequency domain sequence corresponding to a time domain sampling point obtained by performing a Discrete Fourier Transform (DFT) on the mixed pilot sequence.

For example, if the number of stations in the WLAN is n, n is an integer greater than or equal to 2. The mixed pilot sequence may be a mixed sequence of pilot sequences of the n stations in the time domain. The noise is ignored, the l th time-domain samples mixed conductor carrier access point on the sub-side m-th pilot pilot sequence may be r _m (l). The r _m (l) can be expressed by the following formula (1).

……Formula 1)

Where r _mn (l) is the time domain sampling point corresponding to the nth station in the first time domain sampling point. h _mn is the channel information of the transmitting antenna of the nth station in the WLAN on the pilot subcarrier m to the receiving antenna of the access point. p _n (l) is the lth time domain sampling point of the pilot model of the nth station. θ _n can be the phase deviation of the nth site. The phase deviation of the nth station is a phase deviation of a transmit antenna of the nth station to a receive antenna of the access point.

If the time domain sampling length of the mixed pilot sequence is L, that is, L time domain sampling points, then l=0, 1, ..., L-1. For example, L is an integer power of 2, and the L is greater than or equal to 4. Then the frequency domain sequence obtained by DFT transforming the mixed pilot sequence

It can be as shown in the following formula (2).

...formula (2)

among them,

The sub-site corresponding to the sub-sequence in the frequency domain sequence.

S202. The access point extracts a subsequence corresponding to each site from the frequency domain sequence according to a pilot model of each of the multiple sites; wherein, the frequency of the pilot model of each site is The offset generated by the phase deviation of the stations is different from the offset of the frequency of the pilot model of other stations to the phase deviation of the other stations; the other stations are outside the each of the multiple sites in the WLAN Other points.

Specifically, the offset of the frequency of the pilot model of each station to the phase deviation of each station may actually be the frequency of the pilot model of each station. Pilot model for this other site The offset of the frequency from the phase offset of the other station may be the frequency of the pilot model of the other station. Then, the frequency of the pilot model of each station is offset from the phase deviation of each station, and the frequency of the pilot model of other stations is offset from the phase deviation of the other stations. The frequency of the pilot model of each station is different from the frequency of the pilot model of the other station.

The frequencies of the pilot models of the plurality of stations constitute an equal sequence, for example, the frequency of the pilot model of the nth station is n Δ, where Δ is a preset offset value. Of course, the pilot sequences of the multiple stations may not constitute an equal sequence, and only the frequency of the pilot model of each station is required to be offset from the phase deviation of each station, unlike the pilots of other stations. The frequency of the model may be offset from the phase deviation of the other stations. In this case, when extracting a subsequence of each station, it is necessary to use at least some of the frequencies of the pilot models of the plurality of stations and a preset offset value.

Since the phase deviations of the different stations are different, and the frequency of the pilot model of the different stations is different from the phase deviation of the respective stations, the corresponding sub-sequences of the different stations in the frequency domain sequence are respectively different frequencies. A subsequence of points. Therefore, the access point extracts the sub-sequence corresponding to each station from the frequency domain sequence according to the pilot model of each of the multiple sites, which may be based on the frequency of the pilot model of each site, The frequency domain sequence is filtered to obtain a subsequence corresponding to each of the stations.

For example, if the frequency of the pilot model of the nth station in the WLAN is offset from the phase deviation of the nth station by Δ _n (ie, the frequency of the pilot model of the nth station is Δ _n ), The frequency of the pilot model of the n-1 station produces an offset of Δn _-1 for the phase deviation of the n-1th station (i.e., the frequency of the pilot model of the n-1th station is Δn _-1 ). Where Δ _n ≠ Δ _n-1 . If the Δ _n > Δ _n-1 , the sub-sequence corresponding to the nth site in the frequency domain sequence may be as shown in the formula (3).

...formula (3)

The access point extracts the subsequence corresponding to the nth station from the frequency domain sequence according to the pilot model of the nth station, and may be other frequencies in the frequency domain sequence according to the frequency of the pilot model of the nth station. The sequence of points is filtered to obtain a subsequence corresponding to the nth site. Specifically, it may be obtained by performing filtering according to the following formula (4).

...formula (4)

Among them, the

The subsequence corresponding to the nth station in the frequency domain sequence.

