WO2016074233A1 - 无线局域网中处理信号的方法、站点和接入点 - Google Patents

无线局域网中处理信号的方法、站点和接入点 Download PDF

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Publication number
WO2016074233A1
WO2016074233A1 PCT/CN2014/091160 CN2014091160W WO2016074233A1 WO 2016074233 A1 WO2016074233 A1 WO 2016074233A1 CN 2014091160 W CN2014091160 W CN 2014091160W WO 2016074233 A1 WO2016074233 A1 WO 2016074233A1
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station
pilot signal
ofdm symbol
subcarrier
phase
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PCT/CN2014/091160
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English (en)
French (fr)
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吴涛
陈特彦
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华为技术有限公司
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Priority to PCT/CN2014/091160 priority Critical patent/WO2016074233A1/zh
Publication of WO2016074233A1 publication Critical patent/WO2016074233A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes

Definitions

  • Embodiments of the present invention relate to the field of communications, and, more particularly, to a method, station, and access point for processing signals in a wireless local area network.
  • the wireless local area network (such as WiFi or WLAN) system is also the 802.11 system of the Institute of Electrical and Electronic Engineers (IEEE), which has passed 802.11a, 802.11b, 802.11d, 802.11n and 802.11ac and other technologies.
  • IEEE Institute of Electrical and Electronic Engineers
  • the development is becoming more and more mature, and the system transmission speed is also increasing.
  • the WiFi system will consider introducing Multi User Multiple Input Multiple Output (MU-MIMO) technology in the future.
  • MU-MIMO Multi User Multiple Input Multiple Output
  • the introduction of the uplink MU-MIMO technology is also to solve the problem.
  • the problem of the number of antennas on both sides of the link is asymmetrical.
  • the uplink MU-MIMO technology multiple stations can simultaneously transmit data to an access point (AP). At this time, each user who simultaneously transmits data needs to be synchronized with the frequency in time.
  • AP access point
  • the access point AP can use the Short Training Field ("STF") to achieve frequency synchronization between the AP and the transmitter, it is impossible to achieve completeness due to the influence of noise and interference.
  • STF Short Training Field
  • the frequency is synchronized and will exist as a residual frequency deviation.
  • the presence of a residual frequency deviation causes a phase shift in the received signal.
  • the received signal when there is a frequency deviation can be expressed as follows:
  • h is the channel estimation result obtained by using the Long Training Field (LTF)
  • j is the imaginary unit
  • ⁇ is the frequency deviation due to residual frequency offset and phase noise
  • n is noise.
  • the received signal at this time can be expressed as:
  • the invention provides a method, a station and an access point for processing signals in a wireless local area network, which can reduce the bit error rate of data signal analysis and thereby enhance the receiving performance of the system.
  • a method for processing a signal in a wireless local area network comprising: generating M OFDM symbols for transmitting a pilot signal, and phase compensated OFDM symbols for transmitting a phase compensated pilot signal, M is the number of stations in which the station is located, and the phase compensated pilot signal in the phase compensated OFDM symbol satisfies the following formula (1):
  • p m (k) represents the phase compensated pilot signal of the station on the kth subcarrier
  • p 0 is a constant
  • k represents the sequence number of the subcarrier of the phase compensated OFDM symbol
  • ⁇ m represents the phase offset of the station Transmitting a coefficient
  • the number of subcarriers, m, k, and N take an integer, k 0 is the starting position of the subcarrier, mod(a, b) represents the a/b remainder; and the phase compensated OFDM symbol is determined, the phase compensated OFDM symbol
  • the phase compensated pilot signal of the station is carried on the kth subcarrier
  • the generating the M OFDM symbols for transmitting the pilot signal, and the phase compensation OFDM symbol for transmitting the phase compensation pilot signal including Determining, by the M OFDM symbols, a pilot signal carrying a station on a kth subcarrier of the ith OFDM symbol, wherein the kth subcarrier is in a first group of subcarriers,
  • m represents the serial number of the station, 1 ⁇ m ⁇ M, k 0 ⁇ k ⁇ N-1, and
  • N represents the mth OFDM symbol
  • the number of subcarriers, l, m, k, and N are integers,
  • L is an integer greater than or equal to 2
  • k mod (k 0 + (m-1) L + lML + (z-1) L + x, N)
  • x takes an integer
  • z takes an integer
  • l takes an integer
  • k 0 is the starting position of the subcarrier
  • mod(a, b) represents the remainder of a/b.
  • a second aspect provides a method for processing a signal in a wireless local area network, the method comprising: determining channel response information of a channel through which a station transmits a data signal; determining an estimated frequency deviation of the station according to the channel response information; and receiving The data signal transmitted by the station on the channel; the data signal is parsed according to the channel response information and the frequency offset estimation value.
  • the method further includes: determining a phase compensation channel response information of a channel through which the station transmits a phase compensation pilot signal; Determining the frequency deviation estimation value of the station, comprising: determining the frequency deviation estimation value of the station according to the channel response information and the phase compensation channel response information.
  • the method further includes: determining, by the station, M OFDM symbols for transmitting a pilot signal, and Transmitting a phase compensated pilot signal with a phase compensated OFDM symbol, where M is the number of stations of the station where the station is located; and determining channel response information of the channel through which the data signal is transmitted by the station, including: according to the M OFDM symbols The i-th OFDM symbol, the channel response information of the channel through which the station transmits the pilot signal in the i-th OFDM symbol is determined as the i-th channel response information, i takes a positive integer, 1 ⁇ i ⁇ M; Determining phase compensation channel response information of the channel through which the station transmits the phase compensation pilot signal, including: determining, according to the phase compensated OFDM symbol, a channel through which the station transmits the phase compensated pilot signal in the phase compensated OFDM symbol The phase compensation channel response information; determining the frequency deviation estimation value of the station according to
  • the frequency deviation estimation value includes: determining M frequency deviation estimation values of the station according to the M channel response information of the station and the phase compensation channel response information;
  • the average of the M frequency offset estimates for the station is the frequency offset estimate for the station.
  • the determining that the station is configured to send a pilot signal M OFDM symbols, and phase compensated OFDM symbols for transmitting a phase compensated pilot signal comprising: determining the phase compensated OFDM symbol, the phase compensated pilot signal in the phase compensated OFDM symbol of the station satisfies a formula ( 1):
  • p m (k) represents the phase compensated pilot signal of the station on the kth subcarrier
  • p 0 is a constant
  • k represents the sequence number of the subcarrier of the phase compensated OFDM symbol
  • ⁇ m represents the phase offset of the station Shift coefficient
  • the determining, by the station, the M OFDM symbols used for transmitting the pilot signal, and The phase compensated OFDM symbol for transmitting the phase compensated pilot signal includes: determining the M OFDM symbols, the pilot signal in the M OFDM symbols satisfying formula (1), where p m (k) indicates that the station is The pilot signal on the kth subcarrier, p 0 is a constant, k represents the sequence number of the subcarrier of the OFDM symbol, and ⁇ m represents the phase offset coefficient of the station.
  • the channel response information and the phase compensation is used to determine the frequency deviation estimate of the station, including: determining the frequency offset estimate of the station according to the following formula (2):
  • ⁇ F m,i represents the i-th frequency offset estimate of the station
  • m represents the sequence number of the station
  • 1 ⁇ m ⁇ M represents the guard interval length of the i-th OFDM symbol
  • N represents the i-th
  • k represents the sequence number of the subcarrier occupied by the station in the ith OFDM symbol
  • k 0 ⁇ k ⁇ N-1 k ⁇ K im indicates that k is taken at the site respectively
  • the sequence number of the subcarrier occupied in the i-th OFDM symbol, mean ⁇ indicates averaging
  • angle() indicates phase
  • Hm ,i (k) indicates ith channel response information of the station
  • Hm , M+1 (k) represents the phase compensation channel response information of the station
  • the i-th OFDM symbol the channel response information of the channel through which the pilot signal of the i-th OFDM symbol is transmitted is determined as the i-th channel response information, including: determining the M OFDM symbols sent by the station a received pilot signal in the i-th OFDM symbol; determining the i-th channel response information of the station according to the i-th preset pilot signal and the received pilot signal in the i-th OFDM symbol;
  • the phase compensated OFDM symbol determining the phase compensation channel response information of the channel through which the station transmits the phase compensated pilot signal in the phase compensated OFDM symbol, comprising: determining the phase in the phase compensated OFDM symbol transmitted by the station Compensating the pilot signal; determining the phase compensation channel response information of the station according to the preset phase compensation pilot signal and the phase compensation pilot signal.
  • the determining the phase compensation pilot signal in the phase compensated OFDM symbol sent by the station includes: : receiving a pilot signal in a phase compensated OFDM symbol transmitted by multiple stations; performing an inverse Fourier transform IDFT on the pilot signal to determine a first pilot signal; and performing filtering processing on the first pilot signal to determine a second pilot signal; the second pilot signal is subjected to Fourier Transforming the DFT to determine a third pilot signal; determining, according to the third pilot signal, the phase compensated pilot signal in the phase compensated OFDM symbol transmitted by the station.
  • a station in a wireless local area network comprising: a generating module, configured to generate M OFDM symbols for transmitting a pilot signal, and phase compensated OFDM for transmitting a phase compensated pilot signal Symbol, the number of stations of the group where the station is located, the phase compensated pilot signal in the phase compensated OFDM symbol satisfies the following formula (1):
  • p m (k) represents the phase compensated pilot signal of the station on the kth subcarrier
  • p 0 is a constant
  • k represents the sequence number of the subcarrier of the phase compensated OFDM symbol
  • ⁇ m represents the phase offset of the station a transmission coefficient, configured to send the M OFDM symbols including the pilot signal to an access point, and the phase compensated OFDM symbol including the phase compensated pilot signal, so that the access point determines the frequency offset estimation value.
  • the generating module is specifically configured to: determine the M OFDM symbols, the kth of the ith OFDM symbols in the M OFDM symbols
  • N represents the number of subcarriers in the mth OFDM symbol, m, k and N are integers, and k 0 is the starting position of the subcarrier, Mod(a,b) denotes a/b remainder; the phase compensated OFDM symbol is determined, and the phase compensated pilot signal of the station is carried on the kth subcarrier in the phase compensated OFDM symbol, where k 0 ⁇ k ⁇ N-1, k 0 is the starting position of the subcarrier.
  • k 0 is the starting position of the subcarrier, mod(a, b) represents the a/b remainder; the phase compensated OFDM symbol is determined, the phase compensates for the kth subcarrier in the OFDM symbol Carrying the phase compensated pilot signal of the station, ,
  • the k-th subcarrier in the first set of subcarriers l which comprises a first set of subcarriers l L sub-carriers, L is an integer greater than or equal to 2
  • k mod (k 0 + m-1 + xM + z- 1, N), 1 ⁇ z ⁇ M, z takes an integer, 0 ⁇ x ⁇ L, x takes an integer, 0 ⁇ l ⁇ N / (L * M), l takes an integer, k 0 is the starting position of the subcarrier , mod(a,b) represents the remainder of a/b.