S203. The access point generates a pilot sequence of each site according to the subsequence corresponding to each site.

The access point may generate a pilot sequence of each station by performing an Inverse Discrete Fourier Transform (IDFT) on the sub-sequence corresponding to each station. The pilot sequence of each station may be a pilot sequence composed of discrete pilots in the time domain generated by the IDFT transform of each station.

The pilot sequence of the nth station can be respectively shown in the following formula (5).

...formula (5)

among them,

The pilot sequence for the nth site.

S204. The access point determines a phase offset of each station according to a pilot sequence of each station.

In order to eliminate the offset of the frequency of the pilot model of each station in the pilot sequence of each station for the phase deviation of each station, the access point also needs a pilot sequence for each station. The pilot model of each of the stations is conjugate multiplied, and then the phase deviation of each station is determined according to the pilot sequence of the each station after the conjugate multiplication. The access point determines a phase deviation of each station according to the pilot sequence of each of the sites after the conjugate multiplication, and may be adjacent to the pilot sequence of each station by multiplying the conjugate by the conjugate The pilot sequence of the time domain sampling point is conjugate multiplied and obtained by phase; the access point may also be determined by determining a plurality of adjacent time domain time domain sampling points among the plurality of time domain sampling points of each station. The pilot sequences are conjugate multiplied and the phase average of the phases is obtained. The access point conjugates the pilot sequence of each station with the pilot model of each station, which may be a conjugate of the pilot sequence of each station with the pilot model of each station. Make a difference.

The access point conjugate multiplies the pilot sequence of the nth station and the pilot model of the nth station, and may be a pilot sequence of the nth station and a pilot model of the nth station. The conjugate is phase-shifted to obtain a pilot sequence for the nth site that cancels the frequency effect of the pilot model. Specifically, it can be expressed by the following formula (6).

...Formula (6)

Where q _n (l) is the pilot sequence of the nth station that eliminates the influence of the frequency of the pilot model.

The access point determines the phase deviation of the nth station according to the pilot sequence of the nth station after the conjugate multiplication, that is, the pilot sequence of the nth station affected by the frequency of the pilot model, which may be determined according to Obtained as in the following formula (7).

...Formula (7)

If noise and interference are ignored, q _n (l+1)*conj(q _n (l)) in the above formula (7) can be expressed by the following formula (8).

...Formula (8)

The phase deviation calculation method provided by Embodiment 1 of the present invention may determine a frequency domain sequence of a mixed pilot sequence by using an access point, where the hybrid pilot sequence includes pilot sequences of multiple sites, because the pilot of each station The offset of the frequency of the model to the phase deviation of each of the stations is different from the offset of the frequency of the pilot model of the other stations to the phase deviation of the other stations, so the access station can a pilot model of each of the stations extracts a subsequence corresponding to each of the stations from the sequence of the frequency domain, and then generates a pilot sequence of each of the stations according to the subsequence corresponding to each of the stations, and according to each The pilot sequence of each station determines the phase deviation of each station, so that phase compensation can be performed according to the phase deviation of the transmitting antenna of each station, and the error rate of the received signal caused by the residual deviation is reduced.

It should be noted that, in the L time domain sampling points of the mixed pilot sequence, each time domain sampling point is taken from one symbol period, that is, the sampling interval is one symbol period, then the L time domain sampling points may be taken from Continuous L symbol periods. The consecutive L symbol periods may be time domain periods corresponding to L orthogonal frequency division multiplexing (OFDM) symbols in time domain. Those skilled in the art understand that the sampling interval can also be set according to specific needs.

Optionally, the pilot model of each site may be

l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant, and Δ is the frequency of the pilot model of each station, where L is the time domain sampling length.

Then, the pilot model of the nth station in the plurality of stations can be as shown in formula (9).

...formula (9)

The preset pilot p is a constant sequence, such that each item in the preset pilot sequence is an equal constant. The preset pilot can be a sequence of constants of 1, or other constants for each term. δ can be Preset constants, such as ±1. If the δ is 1, the phase of the pilot model of each station obtained by vector rotation of the frequency of the pilot model of each station may be a forward isometric sequence in turn. If the δ is -1, the phase of the pilot model of each station obtained by vector rotation of the frequency of the pilot model of each station may be a negative isometric sequence in sequence at the L time domain sampling points. .

FIG. 3 is a flowchart of a phase deviation calculation method according to Embodiment 2 of the present invention. As shown in FIG. 3, the method of the second embodiment, before the access point determines the frequency domain sequence of the mixed pilot sequence in the foregoing S201, further includes:

S301. The access point allocates a pilot model to each of the multiple sites.

S302. The access point sends the pilot models allocated to the multiple sites to the multiple sites.

The access station may be configured to allocate a pilot model for each of the multiple sites according to the pilot model of each of the sites, and the pilot models of different sites have different frequencies. The access station also transmits a pilot model assigned to the plurality of stations to the plurality of stations such that the plurality of stations can transmit pilot signals according to a pilot model set by the access station assignment.

According to the second embodiment of the present invention, on the basis of the foregoing Embodiment 1, the access station can be better ensured that the phase deviation of each station is more accurate, and the error rate of the received signal caused by the residual deviation is effectively reduced.

Embodiment 3 of the present invention further provides a phase deviation calculation method. The method of the third embodiment can be performed by any of the plurality of sites in the wireless local area network. 4 is a flowchart of a phase deviation calculation method according to Embodiment 3 of the present invention. As shown in FIG. 4, the method can include:

S401. A station generates a pilot signal according to a pilot model of the station, where a frequency of a pilot model of the station is offset from a phase deviation of the station, different from a frequency of a pilot model of another station to the other station. The offset caused by the phase deviation; the other site is the site outside the site in the WLAN.

The station generates a pilot signal according to the pilot model of the station, and may generate a pilot signal of the station at each time domain sampling point according to the pilot model of the station.

S402. The station sends the generated pilot signal.

Optionally, the pilot model of the site is

l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant; Δ is the frequency of the pilot model of the station; L is the time domain sampling length.

Optionally, before the method generates a pilot signal according to the pilot model of the site in S401, the method further includes:

The station receives the pilot model of the site assigned by the access point.

The method for calculating the phase deviation provided by the third embodiment of the present invention is a scheme executed by the site corresponding to the first embodiment or the second embodiment, and the beneficial effects thereof are similar to those of the foregoing embodiment, and details are not described herein again.

Embodiment 4 of the present invention further provides a phase deviation calculation method. The method of the fourth embodiment can be performed by any of the plurality of sites. FIG. 5 is a flowchart of a phase deviation calculation method according to Embodiment 4 of the present invention. As shown in FIG. 5, the method can include:

S501. The station determines, according to the pilot model of the station, a pilot signal of the station in consecutive L symbol periods; wherein, the frequency of the pilot model of the station is offset from the phase deviation of the station, different from The frequency of the pilot model of the other site is offset from the phase deviation of the other site; the other site is a site outside the each of the plurality of sites in the wireless local area network; L is an integer power of 2, and L Greater than or equal to 4.

In the fourth embodiment, the time domain sampling points may be consecutive L symbol periods.

S502. The station transmits a pilot signal of the station through a transmit antenna of the station in the consecutive L symbol periods.

A pilot signal of the station is transmitted through a transmit antenna of the station on each of the consecutive L symbol periods.

A phase deviation calculation method according to Embodiment 4 of the present invention, the station determines a pilot signal of the station in consecutive L symbol periods according to a pilot model of the station; wherein a frequency of a pilot model of the station is for the station The offset generated by the phase deviation is different from the offset of the frequency of the pilot model of the other station to the phase deviation of the other stations; the other station is a site outside the each of the plurality of stations in the wireless local area network; L is an integer power of 2, and L is greater than or equal to 4, so that the access point can determine the frequency domain sequence according to the mixed pilot sequence formed by the received pilot sequences sent by multiple stations, and determine the frequency domain sequence. The subsequence corresponding to each station generates a pilot sequence of each station according to the subsequence corresponding to each station, and then determines the phase deviation of each station according to the pilot sequence of each station, thereby reducing the received signal caused by residual deviation Bit error rate.

Optionally, in the method of Embodiment 4 of the present invention, the pilot model of the site is

l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant, and Δ is the frequency of the pilot model of the station.

Then, according to the nth station, the pilot sequence of the nth station in the 1st symbol period, that is, the 1st time domain sampling point, may be determined according to the pilot model of the nth station, such as

Where n = 1, ..., N; Δ _{n is} the frequency of the pilot model of the nth station. δ can be ±1.