  • a fourth aspect provides an access point in a wireless local area network, where the access point includes: a first determining module, configured to determine channel response information of a channel through which a station transmits a data signal; and a second determining module, configured to: Determining an estimated frequency deviation of the station according to the channel response information; receiving mode And a processing module, configured to parse the data signal according to the channel response information and the frequency offset estimation value.
  • the first determining module is further configured to: determine a phase compensation channel response information of a channel through which the station transmits a phase compensation pilot signal;
  • the determining module is specifically configured to: determine the frequency offset estimation value of the station according to the channel response information and the phase compensation channel response information.
  • the first determining module is specifically configured to: determine, by the station, M OFDM symbols for transmitting a pilot signal And a phase-compensated OFDM symbol for transmitting a phase-compensated pilot signal, where M is the number of stations of the station where the station is located; and transmitting the i-th station according to the i-th OFDM symbol of the M OFDM symbols
  • the channel response information of the channel through which the pilot signal in the OFDM symbol passes is determined as the i-th channel response information, i takes a positive integer, 1 ⁇ i ⁇ M; according to the phase compensated OFDM symbol, it is determined that the station transmits the phase compensation
  • the second determining module is specifically configured to: determine, according to the ith channel response information of the station and the phase compensation channel response information, The frequency deviation estimate for the site.
  • the second determining module is specifically configured to: according to the M channel response information of the station and the phase compensation channel Responding to the information, determining M frequency deviation estimation values of the station; determining an average of the M frequency deviation estimation values of the station as the frequency deviation estimation value of the station.
  • the first determining module is specifically configured to: determine The phase compensates for the OFDM symbol, and the phase compensated pilot signal in the phase compensated OFDM symbol of the station satisfies equation (1):
  • p m (k) represents the phase compensated pilot signal of the station on the kth subcarrier
  • p 0 is a constant
  • k represents the sequence number of the subcarrier of the phase compensated OFDM symbol
  • ⁇ m represents the phase offset of the station Shift coefficient
  • the first determining module is specifically configured to: determine the M OFDM symbols, the M The pilot signal in the OFDM symbol satisfies the formula (1), wherein p m (k) represents the pilot signal of the station on the kth subcarrier, p 0 is a constant, and k represents a subcarrier of the OFDM symbol number, ⁇ m represents the phase shift coefficient of the site.
  • the second determining module is specifically configured to: Equation (2) below determines the frequency deviation estimate for the site:
  • ⁇ F m,i represents the i-th frequency offset estimate of the station
  • m represents the sequence number of the station
  • 1 ⁇ m ⁇ M represents the guard interval length of the i-th OFDM symbol
  • N represents the i-th
  • k represents the sequence number of the subcarrier occupied by the station in the ith OFDM symbol
  • k 0 ⁇ k ⁇ N-1 k ⁇ K im indicates that k is taken at the site respectively
  • the sequence number of the subcarrier occupied in the i-th OFDM symbol, mean ⁇ indicates averaging
  • angle() indicates phase
  • Hm ,i (k) indicates ith channel response information of the station
  • Hm , M+1 (k) represents the phase compensation channel response information of the station
  • the first determining module is specifically configured to: Determining a received pilot signal in an ith OFDM symbol of the M OFDM symbols sent by the station; and receiving a pilot signal according to the ith preset pilot signal and the ith OFDM symbol Determining the ith channel response information of the station; determining the phase compensated pilot signal in the phase compensated OFDM symbol sent by the station; determining the pilot signal according to the preset phase compensation pilot signal and the phase compensation pilot signal This phase of the station compensates for channel response information.
  • the first determining module is specifically configured to: receive, in a phase compensated OFDM symbol sent by multiple stations a pilot signal; performing an inverse Fourier transform IDFT on the pilot signal to determine a first pilot signal; performing a filtering process on the first pilot signal to determine a second pilot signal; and performing the second pilot signal And performing a Fourier transform DFT to determine a third pilot signal; and determining, according to the third pilot signal, the phase compensated pilot signal in the phase compensated OFDM symbol transmitted by the station.
  • a method, a station, and an access point for processing a signal in a wireless local area network determine a frequency deviation estimation value of the station by determining channel response information of a channel used by the station to transmit a data signal, according to the The channel response information and the frequency deviation estimation value, thereby analyzing the received data signal, can avoid the influence of the frequency deviation between the multiple stations, so that the parsed data signal is more accurate, and the error rate of the data signal analysis is reduced, thereby further Enhanced system reception performance.
  • FIG. 1 is a schematic diagram of a deployment scenario of a wireless local area network to which an embodiment of the present invention is applicable.
  • FIG. 1b is a schematic flowchart of a method of processing a signal in a wireless local area network according to an embodiment of the present invention.
  • FIG. 2 is a schematic flow chart of a method of processing a signal in a wireless local area network according to an embodiment of the present invention.
  • FIG. 3 is another schematic flowchart of a method of processing a signal in a wireless local area network according to an embodiment of the present invention.
  • FIG. 4 is a schematic diagram of an OFDM symbol arrangement in accordance with an embodiment of the present invention.
  • FIG. 5 is another schematic diagram of an OFDM symbol arrangement according to an embodiment of the present invention.
  • FIG. 6 is still another schematic diagram of an OFDM symbol arrangement according to an embodiment of the present invention.
  • FIG. 7 is still another schematic diagram of an OFDM symbol arrangement according to an embodiment of the present invention.
  • FIG. 8 is a schematic block diagram of a station in a wireless local area network in accordance with an embodiment of the present invention.
  • FIG. 9 is a schematic block diagram of an access point in a wireless local area network in accordance with an embodiment of the present invention.
  • FIG. 10 is another schematic block diagram of a station in a wireless local area network in accordance with an embodiment of the present invention.
  • FIG. 11 is another schematic block diagram of an access point in a wireless local area network in accordance with an embodiment of the present invention.
  • FIG. 1a is a simplified schematic diagram of a WLAN system according to an embodiment of the present invention.
  • the system of Figure 1a includes one or more access points AP 101 and one or more stations STA 102, with Figure 1a taking one access point and two sites as an example.
  • MU-MIMO technology can be used for wireless communication between the access point 101 and the station 102.
  • An Access Point which can also be called a wireless access point or bridge or hotspot, can access a server or a communication network.
  • a station 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 a computer with wireless communication function.
  • a mobile terminal such as a mobile phone (or "cellular" phone) that supports WiFi communication function and a computer with wireless communication function.
  • 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.
  • 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.
  • FIG. 1b shows a schematic flow chart of a method of processing a signal in a wireless local area network according to an embodiment of the present invention.
  • a station sends a frame structure including a data signal to an AP.
  • the AP synchronizes with the STF of the local AP and the received data signal, thereby implementing symbol synchronization and frequency synchronization.
  • OFDM Orthogonal Frequency Division Multiplexing
  • the AP performs channel estimation using the received Long Training Field (LTF) to obtain channel information.
  • LTF Long Training Field
  • the AP needs to obtain LTF before processing the data.
  • the channel estimation information equalizes the received frequency domain data to eliminate the influence of the channel; due to the influence of phase noise and residual frequency offset, the channel equalized data is still affected by the frequency deviation, and the AP also needs to have the frequency deviation. Make compensation. After the compensation is performed based on the result of the channel estimation and the frequency deviation, the data signal is subjected to processing such as decoding and demodulation to obtain a data stream.
  • an embodiment of the present invention provides a method, a station, and an access point for processing a signal in a wireless local area network, and the frequency deviation estimation value is calculated to eliminate the influence of the frequency deviation.
  • the method 100 includes:
  • phase compensated pilot signal satisfies the following formula (1):
  • p m (k) represents the phase compensated pilot signal of the station on the kth subcarrier
  • p 0 is a constant
  • k represents the sequence number of the subcarrier of the phase compensated OFDM symbol
  • ⁇ m represents the phase offset of the station Shift coefficient
  • a station transmits an OFDM symbol including a pilot signal to an AP, and the AP determines a frequency of the station by determining channel response information of a channel through which the station transmits the pilot signal.
  • the deviation estimation value according to the channel response information and the frequency deviation estimation value, the AP parses the received data signal, thereby avoiding the influence of the frequency deviation between the multiple stations, so that the parsed data signal is more accurate, and the data signal analysis is reduced.
  • the bit error rate which in turn enhances the reception performance of the system.
  • the station In S110, the station generates M OFDM symbols for transmitting pilot signals, and phase compensated OFDM symbols for transmitting phase compensated pilot signals.
  • M OFDM symbols, and phase compensated OFDM symbols may be multiplexed by subcarrier interleaving.
  • the number of subcarriers in the OFDM symbol, m, k, and N take an integer
  • k 0 is the starting position of the subcarrier
  • mod(a, b) represents the a/b remainder.
  • the station may carry the pilot signal transmitted by the station on the kth subcarrier in the phase compensated OFDM symbol, where k 0 ⁇ k ⁇ N-1.
  • the M OFDM symbols, and the phase compensated OFDM symbols may also be multiplexed by means of block interleaving.
  • the pilot signal that the station needs to transmit is carried on the kth subcarrier in the i th OFDM symbol, where the kth subcarrier is in the first group of subcarriers.
  • the station may carry the pilot signal transmitted by the station on the kth subcarrier in the phase compensated OFDM symbol, k 0 ⁇ k ⁇ N-1.
  • the pilot signal of the station may be carried on the kth subcarrier in the phase compensated OFDM symbol, where the kth subcarrier is in the first group of subcarriers, and the first group of subcarriers includes L subcarriers.
  • k mod(k 0 +(m-1)L+lML+(z-1)L+x,N),1 ⁇ z ⁇ M,z takes an integer, 0 ⁇ x ⁇ L, x takes an integer, 0 ⁇ l ⁇ N / (L * M), L is an integer greater than or equal to 2, and the pilot signal in the M OFDM symbols used by the station for transmitting the pilot signal satisfies the formula (1), where p m (k) The pilot signal representing the station on the kth subcarrier, p 0 is a constant, k represents the sequence number of the subcarrier of the OFDM symbol, and ⁇ m represents the phase offset coefficient of the station.
  • the phase-compensated OFDM symbols generated by the station may be multiplexed by cyclic shift (CSD), that is, the phase-compensated pilot signals transmitted by different stations and the preset phase-compensated pilot signals are different in different subframes.
  • CSD cyclic shift
  • Equation (1) is satisfied on the carrier, where p m (k) represents the phase compensated pilot signal or the preset phase compensated pilot signal of the station on the kth subcarrier, p 0 is a constant, and k represents the phase compensated OFDM subcarrier symbol number, as shown in [Delta]
  • M represents the number of stations of the group in which the station is located.
  • the sites within the group in which the site is located may belong to the same AP or base station.
  • the station sends the generated M OFDM symbols including the pilot signal to the AP, and the phase compensated OFDM symbol including the phase compensated pilot signal, so that the AP determines the channel according to the pilot signal and the phase compensated pilot signal.
  • Corresponding information, and the frequency deviation estimation value is determined according to the corresponding information of the channel.
  • the size of the sequence numbers of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not be taken to the embodiments of the present invention.
  • the implementation process constitutes any limitation.
  • a station transmits an OFDM symbol including a pilot signal to an AP, and the AP determines a frequency offset of the station by determining channel response information of a channel through which the station transmits the pilot signal.
  • the estimated value according to the channel response information and the frequency deviation estimation value, the AP parses the received data signal, thereby avoiding the influence of the frequency deviation between the multiple stations, so that the parsed data signal is more accurate, and the data signal analysis is reduced.
  • the bit error rate which in turn enhances the reception performance of the system.
  • FIG. 3 shows a schematic flow diagram of a method 200 of processing a signal in a wireless local area network, which may be performed by an access point AP, in accordance with an embodiment of the present invention.
  • the method 200 includes:
  • S220 Determine, according to the channel response information, an estimated frequency deviation of the station.
  • the AP determines channel response information of the channel through which the station sends the data signal, and determines an estimated frequency deviation of the station according to the channel response information, according to the channel response information and frequency.
  • the estimated value of the deviation is used to parse the received data signal sent by the station, thereby obtaining the original data signal sent by the near station.
  • the method for processing a signal in a wireless local area network is determined by determining a site.
  • the channel response information of the channel through which the data signal is sent is used to determine the frequency deviation estimation value of the station, and the received data signal is parsed according to the channel response information and the frequency deviation estimation value, thereby avoiding frequency deviation between multiple stations.
  • the impact of the parsed data signal is more accurate, reducing the bit error rate of the data signal parsing, thereby enhancing the receiving performance of the system.
  • the AP determines channel response information that the channel through which the station transmits the data signal passes. Specifically, the AP determines an OFDM symbol carrying a pilot signal transmitted by the station, obtains a pilot signal according to the OFDM symbol, and determines channel response information of the station according to the pilot signal.
  • the station transmits M OFDM symbols, and the phase compensates OFDM symbols, where M is the number of stations in which the station is located.
  • the M OFDM symbols may be multiplexed by means of subcarrier interleaving, that is, for the M OFDM symbols transmitted by the mth station, the station needs to be sent on the kth subcarrier in the ith OFDM symbol.
  • the AP determines a pilot signal carried on M OFDM symbols transmitted by the mth station.
  • the pilot signal on the kth subcarrier in the ith OFDM symbol can be directly received as the pilot signal of the mth station on the kth subcarrier.
  • the ith OFDM symbol may be separated to obtain a pilot signal of the mth station on the kth subcarrier.
  • the AP simultaneously receives the pilot signals sent by the multiple stations, performs an inverse Fourier transform IDFT on the pilot signals, performs filtering processing on the transformed pilot signals, and finally performs Fourier transform on the pilot signals. Transforming the DFT to obtain the pilot signals of different stations, and the pilot signals of different stations are separated from each other, and the pilot signals of the respective stations are separated to obtain the mth station on the kth subcarrier. Pilot signal.
  • the AP determines the channel response information of the station according to the comparison between the preset pilot signal and the received pilot signal.
  • the mth channel may be determined according to the received pilot signal of the mth station on the ith OFDM symbol and the pilot signal preset by the station on the OFDM symbol by using the following formula (2)
  • the i-th channel response information of the station is the following formula (2)
  • r m (k) represents the pilot signal transmitted by the received mth station on the kth subcarrier on the ith OFDM symbol
  • P m (k) represents the mth station at the ith OFDM symbol
  • H m (k) represents the i th channel response information of the mth station on the kth subcarrier.
  • the AP determines an estimated frequency deviation of the station according to the channel response information. Specifically, the AP may first determine the phase compensation channel response information of the channel used by the station to transmit the phase compensation pilot signal, and determine the frequency offset estimation value of the station according to the channel response information and the phase compensation channel response information.
  • the station transmits M OFDM symbols, and the phase compensates OFDM symbols, where M is the number of stations in which the station is located.
  • M is the number of stations in which the station is located.
  • the pilot signal that the station needs to transmit is carried on the kth subcarrier in the i th OFDM symbol.
  • the pilot signal transmitted by the station may be carried on each subcarrier in the phase compensated OFDM symbol, or may be carried on the kth subcarrier in the phase compensated OFDM symbol.
  • the pilot signal of the station may be carried on each subcarrier in the phase compensated OFDM symbol, or may be carried on the kth subcarrier in the phase compensated OFDM symbol.
  • the site of the pilot signal multiplexed subcarrier interleaved manner or in a block interleaving manner when multiplexing sites on the subsequent phase compensation OFDM symbol of k 0 th subcarrier of each subcarrier carries the The pilot signal of the station
  • the kth subcarrier carrying the pilot signal satisfies k 0 ⁇ k ⁇ N-1.
  • N 1 ⁇ m ⁇ M, k 0 ⁇ k ⁇ N-1, N represents the number of subcarriers in the mth OFDM symbol, m, k and N are integers, k 0 is the starting position of the subcarrier, mod (a, b) indicates that a/b takes the remainder.
  • the pilot signal in the M OFDM symbols used by the station for transmitting the pilot signal satisfies the formula (1), where p m (k) represents the pilot signal of the station on the kth subcarrier, p 0 Is a constant, k represents the sequence number of the subcarrier of the OFDM symbol, and ⁇ m represents the phase offset coefficient of the station.
  • the phase compensated OFDM symbols are multiplexed by means of CSD, and the preset phase compensated pilot signals of different stations satisfy the formula (1) on different subcarriers, wherein p m (k) represents the station.
  • the preset phase compensated pilot signal on the kth subcarrier, p 0 is a constant, k represents the sequence number of the subcarrier of the phase compensated OFDM symbol, and ⁇ m represents the phase offset coefficient of the mth station shown, Ground selection, ⁇ m CP ⁇ m.
  • the AP determines a phase compensated pilot signal of the phase compensated OFDM symbol. Specifically, when each subcarrier in the phase compensated OFDM symbol carries a phase compensated pilot signal, the phase compensated pilot signal received by the AP on each subcarrier is a phase compensated pilot signal belonging to multiple stations. Superimposed, the pilot signals of each station on each subcarrier can be determined separately by separation. When the station only carries the phase compensation pilot information on the kth subcarrier in the phase compensated OFDM symbol, after the AP receives the CSD multiplexing mode, each subcarrier carries the phase pilot symbols of different stations, and the same can be The pilot signals on each subcarrier are separated by a separate method to obtain a more accurate phase compensation pilot signal.
  • the separation of the pilot signals can be performed by the following method. Performing an inverse Fourier transform IDFT on the phase compensated pilot signal received by the AP to obtain a first pilot signal, and then filtering the first pilot signal to obtain a second pilot signal, and finally the second pilot signal The signal is subjected to Fourier transform DFT to obtain a third pilot signal including phase compensated pilot signals of different stations, and phase compensated pilot signals of different stations are separated from each other, and phase compensation pilot signals of respective stations are separated to obtain A phase compensated pilot signal on the kth subcarrier of the mth station in the phase compensated OFDM symbol.
  • phase compensation channel response information of the mth station may be determined by equation (2), where r m (k) represents the received phase compensated pilot signal of the mth station on the phase compensated OFDM symbol, P m (k) indicates that the station presets a phase compensated pilot signal on the phase compensated OFDM symbol, and H m (k) represents phase compensation channel response information of the mth station.
  • the AP determines the frequency offset estimation value of the station according to the i-th channel response information of the station and the phase compensation channel response information.
  • the frequency deviation estimation value of the station may be determined by determining the i-th channel response information and the phase compensation channel response information of the station, and the site may be determined by the M channel response information and the phase compensation channel response information of the station. M frequency deviation estimation values, and the average value of the M frequency deviation estimation values is determined as the frequency deviation estimation value of the station.
  • the ith frequency deviation estimated value ⁇ F m,i of the mth station can be determined by the following formula (3):
  • m represents the sequence number of the station, 1 ⁇ m ⁇ M
  • CP represents the guard interval length of the i-th OFDM symbol
  • N represents the number of subcarriers in the i-th OFDM symbol
  • k represents the mth site in the
  • Mean ⁇ denotes averaging
  • angle() denotes phase
  • H m,i (k) denotes i-th channel response information of the mth station
  • H m,M+1 (k) denotes mth site
  • the phase compensates for channel response information, Represents the conjugate of H m,M+1 (k).
  • the AP receives the data signal transmitted by the station, and the station transmits the data signal through the channel in S110.
  • the AP analyzes the received data signal according to the channel response information and the frequency offset estimation value, and determines the original data signal sent by the station. Specifically, the AP can parse the data signal according to the following formula (3):
  • r is the data signal sent by the AP received by the AP
  • h is the channel response information of the station
  • s is the analysis result of the data signal, and the result can be determined as the original data signal sent by the station
  • ⁇ is the site data Estimated frequency deviation
  • j is an imaginary unit
  • n is noise. According to this formula, the AP can parse the data signal sent more accurately and closer to the station.
  • the size of the sequence numbers of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not be taken to the embodiments of the present invention.
  • the implementation process constitutes any limitation.
  • the method for processing a signal in a wireless local area network determines a frequency offset estimation value of the station by determining channel response information of a channel used by the station to transmit the data signal, according to the channel response information and the frequency deviation estimation value, Therefore, the received data signal is parsed, the influence of the frequency deviation between the multiple stations can be avoided, the parsed data signal is more accurate, the error rate of the data signal parsing is reduced, and the receiving performance of the system is enhanced.
  • FIG. 2 and FIG. 3 a method for processing signals in a wireless local area network according to an embodiment of the present invention is described in detail from the perspective of an AP.
  • FIG. 4 to FIG. 7 A method of processing a signal in a wireless local area network according to an embodiment of the present invention.
  • FIG. 4 illustrates an OFDM symbol arrangement according to an embodiment of the present invention.
  • the first 4 columns are the OFDM symbols of the 4 stations, the different colors represent the pilot signals of different stations, and the 5th column is the phase compensated OFDM symbols of the 4 stations.
  • Each OFDM symbol may include multiple subcarriers, and here, 64 subcarriers are taken as an example for description.
  • the AP determines an OFDM symbol used by each station to transmit a pilot signal, and the k-th subcarrier of the i-th OFDM symbol of the mth station carries a pilot signal, and the remaining subcarriers are empty.
  • k mod(k 0 +m-1+xM+i-1,N)
  • x takes an integer
  • k 0 is the starting position of the subcarrier
  • ie k 0 0
  • Mod(a,b) represents the a/b remainder.
  • station 1 does not transmit the pilot.
  • the subcarrier is empty.
  • the four OFDM symbols of the four stations are superimposed to obtain four OFDM symbols as shown in FIG. 4, and one subcarrier on each OFDM symbol carries a pilot signal of one station, according to the pilot signal and the preamble
  • the pilot signals are compared for comparison, and the channel response information of each subcarrier on each OFDM symbol of each station can be obtained by formula (2).