The phase deviation calculation method provided in Embodiment 4 of the present invention can make the phase deviation of the transmitting antennas of each station determined by the access point more accurate, and the error rate of the received signal caused by the residual deviation is lower.

Embodiment 5 of the present invention also provides a phase deviation calculation method. The method of Embodiment 5 of the present invention can be performed by an access point. FIG. 6 is a flowchart of a phase deviation calculation method according to Embodiment 5 of the present invention. As shown in FIG. 6, the method can include:

S601. The access point receives pilot signals of each station sent by the multiple stations through respective transmit antennas in consecutive L symbol periods; wherein, the pilot signal of each station is for each of the stations according to the The pilot signal of each station determines the pilot signal of the each station in the consecutive L symbol periods; the frequency of the pilot model of each station produces an offset of the phase deviation of the station, different from other The frequency of the pilot model of the station is offset from the phase deviation of the other station; the other station is a station outside the each of the plurality of stations in the wireless local area network; L is an integer power of 2, and L is greater than Or equal to 4.

S602. The access point determines a mixed pilot sequence according to the pilot signals sent by the multiple stations received in the consecutive L symbol periods.

S603. The access point performs time-frequency domain transform on the mixed pilot sequence to determine a phase offset of each station.

The mixed pilot sequence is actually a time domain sequence of pilot sequences of the plurality of stations received during the consecutive L symbol periods. Performing a time-frequency domain transform on the mixed pilot sequence, the time domain sequence in the consecutive L symbol periods can be transformed into a frequency domain sequence. The time-frequency domain transform can be a Fourier transform, or any other transform that can convert a time domain sequence into a frequency domain sequence.

Optionally, the method of the fifth embodiment is based on the method of the foregoing fourth embodiment, where the pilot model of each station is

l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant, and Δ is the frequency of the pilot model for each station. δ can be ±1.

Then, the pilot sequence of the nth station in the lth symbol period, that is, the lth time domain sampling point is

Where n = 1, ..., N; Δ _{n is} the frequency of the pilot model of the nth station.

The time-frequency domain transform can be a DFT. The number L of symbol periods is an integer power of 2, and then the DFT may be a Fast Fourier Transform (FFT). Figure 7 is the basis A flowchart of a phase deviation calculation method of the fifth embodiment of the invention. As shown in FIG. 7, in the foregoing method, the method S603, the access point performs a time-frequency domain transformation on the mixed pilot sequence, and determines a phase deviation of the transmit antenna of each station, which may include:

S701. The access point performs DFT on the mixed pilot sequence to generate a frequency domain sequence of the mixed pilot sequence.

S702. The access point filters the frequency domain sequence according to the frequency of the pilot model of each site, and generates a subsequence corresponding to each site.

S703. The access point performs IDFT on the subsequence corresponding to each station, and determines a pilot sequence of each station.

S704. The access point determines a phase offset of each station according to a pilot sequence of each station.

Optionally, in S704, the access point determines the phase deviation of each site according to the pilot sequence of each site, which may include:

The access point determines the phase offset of each of the stations based on the phase of the pilot sequence for each of the consecutive L symbol periods.

Specifically, the access point may determine the phase deviation of each station according to the phase of the pilot sequence of each station in any one of the consecutive L symbol periods. The access point may also determine the phase offset of each of the stations based on a plurality of symbol periods, such as an average of the phases of the pilot sequences for each of the consecutive L symbol periods. Wherein, determining the phase deviation of each station according to the average value of the phases of the pilot sequences of each station in the consecutive L symbol periods, so that the phase deviation of each station is more accurate, and the residual deviation is caused by The received signal has a lower bit error rate.

The phase deviation calculation method of the fifth embodiment of the present invention can make the phase deviation of each station determined by the access point more accurate, and the error rate of the received signal caused by the residual deviation is lower.

Embodiment 6

Embodiment 6 of the present invention provides a phase deviation calculation method. The method of the sixth embodiment describes any one of the foregoing embodiments 1 to 5 by using a specific example in which the wireless local area network has two stations. FIG. 8 is a flowchart of a phase deviation calculation method according to Embodiment 6 of the present invention. As shown in FIG. 8, the method can include:

S801. The access point allocates a pilot model to each of the multiple sites.