  • each station also sends a phase compensated pilot signal
  • each subcarrier in the phase compensated OFDM symbol carries the phase compensated pilot signal
  • the preset phase compensated pilot signal of each station satisfies Equation (1), multiplexed by CSD mode
  • the AP receives the phase compensated pilot signals of 4 stations, which is the phase compensated pilot signal of each station on 4 subcarriers.
  • the OFDM symbol of the fifth column is obtained as a phase compensated OFDM symbol.
  • the phase-compensated pilot signals of four stations are included in each subcarrier of the phase-compensated OFDM symbol obtained by the AP, and the received pilot is needed in order to obtain the phase-compensated pilot signal of each station.
  • the signal is separated.
  • the received phase compensated pilot signal is subjected to inverse Fourier transform IDFT, and then subjected to filtering processing, and then subjected to Fourier transform DFT to obtain phase compensated pilot signals of four stations separated from each other.
  • the phase compensation channel response information of each station on the kth subcarrier can be obtained by formula (2).
  • the frequency deviation estimation value of each station relative to each OFDM symbol can be obtained according to formula (3), where m represents the serial number of the station, 1 ⁇ m ⁇ 4, and CP represents the protection of the OFDM symbol.
  • each OFDM symbol for each station can be separately obtained.
  • one of the frequency deviation estimates can be directly used as the level of the station.
  • the rate deviation estimation value may also determine that the average of the four frequency deviation estimation values is the frequency deviation estimation value of the station.
  • the AP respectively determines the frequency deviation estimation value of each station, and parses and processes the received data signal of the station according to the frequency deviation estimation value and the channel response information of each station, thereby obtaining the parsed data. signal.
  • the method for processing a signal in a wireless local area network determines a frequency offset estimation value of the station by determining channel response information of a channel used by the station to transmit the data signal, according to the channel response information and the frequency deviation estimation value, Therefore, the received data signal is parsed, the influence of the frequency deviation between the multiple stations can be avoided, the parsed data signal is more accurate, the error rate of the data signal parsing is reduced, and the receiving performance of the system is enhanced.
  • FIG. 5 shows an OFDM symbol arrangement according to an embodiment of the present invention. Another schematic. The first 4 columns are the OFDM symbols of the 4 sites, and the different colors represent The pilot signals of different stations are used; the fifth column is the phase compensated OFDM symbols of the four stations.
  • Each OFDM symbol may include multiple subcarriers. Here, 64 subcarriers are taken as an example, and each of the four subcarriers is a group of 16 subcarriers.
  • the AP determines an OFDM symbol used by each station to transmit a pilot signal
  • the first group of subcarriers of the i th OFDM symbol of the mth station carries a pilot signal
  • the first group of subcarriers includes L subcarriers
  • the subcarrier number is k
  • x takes an integer, 0 ⁇ l ⁇ N / (L * M),
  • L is an integer greater than or equal to 2
  • l is an integer
  • m represents the serial number of the station
  • k 0 is the starting position of the subcarrier
  • k 0 0
  • mod(a,b) indicates that a/b takes the remainder.
  • station 1 does not transmit a pilot signal, and the subcarrier is empty.
  • the four OFDM symbols of the four stations are superimposed to obtain four OFDM symbols as shown in FIG. 5, and each subcarrier group on each OFDM symbol carries a pilot signal of one station, and each subcarrier group includes 4
  • the subcarriers are compared according to the pilot signal and the preset pilot signal, and the channel response information of each subcarrier on each OFDM symbol of each station can be obtained by using formula (2).
  • each station also sends a phase compensated pilot signal
  • each subcarrier in the phase compensated OFDM symbol carries the phase compensated pilot signal
  • the preset phase compensated pilot signal of each station satisfies Equation (1), which is multiplexed by the CSD method
  • the AP receives the phase compensated pilot signals of the four stations, and the result is that the phase compensated pilot signals of the four stations are superimposed on each subcarrier, and the fifth column is obtained.
  • the OFDM symbols are phase compensated OFDM symbols.
  • the phase-compensated pilot signals of four stations are included in each subcarrier of the phase-compensated OFDM symbol obtained by the AP, and the received pilot is needed in order to obtain the phase-compensated pilot signal of each station.
  • the signal is separated.
  • the received phase compensated pilot signal is subjected to inverse Fourier transform IDFT, and then subjected to filtering processing, and then subjected to Fourier transform DFT to obtain phase compensated pilot signals of four stations separated from each other.
  • the phase compensation channel response information of each station on the kth subcarrier can be obtained by formula (2).
  • the frequency deviation estimation value of each station relative to each OFDM symbol can be obtained according to formula (3), where m represents the serial number of the station, 1 ⁇ m ⁇ 4, and CP represents the protection of the OFDM symbol.
  • each OFDM symbol for each station can be separately obtained.
  • one of the frequency deviation estimates can be directly used as the level of the station.
  • the rate deviation estimation value may also determine that the average of the four frequency deviation estimation values is the frequency deviation estimation value of the station.
  • the AP after determining the frequency deviation estimation value of each station, the AP separately parses and processes the received data signal of the station according to the frequency deviation estimation value and the channel response information of each station, thereby obtaining the parsed data. Data signal.
  • the method for processing a signal in a wireless local area network determines a frequency offset estimation value of the station by determining channel response information of a channel used by the station to transmit the data signal, according to the channel response information and the frequency deviation estimation value, Therefore, the received data signal is parsed, the influence of the frequency deviation between the multiple stations can be avoided, the parsed data signal is more accurate, the error rate of the data signal parsing is reduced, and the receiving performance of the system is enhanced.
  • FIG. 6 shows an OFDM symbol arrangement according to an embodiment of the present invention. Another schematic.
  • the first 4 columns are the OFDM symbols of the 4 stations, the 5th column is the phase compensated OFDM symbols of the 4 stations, and the different colors in the OFDM symbols of each column represent the pilot signals carrying different stations on different subcarriers.
  • Each OFDM symbol may include multiple subcarriers, and here, 64 subcarriers are taken as an example for description.
  • the AP determines an OFDM symbol used by each station to transmit a pilot signal, and the k-th subcarrier of the i-th OFDM symbol of the mth station carries a pilot signal, and the remaining subcarriers are empty.
  • station 1 on the remaining subcarriers, station 1 does not transmit the pilot.
  • the subcarrier is empty.
  • the four OFDM symbols of the four stations are superimposed to obtain four OFDM symbols as shown in FIG. 6, and one subcarrier on each OFDM symbol carries a pilot signal of one station.
  • the pilot signal in the M OFDM symbols used by the station for transmitting the pilot signal satisfies the formula (1), where p m (k) represents the pilot signal of the station on the kth subcarrier, p 0 Is a constant, k represents the sequence number of the subcarrier of the OFDM symbol, and ⁇ m represents the phase offset coefficient of the station.
  • the phase compensated pilot signals of the four stations are superimposed, and the OFDM symbols of the fifth column are obtained as phase compensated OFDM symbols.
  • the preset phase compensation pilot signal satisfies the formula (1), and is multiplexed by the CSD method, and the AP receives the phase compensation pilot signals of the four stations.
  • the pilot signal and the phase compensation pilot signal of different stations carried on the different subcarriers of the 4 OFDM symbols obtained by the AP and the 1 phase compensated OFDM symbol are obtained in order to obtain each of the pilot signals more accurately.
  • the pilot signal of the station and the phase compensated pilot signal need to separate the received pilot signal and the phase compensated pilot signal.
  • the received pilot signal or the phase compensated pilot signal on each OFDM symbol is first subjected to inverse Fourier transform IDFT, and then subjected to filtering processing, and then subjected to Fourier transform DFT to obtain each.
  • the pilot signal and the phase compensated pilot signal in the first OFDM symbol of each station obtained according to the separation are passed according to a preset pilot signal and a preset phase compensation pilot signal.
  • Equation (2) obtains channel response information for each station for the kth subcarrier for the 1st OFDM symbol and phase compensation channel response information for the phase compensated OFDM symbol for the kth subcarrier.
  • the sequence number of the occupied subcarrier, k 0 ⁇ k ⁇ N-1, that is, 0 ⁇ k ⁇ 63, k ⁇ K im denotes that k respectively takes the sequence number of the subcarrier occupied by the station in the ith OFDM symbol, mean ⁇ denotes averaging, angle() denotes phase, H m,i (k) denotes the i-th channel response information of the station, and H m,M+1 (k) denotes the phase compensation channel response of the station information,
  • the frequency deviation estimation value of each station for the first OFDM symbol can be separately obtained according to the formula (3), and the frequency deviation estimation value can be determined as the frequency deviation estimation value of the station.
  • the AP respectively determines the frequency deviation estimation value of each station, and parses and processes the received data signal of the station according to the frequency deviation estimation value and the channel response information of each station, thereby obtaining the parsed data. signal.
  • the method for processing a signal in a wireless local area network determines a frequency offset estimation value of the station by determining channel response information of a channel used by the station to transmit the data signal, according to the channel response information and the frequency deviation estimation value, Therefore, the received data signal is parsed, the influence of the frequency deviation between the multiple stations can be avoided, the parsed data signal is more accurate, the error rate of the data signal parsing is reduced, and the receiving performance of the system is enhanced.
  • FIG. 7 shows an OFDM symbol arrangement according to an embodiment of the present invention. Another schematic.
  • the first 4 columns are the OFDM symbols of the 4 stations, the 5th column is the phase compensated OFDM symbols of the 4 stations, and the different colors in the OFDM symbols of each column represent the pilot signals carrying different stations on different subcarriers.
  • Each OFDM symbol may include multiple subcarriers, where 64 subcarriers are taken as an example.
  • Each of the four subcarriers is a group of 16 subcarriers.
  • Each of the different OFDM symbols in FIG. 7 represents a group of subcarriers. 4 subcarriers per group.
  • the AP determines an OFDM symbol used by each station to transmit a pilot signal
  • the first group of subcarriers of the i th OFDM symbol of the mth station carries a pilot signal
  • the first group of subcarriers includes L subcarriers
  • the subcarrier number is k
  • x takes an integer, 0 ⁇ l ⁇ N / (L * M),
  • L is an integer greater than or equal to 2
  • l is an integer
  • m represents the serial number of the station
  • station 1 does not transmit a pilot signal, and the subcarrier is empty.
  • the four OFDM symbols of the four stations are superimposed to obtain four OFDM symbols as shown in FIG. 7.
  • Each subcarrier group on each OFDM symbol carries a pilot signal of one station, and each subcarrier group includes 4 Subcarriers.
  • the pilot signal in the M OFDM symbols used by the station for transmitting the pilot signal satisfies the formula (1), where p m (k) represents the pilot signal of the station on the kth subcarrier, p 0 Is a constant, k represents the sequence number of the subcarrier of the OFDM symbol, and ⁇ m represents the phase offset coefficient of the station.
  • each station also sends a phase compensation pilot signal
  • each of the L-subcarriers in the phase-compensated OFDM symbol carries a pilot signal
  • the L-th sub-carrier includes 1 sub-carrier.
  • k mod(k 0 +(m-1)L+lML+(z-1)L+x,N),1 ⁇ z ⁇ M,z
  • k mod(k 0 +(m-1)L+lML+(z-1)L+x,N)
  • l takes the integer m to indicate the serial number of the site.
  • station 1 does not transmit a phase compensated pilot signal, which is empty.
  • the phase compensated pilot signals of the four stations are superimposed, and the OFDM symbols of the fifth column are obtained as phase compensated OFDM symbols.
  • the preset phase compensation pilot signal satisfies the formula (1), and is multiplexed by the CSD method, and the AP receives the phase compensation pilot signals of the four stations.
  • the pilot signal and the phase compensation pilot signal of different stations carried on the different subcarriers of the 4 OFDM symbols obtained by the AP and the 1 phase compensated OFDM symbol are obtained in order to obtain each of the pilot signals more accurately.
  • the pilot signal of the station and the phase compensated pilot signal need to separate the received pilot signal and the phase compensated pilot signal.
  • the received pilot signal or the phase compensated pilot signal on each OFDM symbol is first subjected to inverse Fourier transform IDFT, and then subjected to filtering processing, and then subjected to Fourier transform DFT to obtain each.
  • the pilot signal is compensated according to the preset pilot signal and the preset phase according to the preset pilot signal.
  • the channel response information of each station for the kth subcarrier for the 1st OFDM symbol and the phase compensation channel response information for the kth subcarrier for the phase compensated OFDM symbol can be obtained by Equation (2).
  • the sequence number of the occupied subcarrier, k 0 ⁇ k ⁇ N-1, that is, 0 ⁇ k ⁇ 63, k ⁇ K im denotes that k is respectively the sequence number of the subcarrier occupied by the station in the ith OFDM symbol, mean ⁇ denotes averaging, angle() denotes phase, H m,i (k) denotes the i-th channel response information of the station, and H m,M+1 (k) denotes the phase compensation channel response of the station
  • the frequency deviation estimation value of each station for the first OFDM symbol can be obtained according to the formula (3), and the frequency deviation estimation value is determined as the frequency deviation estimation value of the station.
  • the AP after determining the frequency deviation estimation value of each station, the AP separately parses and processes the received data signal of the station according to the frequency deviation estimation value and the channel response information of each station, thereby obtaining the parsed data. Data signal.
  • the size of the sequence numbers of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not be taken to the embodiments of the present invention.
  • the implementation process constitutes any limitation.
  • the method for processing a signal in a wireless local area network determines a frequency offset estimation value of the station by determining channel response information of a channel used by the station to transmit the data signal, according to the channel response information and the frequency deviation estimation value, Therefore, the received data signal is parsed, the influence of the frequency deviation between the multiple stations can be avoided, the parsed data signal is more accurate, the error rate of the data signal parsing is reduced, and the receiving performance of the system is enhanced.
  • FIG. 8 shows a schematic flow diagram of a station 300 in a wireless local area network in accordance with an embodiment of the present invention.
  • the site 300 includes:
  • the generating module 310 is configured to generate M OFDM symbols for transmitting a pilot signal, and phase compensated OFDM symbols for transmitting a phase compensated pilot signal, where M is the number of stations of the group where the station is located, and the phase compensation
  • the phase compensated pilot signal in the OFDM symbol satisfies the formula (1), wherein p m (k) represents the phase compensated pilot signal of the station on the kth subcarrier, p 0 is a constant, and m represents the site a sequence number, k represents a sequence number of the subcarrier of the phase compensated OFDM symbol, and ⁇ m represents a phase offset coefficient of the station;
  • the sending module 320 is configured to send the M OFDM symbols including the pilot signal to the AP, and include the phase compensated OFDM symbol of the phase compensated pilot signal, so that the AP determines the frequency offset estimation value.
  • the station in the WLAN of the embodiment of the present invention sends an OFDM symbol including a pilot signal to the AP, and the AP determines the frequency offset estimation value of the station by determining the channel response information of the channel through which the pilot signal is transmitted by the station. According to the channel response information and the frequency deviation estimation value, the AP parses the received data signal to avoid the influence of the frequency deviation between the multiple stations, so that the parsed data signal is more accurate, and the error of the data signal analysis is reduced. The rate, which in turn enhances the reception performance of the system.
  • the station generating module 310 generates M OFDM symbols for transmitting pilot signals, and phase compensated OFDM symbols for transmitting phase compensated pilot signals.
  • M OFDM symbols and phase compensated OFDM symbols may be multiplexed by subcarrier interleaving.
  • the number of subcarriers in the OFDM symbol, m, k, and N take an integer
  • k 0 is the starting position of the subcarrier
  • mod(a, b) represents the a/b remainder.
  • the station may carry the pilot signal transmitted by the station on the kth subcarrier in the phase compensated OFDM symbol, where k 0 ⁇ k ⁇ N-1.
  • Equation (1) where p m (k) represents the pilot signal of the station on the kth subcarrier, p 0 is a constant, k represents the sequence number of the subcarrier of the OFDM symbol, and ⁇ m represents the phase of the station Offset factor.
  • the M OFDM symbols and the phase compensated OFDM symbols generated by the generating module 310 may also be multiplexed by means of block interleaving. Specifically, for the M OFDM symbols transmitted by the mth station, the pilot signal that the station needs to transmit is carried on the kth subcarrier in the i th OFDM symbol, where the kth subcarrier is in the first group of subcarriers.
  • the number of subcarriers in the symbol, l, L, m, k, and N are integers, k 0 is the starting position of the subcarrier, and mod(a, b) is the remainder of a/b.
  • the station may carry the pilot signal transmitted by the station on the kth subcarrier in the phase compensated OFDM symbol, where k 0 ⁇ k ⁇ N-1.
  • the pilot signal of the station may be carried on the kth subcarrier in the phase compensated OFDM symbol, where the kth subcarrier is in the first group of subcarriers, and the first group of subcarriers includes L subcarriers.
  • k mod(k 0 +(m-1)L+lML+(z-1)L+x,N),1 ⁇ z ⁇ M,z takes an integer, 0 ⁇ x ⁇ L, x takes an integer, k 0
  • the starting position of the subcarrier, 0 ⁇ l ⁇ N/(L*M), L is an integer greater than or equal to 2, and the pilot signal in the M OFDM symbols used by the station for transmitting the pilot signal satisfies the formula (1), where p m (k) represents the pilot signal of the station on the kth subcarrier, p 0 is a constant, k represents the sequence number of the subcarrier of the OFDM symbol, and ⁇ m represents the phase offset of the station Shift coefficient.
  • the phase compensated OFDM symbols generated by the generating module 310 of the station may be multiplexed by means of CSD, that is, the phase compensated pilot signals transmitted by different stations and the preset phase compensated pilot signals are in different subcarriers.
  • the sending module of the station sends, to the AP, the M OFDM symbols including the pilot signal and the phase compensated OFDM symbol including the phase compensated pilot signal generated by the generating module 310, so as to facilitate the AP according to the pilot signal and
  • the phase compensated pilot signal determines channel corresponding information and determines a frequency offset estimate based on the channel corresponding information.
  • site 300 may correspond to 100 performing the method in the embodiment of the present invention, and the above and other operations and/or functions of the respective modules in the site 300 are respectively implemented to implement the respective methods in FIG. The corresponding process, for the sake of brevity, will not be described here.
  • the station in the WLAN of the embodiment of the present invention sends an OFDM symbol including a pilot signal to the AP, and the AP determines the channel response signal of the channel through which the pilot transmits the pilot signal.
  • the information is used to determine the frequency deviation estimation value of the station.
  • the AP parses the received data signal to avoid the influence of the frequency deviation between the multiple stations, so that the parsed data signal is more Accurate, reducing the bit error rate of data signal parsing, thereby enhancing the receiving performance of the system.
  • an access point 400 in a wireless local area network includes:
  • the first determining module 410 is configured to determine channel response information of a channel through which the station sends the data signal;
  • a second determining module 420 configured to determine, according to the channel response information, an estimated frequency deviation of the station
  • the receiving module 430 is configured to receive the data signal sent by the station on the channel;
  • the processing module 440 is configured to parse the data signal according to the channel response information and the frequency offset estimation value.
  • the access point in the WLAN of the embodiment of the present invention determines the frequency offset estimation value of the station by determining the channel response information of the channel used by the station to transmit the data signal, according to the channel response information and the frequency offset estimation value, Therefore, the received data signal is parsed, the influence of the frequency deviation between the multiple stations can be avoided, the parsed data signal is more accurate, the error rate of the data signal parsing is reduced, and the receiving performance of the system is enhanced.
  • the first determining module 410 of the AP determines channel response information of a channel used by the station to transmit the data signal. Specifically, the first determining module 410 of the AP determines an OFDM symbol through which the station transmits the pilot signal, obtains a pilot signal according to the OFDM symbol, and determines channel response information of the station according to the pilot signal.
  • the station transmits M OFDM symbols and one phase compensated OFDM symbol, where M is the number of stations in which the station is located.
  • the M OFDM symbols may be multiplexed by means of subcarrier interleaving, that is, for the M OFDM symbols transmitted by the mth station, the station needs to be sent on the kth subcarrier in the ith OFDM symbol.
  • the first determining module 410 of the AP determines a pilot signal carried on M OFDM symbols transmitted by the mth station.
  • the pilot signal on the kth subcarrier in the ith OFDM symbol can be directly received as the pilot signal of the mth station on the kth subcarrier.
  • the ith OFDM symbol may be separated to obtain a pilot signal of the mth station on the kth subcarrier.
  • the AP simultaneously receives the pilot signals sent by the multiple stations, performs an inverse Fourier transform IDFT on the pilot signals, performs filtering processing on the transformed pilot signals, and finally performs Fourier transform on the pilot signals.
  • the DFT is transformed to obtain the pilot signals of different stations, and the pilot signals of different stations are separated from each other, and the pilot signals of the m stations are obtained by separating the pilot signals of the respective stations to obtain the pilot signals of the mth station.
  • the first determining module 410 of the AP determines the channel response information of the station according to the comparison between the preset pilot signal and the received pilot signal.
  • the mth station may be determined by formula (2) according to the received pilot signal of the mth station on the ith OFDM symbol and the pilot signal preset by the station on the OFDM symbol.
  • the i-th channel response information where r m (k) represents the pilot signal transmitted by the received mth station on the k-th subcarrier on the ith OFDM symbol, and P m (k) represents the mth
  • the station presets a pilot signal on the kth subcarrier on the ith OFDM symbol, and H m (k) represents the i th channel response information of the mth station on the kth subcarrier.
  • the preset phase compensation pilot signals of different stations satisfy the formula (1) on different subcarriers, where P m (k) is the preset phase of the mth station on the kth subcarrier.
  • P m (k) is the preset phase of the mth station on the kth subcarrier.
  • the AP determines the frequency deviation estimation value of the station by using the second determining module 420 according to the channel response information determined by the first determining module 410. Specifically, the AP may first determine, by the first determining module 410, the phase compensation channel response information of the channel used by the station to transmit the phase compensation pilot signal, and the channel response information and phase compensation determined according to the first determining module 410. The channel response information is determined by the second determining module 420 for the frequency offset estimate for the station.