The pilot model for each site can be

l=0,1,...,L-1, where p is a preset pilot, δ is ±1, Δ is the frequency of the pilot model of each station, where L is the time domain sampling length; The frequency of the pilot model of the stations is different from the frequency of the pilot models of the other stations.

S802. The access point sends the pilot model of each site to each of the sites.

S803. The each station generates a pilot sequence of each station in consecutive L symbol periods according to the pilot model of each station; L is an integer power of 2, and L is greater than or equal to 4.

For example, if the number of stations in the WLAN is 2, two stations in the WLAN, that is, the pilot sequence p ₁ of one subcarrier in each symbol period of the first station in the consecutive L symbol periods. The pilot sequence p ₂ of one subcarrier in each symbol period of the consecutive L symbol periods and the second station may be as shown in Table 1 below.

Table 1

S804. The each station transmits the pilot sequence of each station through the transmit antenna of each station in the consecutive L symbol periods.

The first station will transmit the pilot sequence p ₁ of the first station to the access point in the consecutive L symbol periods through the transmit antenna of the first station in the consecutive L symbol periods, and the second station will The pilot sequence p ₂ of the second station in the consecutive L symbol periods is transmitted to the access point through the transmit antenna of the second station during the consecutive L symbol periods.

S805. The access point determines, according to the pilot sequence of each station sent by the transmitting antenna corresponding to each station in the consecutive L symbol periods, a mixed pilot sequence including a pilot sequence of the multiple stations. .

S806. The access point performs DFT on the mixed pilot sequence to generate a frequency domain sequence.

The mixed pilot sequence received by the receiving antenna of the access point on the pilot subcarrier m in the first symbol period may be r _m (1). If noise is ignored, the r _m (l) can be expressed by the following formula (10).

...Formula (10)

Wherein, h _m1 is channel information of the receiving antenna of the transmitting antenna of the first station in the WLAN on the pilot subcarrier m to the receiving point of the access point. h _m2 is channel information of the transmitting antenna of the second station in the wireless local area network on the pilot subcarrier m to the receiving antenna of the access point. p ₁ (l) is the pilot model of the first station in the lth symbol period,

p ₂ (l) is the pilot model of the second station in the lth symbol period,

θ ₁ and θ ₂ may be phase deviations of the transmitting antennas of the first station and the second station to the receiving antennas of the access point, respectively.

The access point performs DFT on the mixed pilot sequence, and actually performs DFT on r _m1 (l) and r _m2 (l) therein.

The frequency domain sequence is

The

It can be as shown in the following formula (11).

...Formula (11)

among them,

with

The subsequence corresponding to the first station in the frequency domain sequence and the subsequence corresponding to the second station.

Therefore, in the frequency domain sequence, the subsequence corresponding to the first station, that is, the unit sequence signal width of the pilot sequence of the first station in the transform domain, that is, the frequency domain, is the guide of the first station. The frequency of the frequency model. Δ ₂ > Δ ₁ if the subsequence corresponding to the first station in the frequency domain sequence can be as shown in formula (12).

...formula (12)

The subsequence corresponding to the second station may be as shown in formula (13).

...Formula (13)

S807. The access point filters the frequency domain sequence according to the frequency of the pilot model of each site, and generates a subsequence corresponding to each site.

The access point may be the frequency domain sequence according to the frequency Δ ₂ of the pilot model of the second station.

Filtering to filter out

The subsequence corresponding to the second station obtains the subsequence corresponding to the first station, so that the subsequence corresponding to the first station is as shown in formula (14).

...Formula (14)

The

The subsequence corresponding to the first site.

The access point may be the frequency domain sequence according to the frequency Δ ₁ of the pilot model of the first station.

Filtering to filter out

The subsequence corresponding to the first station obtains a subsequence corresponding to the second station, and the subsequence corresponding to the second station may be as in formula (15).

...Formula (15)

The

The subsequence corresponding to the second site.

S808. The access point performs IDFT on the subsequence corresponding to each station, and generates a pilot sequence of each station, where the pilot sequence of each station includes a guide of each station in consecutive L symbol periods. Frequency sequence.

The access point may perform IDFT on the sub-sequence corresponding to the first station and the sub-sequence corresponding to the second station, and obtain the sub-sequence corresponding to the first station and the second station in the consecutive L symbol periods. Subsequence. The subsequence corresponding to the first station and the subsequence corresponding to the second station may be respectively shown in formula (16) and formula (17).