  • the station transmits M OFDM symbols and one phase compensated OFDM symbol, where M is the number of stations in which the station is located.
  • M the number of stations in which the station is located.
  • the pilot signal that the station needs to transmit is carried on the kth subcarrier in the ith OFDM symbol.
  • the pilot signal transmitted by the station may be carried on each subcarrier in the phase compensated OFDM symbol, or may be carried on the kth subcarrier in the phase compensated OFDM symbol.
  • the pilot signal of the station may be carried on each subcarrier in the phase compensated OFDM symbol, or may be carried on the kth subcarrier in the phase compensated OFDM symbol.
  • the site of the pilot signal multiplexed subcarrier interleaved manner or in a block interleaving manner when multiplexing sites on the subsequent phase compensation OFDM symbol of k 0 th subcarrier of each subcarrier carries the The pilot signal of the station
  • the kth subcarrier carrying the pilot signal satisfies k 0 ⁇ k ⁇ N-1.
  • the pilot signal in the M OFDM symbols used by the station to transmit the pilot signal may satisfy the formula (1), where p m (k) represents the pilot signal of the station on the kth subcarrier, p 0 is a constant, k represents the sequence number of the subcarrier of the OFDM symbol, and ⁇ m represents the phase offset coefficient of the station.
  • the phase compensated OFDM symbols are multiplexed by cyclic shift (CSD), and the preset phase compensated pilot signals of different stations satisfy the following formula (1) on different subcarriers, where p m (k) is the phase compensated pilot signal of the mth station on the kth subcarrier, p 0 is a constant, indicating a basic pilot signal of amplitude 1 and CP is the guard interval length of the phase compensated OFDM symbol, j For imaginary units, The preset phase compensated pilot signal for each station also satisfies equation (1).
  • the first determining module 410 of the AP may also determine a phase compensated pilot signal of the phase compensated OFDM symbol. Specifically, when each subcarrier in the phase compensated OFDM symbol carries a phase compensated pilot signal, the phase compensated pilot signal received by the AP on each subcarrier is a phase compensated pilot signal belonging to multiple stations. Superimposed, the pilot signals of each station on each subcarrier can be determined separately by separation. When the station only carries the phase-compensated pilot information on the k-th subcarrier in the phase-compensated OFDM symbol, after the AP receives the CSD multiplexed mode, the phase pilot symbols of different stations are carried on each sub-carrier, and the same can be adopted. The separation method separates the pilot signals of each station on each subcarrier to obtain a more accurate phase compensation pilot signal.
  • the separation of the pilot signals can be performed by the following method. Performing an inverse Fourier transform IDFT on the phase compensated pilot signal received by the AP to obtain a first pilot signal, and then filtering the first pilot signal to obtain a second pilot signal, and finally the second pilot signal The signal is subjected to Fourier transform DFT to obtain a third pilot signal including phase compensated pilot signals of different stations, and phase compensated pilot signals of different stations are separated from each other, and phase compensation pilot signals of respective stations are separated to obtain A phase compensated pilot signal on the kth subcarrier of the mth station in the phase compensated OFDM symbol.
  • phase compensation channel response information of the mth station may be determined by equation (2), where r m (k) represents the received phase compensated pilot signal of the mth station on the phase compensated OFDM symbol, P m (k) indicates that the station presets a phase compensated pilot signal on the phase compensated OFDM symbol, and H m (k) represents phase compensation channel response information of the mth station.
  • the AP determines the frequency offset estimation value of the station by the second determining module 420 according to the ith channel response information and the phase compensation channel response information of the station determined by the first determining module 410.
  • the frequency deviation estimation value of the station may be determined by determining the i-th channel response information and the phase compensation channel response information of the station, and the site may be determined by the M channel response information and the phase compensation channel response information of the station. M frequency deviation estimates, The average of the M frequency offset estimates is determined as the frequency offset estimate for the station.
  • the i-th frequency offset estimation value ⁇ F m,i of the mth station may be determined by formula (3), where m represents the sequence number of the station, 1 ⁇ m ⁇ M, and CP represents the i-th OFDM symbol
  • the guard interval length where N is the number of subcarriers in the i-th OFDM symbol, and k is the sequence number of the subcarrier occupied by the mth station in the i-th OFDM symbol, k 0 ⁇ k ⁇ N-1,k ⁇ K im denotes that k respectively takes the sequence number of the subcarrier occupied by the station in the i-th OFDM symbol, mean ⁇ denotes an average, angle() denotes a phase, and H m,i (k) denotes the site
  • H i-th channel response information, H m, M+1 (k) represents the phase compensation channel response information of the station, Represents the conjugate of H m,M+1 (k).
  • the AP receives the data signal sent by the station through the channel through the receiving module 430.
  • the processing module 440 of the AP performs parsing processing on the data signal received by the receiving module 230 according to the channel response information determined by the first determining module 410 and the frequency offset estimation value determined by the second determining module 420.
  • the AP may parse the data signal by using the processing module 440 according to the formula (3), where r is the data signal sent by the AP received by the AP, h is the channel response information of the station, and s is the data signal.
  • the result of the analysis the result can be determined as the original data signal sent by the station, ⁇ is the estimated frequency deviation of the station, and j is an imaginary unit. n is noise.
  • the AP can parse the data signal sent more accurately and closer to the station.
  • the AP 400 may correspond to 200 performing the method in the embodiment of the present invention, and the above and other operations and/or functions of the respective modules in the AP 400 are respectively implemented to implement the respective methods in FIG. The process, for the sake of brevity, will not be described here.
  • the access point in the WLAN of the embodiment of the present invention determines the frequency offset estimation value of the station by determining the channel response information of the channel used by the station to transmit the data signal, according to the channel response information and the frequency offset estimation value, Therefore, the received data signal is parsed, the influence of the frequency deviation between the multiple stations can be avoided, the parsed data signal is more accurate, the error rate of the data signal parsing is reduced, and the receiving performance of the system is enhanced.
  • an embodiment of the present invention further provides a station 500 in a wireless local area network, where the station 500 includes a processor 510, a memory 520, a transmitter 530, and a bus system 540.
  • the processor 510, the memory 520 and the receiver 530 are connected by a bus system 540 for storing instructions for executing the instructions stored by the memory 520 to control the receiver 330 to receive signals.
  • the processor 510 is configured to generate M OFDM symbols for transmitting pilot signals, and phase compensated OFDM symbols for transmitting phase compensated pilot signals, where M is the number of stations of the group where the station is located, where The phase compensated pilot signal in the phase compensated OFDM symbol satisfies the following formula (1), where p m (k) represents the phase compensated pilot signal of the station on the kth subcarrier, p 0 is a constant, k Representing the sequence number of the subcarrier of the phase compensated OFDM symbol, ⁇ m represents the phase offset coefficient of the station; the transmitter 530 is configured to send the M OFDM symbols including the pilot signal to the AP, and includes the phase compensation guide This phase of the frequency signal compensates for the OFDM symbol so that the AP determines the frequency offset estimate.
  • p m (k) represents the phase compensated pilot signal of the station on the kth subcarrier
  • p 0 is a constant
  • the station in the WLAN of the embodiment of the present invention sends an OFDM symbol including a pilot signal to the AP, and the AP determines the frequency offset estimation value of the station by determining the channel response information of the channel through which the pilot signal is transmitted by the station. According to the channel response information and the frequency deviation estimation value, the AP parses the received data signal to avoid the influence of the frequency deviation between the multiple stations, so that the parsed data signal is more accurate, and the error of the data signal analysis is reduced. The rate, which in turn enhances the reception performance of the system.
  • the processor 510 may be a central processing unit (“CPU"), and the processor 510 may also be other general-purpose processors, digital signal processors (DSPs). , an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, and the like.
  • the general purpose processor may be a microprocessor or the processor or any conventional processor or the like.
  • the memory 520 can include read only memory and random access memory and provides instructions and data to the processor 510. A portion of the memory 520 may also include a non-volatile random access memory. For example, the memory 520 can also store information of the device type.
  • the bus system 540 may include a power bus, a control bus, a status signal bus, and the like in addition to the data bus. However, for clarity of description, various buses are labeled as bus system 540 in the figure.
  • each step of the above method may be integrated by hardware in the processor 510.
  • the logic circuit or the instruction in the form of software is completed.
  • the steps of the method disclosed in the embodiments of the present invention may be directly implemented as a hardware processor, or may be performed by a combination of hardware and software modules in the processor.
  • the software module can be located in a conventional storage medium such as random access memory, flash memory, read only memory, programmable read only memory or electrically erasable programmable memory, registers, and the like.
  • the storage medium is located in the memory 520, and the processor 510 reads the information in the memory 520 and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.
  • the processor 510 is further configured to determine the M OFDM symbols, where a pilot signal of the station is carried on the kth subcarrier in the ith OFDM symbol,
  • m represents the serial number of the station, 1 ⁇ m ⁇ M, k 0 ⁇ k ⁇ N-1,
  • N represents the number of subcarriers in the mth OFDM symbol, l, m, k, and N take integers, k 0 is the starting position of the subcarrier, and mod(a, b) represents a /b taking a remainder; determining the phase compensate
  • the site 5500 may correspond to the site 300 in the embodiment of the present invention, and may correspond to the corresponding body in the method 100 according to the embodiment of the present invention, and the above-described modules in the site 500 are And other operations and/or functions, respectively, in order to implement the corresponding processes of the various methods in FIG. 2, for brevity, no further details are provided herein.
  • the station in the WLAN of the embodiment of the present invention sends an OFDM symbol including a pilot signal to the AP, and the AP determines the frequency offset estimation value of the station by determining the channel response information of the channel through which the pilot signal is transmitted by the station. According to the channel response information and the frequency deviation estimation value, the AP parses the received data signal to avoid the influence of the frequency deviation between the multiple stations, so that the parsed data signal is more accurate, and the error of the data signal analysis is reduced. The rate, which in turn enhances the reception performance of the system.
  • an embodiment of the present invention further provides an access point 600 in a wireless local area network, where the access point 600 includes a processor 610, a memory 620, a receiver 630, and a bus system 640.
  • the processor 610, the memory 620 and the receiver 630 are connected by a bus system 640 for storing instructions for executing instructions stored in the memory 620 to control the receiver 630 to receive signals.
  • the processor 610 is configured to determine channel response information of a channel through which the station transmits the data signal, determine a frequency offset estimation value of the station according to the channel response information, and receive, by the receiver 630, the station to send on the channel.
  • the data signal is further analyzed by the processor 610 based on the channel response information and the frequency offset estimate.
  • the access point in the WLAN of the embodiment of the present invention determines the frequency offset estimation value of the station by determining the channel response information of the channel used by the station to transmit the data signal, according to the channel response information and the frequency offset estimation value, Therefore, the received data signal is parsed, the influence of the frequency deviation between the multiple stations can be avoided, the parsed data signal is more accurate, the error rate of the data signal parsing is reduced, and the receiving performance of the system is enhanced.
  • the processor 610 may be a central processing unit ("CPU"), and the processor 610 may also be other general-purpose processors, digital signal processors (DSPs). , an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, and the like.
  • the general purpose processor may be a microprocessor or the processor or any conventional processor or the like.
  • the memory 620 can include read only memory and random access memory and provides instructions and data to the processor 610. A portion of the memory 620 can also include a non-volatile random access memory. For example, the memory 620 can also store information of the device type.
  • the bus system 640 may include a power bus, a control bus, a status signal bus, and the like in addition to the data bus. However, for clarity of description, various buses are labeled as bus system 640 in the figure.
  • each step of the foregoing method may be completed by an integrated logic circuit of hardware in the processor 610 or an instruction in a form of software.
  • the steps of the method disclosed in the embodiments of the present invention may be directly implemented as a hardware processor, or may be performed by a combination of hardware and software modules in the processor.
  • the software module can be located in a conventional storage medium such as random access memory, flash memory, read only memory, programmable read only memory or electrically erasable programmable memory, registers, and the like.
  • the storage medium is located in the memory 620, and the processor 610 reads the information in the memory 620, and combines the information
  • the hardware completes the steps of the above method. To avoid repetition, it will not be described in detail here.
  • the processor 610 is further configured to determine phase compensation channel response information of a channel through which the station transmits a phase compensation pilot signal, and determine, according to the channel response information and the phase compensation channel response information, The frequency deviation estimate for the site.
  • the processor 610 is further configured to determine M OFDM symbols used by the station to transmit pilot signals, and phase compensated OFDM symbols used to transmit phase compensated pilot signals, where M is a number of stations in which the station is located; determining, according to the i-th OFDM symbol in the M OFDM symbols, channel response information of a channel through which the station transmits the pilot signal in the i-th OFDM symbol as the i-th Channel response information, i takes a positive integer, 1 ⁇ i ⁇ M; according to the phase compensated OFDM symbol, determining the phase compensation channel response information of the channel through which the station transmits the phase compensated pilot signal in the phase compensated OFDM symbol And determining, according to the ith channel response information of the station and the phase compensation channel response information, the frequency offset estimation value of the station.
  • the processor 610 is further configured to determine, according to the M channel response information of the site and the phase compensation channel response information, the M frequency offset estimation values of the site; and determine the M of the site.
  • the average of the frequency deviation estimates is the frequency deviation estimate for the station.
  • the processor 610 is further configured to determine the M OFDM symbols, where a pilot signal of the station is carried on a kth subcarrier in the ith OFDM symbol.
  • k mod(k 0 + m-1 + xM + i-1, N), 0 ⁇ x ⁇ N / M
  • x is an integer
  • m represents the serial number of the station, 1 ⁇ m ⁇ M, k 0 ⁇ k ⁇ N-1
  • N represents the number of subcarriers in the mth OFDM symbol
  • m, k and N are integers
  • k 0 is the starting position of the subcarrier
  • mod(a, b) represents a/ Taking a remainder; determining the phase compensated OFDM symbol, wherein the phase compensated pilot signal of the station is carried on the kth subcarrier in the phase compensated OFDM symbol, where k 0 ⁇ k ⁇ N-1, k 0 is a sub The starting position of the carrier.
  • the processor 610 is further configured to determine the M OFDM symbols, where a pilot signal of the station is carried on a kth subcarrier in the ith OFDM symbol.
  • k mod(k 0 + m-1 + xM + i-1, N), 0 ⁇ x ⁇ N / M
  • x is an integer
  • m represents the serial number of the station
  • N represents the number of subcarriers in the mth OFDM symbol
  • m, k and N are integers
  • k 0 is the starting position of the subcarrier
  • the processor 610 is further configured to determine the M OFDM symbols, where a pilot signal of the station is carried on a kth subcarrier in the ith OFDM symbol.
  • the kth subcarrier is in the first group of subcarriers
  • L is an integer greater than or equal to 2
  • m represents the serial number of the station, 1 ⁇ m ⁇ M, k 0 ⁇ k ⁇ N-1
  • N represents the number of subcarriers in the mth OFDM symbol
  • l, m, k, and N take integers
  • k 0 is the starting position of the subcarrier
  • mod(a, b) represents a/b taking a remainder
  • the processor 610 is further configured to determine the M OFDM symbols, where a pilot signal of the station is carried on a kth subcarrier in the ith OFDM symbol.
  • the kth subcarrier is in the first group of subcarriers
  • L is an integer greater than or equal to 2
  • m represents the serial number of the station, 1 ⁇ m ⁇ M, k 0 ⁇ k ⁇ N-1
  • N represents the number of subcarriers in the mth OFDM symbol
  • l, m, k, and N take integers
  • k 0 is the starting position of the subcarrier
  • mod(a, b) represents a/b taking a remainder
  • the processor 610 is further configured to determine the phase compensated OFDM symbol, where the phase compensated pilot signal in the phase compensated OFDM symbol of the station satisfies the formula (1), where p m ( k) represents the phase compensated pilot signal of the station on the kth subcarrier, p 0 is a constant, k represents the sequence number of the subcarrier of the phase compensated OFDM symbol, and ⁇ m represents the phase offset coefficient of the station.
  • the processor 610 is further configured to determine the M OFDM symbols, where the pilot signal in the M OFDM symbols satisfies the formula (1), where p m (k) represents the site The pilot signal on the kth subcarrier, p 0 is a constant, k represents the sequence number of the subcarrier of the OFDM symbol, and ⁇ m represents the phase offset coefficient of the station.
  • the processor 610 is further configured to determine, according to formula (3), the frequency deviation estimation value of the station, where ⁇ F m,i represents an ith frequency offset estimation value of the station, where Indicates the sequence number of the station, 1 ⁇ m ⁇ M, CP indicates the guard interval length of the i-th OFDM symbol, N indicates the number of subcarriers in the i-th OFDM symbol, and k indicates that the station is at the ith OFDM
  • the sequence number of the subcarrier occupied by the symbol, k 0 ⁇ k ⁇ N-1, k ⁇ K im indicates that k respectively takes the sequence number of the subcarrier occupied by the station in the ith OFDM symbol, and mean ⁇ indicates
  • angle() indicates phase
  • H m,i (k) indicates the i-th channel response information of the station
  • H m,M+1 (k) indicates the phase compensation channel response information of the station. Represents the conjugate of H m,M+1 (k).
  • the processor 610 is further configured to determine a received pilot signal in the i-th OFDM symbol of the M OFDM symbols sent by the station; and according to the ith preset pilot signal and The received pilot signal in the ith OFDM symbol determines the ith channel response information of the station; determines the phase compensated pilot signal in the phase compensated OFDM symbol sent by the station; and compensates the pilot according to the preset phase The signal and the phase compensated pilot signal determine the phase compensation channel response information for the station.
  • the processor 610 is further configured to receive a pilot signal in a phase compensated OFDM symbol sent by multiple stations, perform an inverse Fourier transform IDFT on the pilot signal, and determine a first pilot. Transmitting the first pilot signal to determine a second pilot signal; performing a Fourier transform DFT on the second pilot signal to determine a third pilot signal; determining, according to the third pilot signal, The phase transmitted by the station compensates for the phase compensated pilot signal in the OFDM symbol.
  • an access point 600 in accordance with an embodiment of the present invention may correspond to an access point 400 in an embodiment of the present invention and may correspond to performing a corresponding body in the method 200 in accordance with an embodiment of the present invention, and the access point 600
  • the above-mentioned and other operations and/or functions of the respective modules in order to implement the corresponding processes of the respective methods in FIG. 3 are omitted for brevity.
  • the access point in the WLAN of the embodiment of the present invention determines the frequency deviation estimation value of the station by determining the channel response information of the channel used by the station to transmit the data signal, according to the The channel response information and the frequency deviation estimation value, thereby analyzing the received data signal, can avoid the influence of the frequency deviation between the multiple stations, so that the parsed data signal is more accurate, and the error rate of the data signal analysis is reduced, thereby further Enhanced system reception performance.
  • the disclosed systems, devices, and methods may be implemented in other manners.
  • the device embodiments described above are merely illustrative.
  • the division of the unit is only a logical function division.
  • there may be another division manner for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed.
  • the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.
  • each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.
  • the functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product.
  • the technical solution of the present invention which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium, including
  • the instructions are used to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention.
  • the storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, which can store program codes.