...Formula (16)

...Formula (17)

For the pilot sequence of the first site,

Is the pilot sequence for the second site.

S809. The access point determines a phase deviation of each station according to an average value of phases of the pilot sequences of each station in the consecutive L symbol periods.

The average of the phases of the pilot sequences of the first station in the consecutive L symbol periods can be as shown in equation (18).

...Formula (18)

Where conj(q ₁ (l)) is the conjugate of q ₁ (l), ∠{q ₁ (l+1)*conj(q ₁ (l))} is q ₁ (l+1)*conj( The phase of q ₁ (l)). Where q ₁ (l) can be as shown in formula (19).

...Formula (19)

If noise and interference are not considered, in equation (18), q ₁ (l+1)*conj(q ₁ (l)) can be as shown in equation (20).

...formula (20)

Correspondingly, the average value of the phases of the pilot sequences of the second station in the consecutive L symbol periods can be as shown in the formula (21).

...formula (21)

Where conj(q ₂ (l)) is the conjugate of q ₂ (l), ∠{q ₂ (l+1)*conj(q ₂ (l))} is q ₂ (l+1)*conj( The phase of q ₂ (l)). Where q ₂ (l) can be as shown in formula (22).

...Formula (22)

If noise and interference are not considered, q ₂ (l+1)*conj(q ₂ (l)) in the formula (21) can be expressed by the following formula (23).

...Formula (23)

The access point may be based on determining a phase deviation of the first station according to the formula (18), and determining a phase deviation of the second station according to the formula (23).

The method for calculating the phase deviation according to the sixth embodiment of the present invention is described by using the specific example to describe the method in any one of the foregoing Embodiments 1 to 5, and the beneficial effects are similar to those in the foregoing embodiment, and details are not described herein again.

Embodiment 7 of the present invention provides an access point. FIG. 9 is a schematic structural diagram of an access point according to Embodiment 7 of the present invention. The access point of the seventh embodiment can perform the phase deviation calculation method of any one of the first embodiment, the second embodiment or the fifth embodiment.

As shown in FIG. 9, the access point 900 can include a determining module 901, an extracting module 902, and a generating module 903.

The determining module 901 is configured to determine a frequency domain sequence of the mixed pilot sequence, where the mixed pilot sequence includes a pilot sequence of multiple sites.

The extracting module 902 is configured to extract, according to a pilot model of each of the multiple sites, the subsequence corresponding to each site from the frequency domain sequence; wherein, the frequency of the pilot model of each site is The offset generated by the phase deviation of the stations is different from the offset of the frequency of the pilot model of other stations to the phase deviation of the other stations; the other stations are outside the each of the multiple sites in the WLAN Site.

The generating module 903 is configured to generate a pilot sequence of each site according to the sub-sequence corresponding to each site.

The determining module 901 is further configured to determine a phase deviation of each station according to the pilot sequence of each station.

Optionally, the pilot model of each site is

Optionally, the access point 900 further includes:

And an allocating module, configured to allocate a pilot model to each of the plurality of stations before the determining module 901 determines the frequency domain sequence of the mixed pilot sequence.

And a sending module, configured to separately send a pilot model allocated for the multiple sites to the multiple sites.

The access point of the seventh embodiment of the present invention can perform the phase deviation calculation method of any one of the foregoing embodiments, the second embodiment, or the fifth embodiment, and the beneficial effects are similar to those of the foregoing embodiment, and details are not described herein again.

Embodiment 8 of the present invention also provides a site. FIG. 10 is a schematic structural diagram of a station according to Embodiment 8 of the present invention. The station of the eighth embodiment can perform the calculation method of the phase deviation provided by the third embodiment or the fourth embodiment. As shown in FIG. 10, the site 1000 can include: a generating module 1001 and a sending module 1002.

a generating module 1001, configured to generate a pilot signal according to a pilot model of the station, where a frequency of a pilot model of the station is offset from a phase deviation of the station, different from a frequency pair of pilot models of other stations The offset caused by the phase deviation of the other site; the other site is a site outside the site in the WLAN.

The sending module 1002 is configured to send the generated pilot signal.

Optionally, the pilot model of the site is

Optionally, the site 1000 further includes:

The receiving module is configured to receive, before the generating module 1001 generates a pilot signal according to the pilot model of the station, a pilot model of the station allocated by the access point.

The station of the eighth embodiment of the present invention can perform the calculation method of the phase deviation provided by the third embodiment or the fourth embodiment, and the beneficial effects are similar to those of the foregoing embodiment, and details are not described herein again.

Embodiment 9 of the present invention provides an access point. The access point of the ninth embodiment of the present invention can perform the phase deviation calculation method of the first embodiment, the second embodiment or the fifth embodiment. FIG. 11 is a schematic structural diagram of an access point according to Embodiment 9 of the present invention. As shown in FIG. 11, the access point 1100 includes: a receiver. 1101, a processor 1102 and a transmitter 1103.

The processor 1102 is configured to determine a frequency domain sequence of the mixed pilot sequence, and extract a subsequence corresponding to each site from the frequency domain sequence according to a pilot model of each of the multiple sites, according to the The subsequence corresponding to each station generates a pilot sequence of each station, and the phase deviation of each station is determined according to the pilot sequence of each station.

The hybrid pilot sequence includes a pilot sequence of a plurality of stations; the frequency of the pilot model of each station generates an offset of the phase deviation of each station, and is different from the frequency of the pilot model of other stations. An offset from the phase offset of the other site; the other site is a site outside of each of the plurality of sites in the wireless local area network.

Optionally, the pilot model of each site is

Optionally, the processor 1102 is further configured to allocate a pilot model to each of the multiple sites before the processor 1102 determines the frequency domain sequence of the mixed pilot sequence.

The transmitter 1103 is configured to separately send pilot models of the multiple sites to the multiple sites.

The access point of the ninth embodiment of the present invention can be used in the phase deviation calculation method of any one of the first embodiment, the second embodiment, or the fifth embodiment, and the beneficial effects are similar to those of the foregoing embodiment, and details are not described herein again.

Embodiment 10 of the present invention also provides a site. FIG. 12 is a schematic structural diagram of a station according to Embodiment 10 of the present invention. The station of the tenth embodiment can perform the calculation method of the phase deviation provided in the third embodiment or the fourth embodiment. As shown in FIG. 12, the site 1200 can include a receiver 1201, a processor 1202, and a transmitter 1203.

The processor 1202 is configured to generate a pilot signal according to a pilot model of the station, where a frequency of a pilot model of the station is offset from a phase deviation of the station, different from a pilot model of another station. The offset of the frequency from the phase offset of the other site; the other site is the site outside the site in the WLAN.

The transmitter 1203 is configured to send the generated pilot signal.

Optionally, the pilot model of the site is

Optionally, the receiver 1201 is configured to generate, according to the pilot model of the station, by the processor 1202. Before the pilot signal, the pilot model of the station allocated by the access point is received.

The station of the tenth embodiment of the present invention can perform the calculation method of the phase deviation provided by the third embodiment or the fourth embodiment, and the beneficial effects are similar to those of the foregoing embodiment, and details are not described herein again.

A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to the program instructions. The foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The foregoing steps include the steps of the foregoing method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

A phase deviation calculation method, comprising:

An access point determines a frequency domain sequence of the hybrid pilot sequence, wherein the hybrid pilot sequence includes pilot sequences of a plurality of stations;

And the access point extracts, according to a pilot model of each of the multiple sites, a subsequence corresponding to each of the sites from the frequency domain sequence; wherein, a frequency of a pilot model of each of the sites The offset generated by the phase deviation of each of the stations is different from the offset of the frequency of the pilot models of other stations to the phase deviation of the other stations; the other stations are the plurality of wireless local area networks Sites outside each site described in the site;

Generating, by the access point, a pilot sequence of each site according to a subsequence corresponding to each site;

The access point determines a phase offset of each of the stations based on a pilot sequence of each of the stations.
The method of claim 1 wherein said pilot model for each of said stations is
l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant, Δ is the frequency of the pilot model of each station, and L is the time domain sampling length.
The method according to claim 1 or 2, wherein before the determining, by the access point, the frequency domain sequence of the mixed pilot sequence, the method further comprises:

The access point allocates a pilot model to each of the multiple sites;

The access point transmits a pilot model assigned to the plurality of sites to the plurality of sites, respectively.
A phase deviation calculation method, comprising:

Generating, by the station, a pilot signal according to a pilot model of the station, wherein a frequency of a pilot model of the station produces an offset from a phase deviation of the station, different from a frequency of a pilot model of another station Offset due to phase deviation of other stations; the other stations are sites outside the site in the WLAN;

The station transmits the generated pilot signal.
The method of claim 4 wherein the pilot model of the station is
l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant; Δ is the frequency of the pilot model of the station, and L is the time domain sampling length.
The method according to claim 4 or 5, wherein before the station generates a pilot signal according to the pilot model of the station, the method further includes:

The station receives a pilot model of the station assigned by an access point.
An access point, comprising:

a determining module, configured to determine a frequency domain sequence of the mixed pilot sequence, wherein the mixed pilot sequence includes a pilot sequence of a plurality of stations;

And an extracting module, configured to extract a subsequence corresponding to each of the sites from the frequency domain sequence according to a pilot model of each of the multiple sites; wherein, a frequency of a pilot model of each site The offset generated by the phase deviation of each of the stations is different from the offset of the frequency of the pilot models of other stations to the phase deviation of the other stations; the other stations are the plurality of wireless local area networks Sites outside each site described in the site;

a generating module, configured to generate, according to the sub-sequence corresponding to each station, a pilot sequence of each station;

The determining module is further configured to determine a phase deviation of each of the stations according to a pilot sequence of each of the stations.
The access point of claim 7 wherein said pilot model for each of said stations is
l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant, Δ is the frequency of the pilot model of each station, and L is the time domain sampling length.
The access point according to claim 7 or claim, wherein the access point further comprises:

An allocating module, configured to allocate a pilot model to each of the plurality of stations before the determining module determines the frequency domain sequence of the mixed pilot sequence;

And a sending module, configured to separately send a pilot model allocated to the multiple sites to the multiple sites.
A site characterized by comprising:

Generating a module, configured to generate a pilot signal according to a pilot model of the station, where a frequency of a pilot model of the station generates an offset from a phase deviation of the station, different from a pilot model of another station An offset of the frequency deviation from the phase deviation of the other stations; the other site is a site outside the site in the wireless local area network;

A sending module, configured to send the generated pilot signal.
The station of claim 10 wherein the pilot model of the station is
l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant; Δ is the frequency of the pilot model of the station, and L is the time domain sampling length.
The site according to claim 10 or 11, wherein the site further comprises:

And a receiving module, configured to receive, before the generating module generates a pilot signal according to the pilot model of the station, a pilot model of the station allocated by the access point.
An access point, comprising: a receiver, a processor, and a transmitter;

The processor is configured to determine a frequency domain sequence of the mixed pilot sequence, and extract a subsequence corresponding to each site from the frequency domain sequence according to a pilot model of each of the multiple sites. Generating, according to the sub-sequence corresponding to each station, a pilot sequence of each station, and determining a phase deviation of each station according to a pilot sequence of each station;

The hybrid pilot sequence includes a pilot sequence of a plurality of stations; a frequency of a pilot model of each of the stations produces an offset from a phase offset of each of the stations, different from pilots of other stations. The frequency of the model is offset from the phase deviation of the other stations; the other stations are stations outside each of the plurality of stations in the wireless local area network.
The access point of claim 13 wherein said pilot model for each of said stations is
l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant, Δ is the frequency of the pilot model of each station, and L is the time domain sampling length.
An access point according to claim 13 or 14, characterized in that

The processor is further configured to allocate a pilot model to each of the multiple sites before the processor determines the frequency domain sequence of the mixed pilot sequence;

The transmitter is configured to separately send pilot models of the multiple sites to the multiple sites.
A station, comprising: a receiver, a processor, and a transmitter;

The processor is configured to generate a pilot signal according to a pilot model of the station, where a frequency of a pilot model of the station is offset from a phase deviation of the station, different from that of other stations. The frequency of the pilot model is offset from the phase deviation of the other stations; the other stations are stations outside the station in the wireless local area network;

The transmitter is configured to send the generated pilot signal.
The station of claim 16 wherein the pilot model of the station is
l = 0, 1, ..., L-1, where p is the preset pilot, δ is the preset constant; Δ is the frequency of the pilot model of the station, and L is the time domain sampling length.
A station according to claim 16 or 17, wherein

The receiver is configured to receive, before the processor generates a pilot signal according to the pilot model of the station, a pilot model of the station allocated by an access point.