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Abstract

本发明实施例涉及无线局域网中处理信号的方法、站点和接入点。该方法包括：确定站点发送数据信号所经过的信道的信道响应信息（S210）；根据该信道响应信息，确定该站点的频率偏差估计值（S220）；接收该站点在该信道发送的该数据信号（S230）；根据该信道响应信息和该频率偏差估计值，解析该数据信号（S240）。本发明实施例的处理信号的方法、站点和接入点，根据该信道响应信息和频率偏差估计值，解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。

Description

无线局域网中处理信号的方法、站点和接入点 技术领域
本发明实施例涉及通信领域，并且更具体地，涉及一种无线局域网中处理信号的方法、站点和接入点。
背景技术
无线局域网(例如WiFi或WLAN)系统也就是电气与电子工程师协会(Institute of Electrical and Electronic Engineers，IEEE)的802.11系统，历经802.11a，802.11b，802.11d，802.11n和802.11ac等各个版本，技术发展越来越成熟，提供的系统传输速度也越来越大。为了进一步提高无线局域网的吞吐量，WiFi系统未来将会考虑引入上行多用户多入多出(Multi User Multiple Input Multiple Output，简称“MU-MIMO”)技术，上行MU-MIMO技术的引入也是为了解决链路两侧的天线数目不对称的问题。在上行MU-MIMO技术中，多个站点可以向接入点(Access Point，AP)同时传输数据，此时，同时传输数据的各个用户在时间上与频率需要保证同步。
在单发单收时，虽然接入点AP利用段训练字段(Short Training Field，简称“STF”)可以实现AP和发射机之间的频率同步，但由于噪声和干扰的影响，不可能实现完全的频率同步，会以残留频率偏差存在。残留频率偏差的存在会导致接收信号产生相位偏转。此时，存在频率偏差时的接收信号可以表示如下：
r＝hejφs+n
其中：r为接收信号，h为利用长训练字段(Long Training Field，简称“LTF”)获得的信道估计结果，j为虚数单位
Figure PCTCN2014091160-appb-000001
Φ是由于残留频偏和相位噪声导致的频率偏差，n为噪声。在h已知的条件下，信道均衡虽然可以消除h的影响，但解析得到的站点的发送信号中依然存在频率偏差Φ的影响。
这种情况在上行MU-MIMO时尤为严重。由于多个上行用户独立发送信号，彼此之间存在频率偏差，接收时AP依靠STF无法做到和所有的用户同步。以两个数据流为例，此时的接收信号可以表示为：
Figure PCTCN2014091160-appb-000002
因此，在上行MU-MIMO时，不同的上行发射机和AP之间存在不同的频率偏差，将会导致接收信号的误码率增加甚至无法解调，从而严重影响系统接收性能，上行的用户越多，该问题就越严重。
发明内容
本发明提供了一种无线局域网中处理信号的方法、站点和接入点，能够减少数据信号解析的误码率，进而增强系统的接收性能。
第一方面，提供了一种无线局域网中处理信号的方法，该方法包括：生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，该M为站点所在分组的站点的个数，该相位补偿OFDM符号中的该相位补偿导频信号满足下面的公式(1)：
Figure PCTCN2014091160-appb-000003
其中，pm(k)表示该站点在第k个子载波上的该相位补偿导频信号，p0为常数，k表示该相位补偿OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；向接入点发送包括该导频信号的该M个OFDM符号，和，包括该相位补偿导频信号的该相位补偿OFDM符号，以便于接入点确定频率偏差估计值。
结合第一方面，在第一方面的第一种可能的实现方式中，该生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上均承载该站点的该相位补偿导频信号，其中k0≤k≤N-1，k0为子载波的起始位置。
结合第一方面，在第一方面的第二种可能的实现方式中，该生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：确定该M个OFDM符号，该M个OFDM符号中的该导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该 导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，k0为子载波的起始位置，x取整数，mod(a，b)表示a/b取余数。
结合第一方面，在第一方面的第三种可能的实现方式中，该生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k子载波上均承载该站点的该相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
结合第一方面，在第一方面的第四种可能的实现方式中，该生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：确定该M个OFDM符号，该M个OFDM符号中的该导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a， b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，L为大于或等于2的整数，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，1≤z≤M，z取整数，l取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
第二方面，提供了一种无线局域网中处理信号的方法，该方法包括：确定站点发送数据信号所经过的信道的信道响应信息；根据该信道响应信息，确定该站点的频率偏差估计值；接收该站点在该信道发送的该数据信号；根据该信道响应信息和该频率偏差估计值，解析该数据信号。
结合第二方面，在第二方面的第一种可能的实现方式中，该方法还包括：确定该站点发送相位补偿导频信号所经过的信道的相位补偿信道响应信息；该根据该信道响应信息，确定该站点的频率偏差估计值，包括：根据该信道响应信息和该相位补偿信道响应信息，确定该站点的该频率偏差估计值。
结合第二方面的第一种可能的实现方式，在第二方面的第二种可能的实现方式中，该方法还包括：确定该站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，该M为站点所在分组的站点的个数；该确定站点发送数据信号所经过的信道的信道响应信息，包括：根据该M个OFDM符号中的第i个OFDM符号，将该站点发送该第i个OFDM符号中的导频信号所经过的信道的信道响应信息确定为第i个信道响应信息，i取正整数，1≤i≤M；该确定该站点发送相位补偿导频信号所经过的信道的相位补偿信道响应信息，包括：根据该相位补偿OFDM符号，确定该站点发送该相位补偿OFDM符号中的相位补偿导频信号所经过的信道的该相位补偿信道响应信息；该根据该信道响应信息和该相位补偿信道响应信息，确定该站点的该频率偏差估计值，包括：根据该站点的该第i个信道响应信息和该相位补偿信道响应信息，确定该站点的该频率偏差估计值。
结合第二方面的第二种可能的实现方式，在第二方面的第三种可能的实现方式中，该根据该站点的该第i个信道响应信息和该相位补偿信道响应信息，确定该站点的该频率偏差估计值，包括：根据该站点的M个信道响应信息和该相位补偿信道响应信息，确定该站点的M个频率偏差估计值；确 定该站点的该M个频率偏差估计值的平均值为该站点的该频率偏差估计值。
结合第二方面的第二种或第三种可能的实现方式，在第二方面的第四种可能的实现方式中，该确定该站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k子载波上均承载该站点的该相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
结合第二方面的第二种或第三种可能的实现方式，在第二方面的第五种可能的实现方式中，该确定该站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，x取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
结合第二方面的第二种或第三种可能的实现方式，在第二方面的第六种可能的实现方式中，该确定该站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a， b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k子载波上均承载该站点的该相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
结合第二方面的第二种或第三种可能的实现方式，在第二方面的第七种可能的实现方式中，该确定该站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，L为大于或等于2的整数，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)，1≤z≤M，z取整数，0≤x<L，x取整数，0≤l≤N/(L*M)，l取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
结合第二方面的第四种至第七种可能的实现方式中的任一种可能的实现方式，在第二方面的第八种可能的实现方式中，该确定该站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：确定该相位补偿OFDM符号，该站点的该相位补偿OFDM符号中的该相位补偿导频信号满足公式(1)：
Figure PCTCN2014091160-appb-000004
其中，pm(k)表示该站点在第k个子载波上的该相位补偿导频信号，p0为常数，k表示该相位补偿OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
结合第二方面的第五种或第七种可能的实现方式，在第二方面的第九种可能的实现方式中，该确定该站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：确定该M个OFDM符号，该M个OFDM符号中的该导频信号满足公式(1)，其中， pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
结合第二方面的第一种至第九种可能的实现方式中的任一种可能的实现方式，在第二方面的第十种可能的实现方式中，该根据该信道响应信息和该相位补偿信道响应信息，确定该站点的该频率偏差估计值，包括：根据下面的公式(2)确定该站点的该频率偏差估计值：
Figure PCTCN2014091160-appb-000005
其中，δFm,i表示该站点的第i个频率偏差估计值，m表示该站点的序号，1≤m≤M，CP表示该第i个OFDM符号的保护间隔长度，N表示该第i个OFDM符号中的子载波的个数，k表示该站点在第i个OFDM符号中占用的该子载波的序号，k0≤k≤N-1，k∈Kim表示k分别取该站点在该第i个OFDM符号中占用的该子载波的序号，mean{}表示求平均值，angle()表示求相位，Hm,i(k)表示该站点的第i个信道响应信息，Hm,M+1(k)表示该站点的该相位补偿信道响应信息，
Figure PCTCN2014091160-appb-000006
表示Hm,M+1(k)的共轭。
结合第二方面的第二种至第十种可能的实现方式中的任一种可能的实现方式，在第二方面的第十一种可能的实现方式中，该根据该M个OFDM符号中的第i个OFDM符号，将该站点发送该第i个OFDM符号中的导频信号所经过的信道的信道响应信息确定为第i个信道响应信息，包括：确定该站点发送的该M个OFDM符号中的第i个OFDM符号中的接收导频信号；根据第i个预设导频信号和该第i个OFDM符号中的接收导频信号确定该站点的该第i个信道响应信息；该根据该相位补偿OFDM符号，确定该站点发送该相位补偿OFDM符号中的相位补偿导频信号所经过的信道的该相位补偿信道响应信息，包括：确定该站点发送的该相位补偿OFDM符号中的该相位补偿导频信号；根据预设相位补偿导频信号和该相位补偿导频信号，确定该站点的该相位补偿信道响应信息。
结合第二方面的第十一种可能的实现方式，在第二方面的第十二种可能的实现方式中，该确定该站点发送的该相位补偿OFDM符号中的该相位补偿导频信号，包括：接收多个站点发送的相位补偿OFDM符号中的导频信号；将该导频信号进行逆傅里叶变换IDFT，确定第一导频信号；将该第一导频信号进行滤波处理，确定第二导频信号；将该第二导频信号进行傅里叶 变换DFT，确定第三导频信号；根据该第三导频信号，确定该站点发送的该相位补偿OFDM符号中的该相位补偿导频信号。
第三方面，提供了一种无线局域网中的站点，该站点包括：生成模块，用于生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，该M为站点所在分组的站点的个数，该相位补偿OFDM符号中的该相位补偿导频信号满足下面的公式(1)：
Figure PCTCN2014091160-appb-000007
其中，pm(k)表示该站点在第k个子载波上的该相位补偿导频信号，p0为常数，k表示该相位补偿OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；发送模块，用于向接入点发送包括该导频信号的该M个OFDM符号，和，包括该相位补偿导频信号的该相位补偿OFDM符号，以便于接入点确定频率偏差估计值。
结合第三方面，在第三方面的第一种可能的实现方式中，该生成模块具体用于：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k子载波上均承载该站点的该相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
结合第三方面，在第三方面的第二种可能的实现方式中，该生成模块具体用于：确定该M个OFDM符号，该M个OFDM符号中的该导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中， k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，x取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
结合第三方面，在第三方面的第三种可能的实现方式中，该生成模块具体用于：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k子载波上均承载该站点的该相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
结合第三方面，在第三方面的第四种可能的实现方式中，该生成模块具体用于：确定该M个OFDM符号，该M个OFDM符号中的该导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，L为大于或等于2的整数，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x<L，x取整数，0≤l≤N/(L*M)，l取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
第四方面，提供了一种无线局域网中的接入点，该接入点包括：第一确定模块，用于确定站点发送数据信号所经过的信道的信道响应信息；第二确定模块，用于根据该信道响应信息，确定该站点的频率偏差估计值；接收模 块，用于接收该站点在该信道发送的该数据信号；处理模块，用于根据该信道响应信息和该频率偏差估计值，解析该数据信号。
结合第四方面，在第四方面的第一种可能的实现方式中，该第一确定模块还用于：确定该站点发送相位补偿导频信号所经过的信道的相位补偿信道响应信息；该第二确定模块具体用于：根据该信道响应信息和该相位补偿信道响应信息，确定该站点的该频率偏差估计值。
结合第四方面的第一种可能的实现方式，在第四方面的第二种可能的实现方式中，该第一确定模块具体用于：确定该站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，该M为站点所在分组的站点的个数；根据该M个OFDM符号中的第i个OFDM符号，将该站点发送该第i个OFDM符号中的导频信号所经过的信道的信道响应信息确定为第i个信道响应信息，i取正整数，1≤i≤M；根据该相位补偿OFDM符号，确定该站点发送该相位补偿OFDM符号中的相位补偿导频信号所经过的信道的该相位补偿信道响应信息；该第二确定模块具体用于：根据该站点的该第i个信道响应信息和该相位补偿信道响应信息，确定该站点的该频率偏差估计值。
结合第四方面的第二种可能的实现方式，在第四方面的第三种可能的实现方式中，该第二确定模块具体用于：根据该站点的M个信道响应信息和该相位补偿信道响应信息，确定该站点的M个频率偏差估计值；确定该站点的该M个频率偏差估计值的平均值为该站点的该频率偏差估计值。
结合第四方面的第二种或第三种可能的实现方式，在第四方面的第四种可能的实现方式中，该第一确定模块具体用于：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k子载波上均承载该站点的该相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
结合第四方面的第二种或第三种可能的实现方式，在第四方面的第五种可能的实现方式中，该第一确定模块具体用于：确定该M个OFDM符号， 该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，x取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
结合第四方面的第二种或第三种可能的实现方式，在第四方面的第六种可能的实现方式中，该第一确定模块具体用于：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k子载波上均承载该站点的该相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
结合第四方面的第二种或第三种可能的实现方式，在第四方面的第七种可能的实现方式中，该第一确定模块具体用于：确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，L为大于或等于2的整数，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x<L，x取整数， 0≤l≤N/(L*M)，l取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
结合第四方面的第四种至第七种可能的实现方式中的任一种可能的实现方式，在第四方面的第八种可能的实现方式中，该第一确定模块具体用于：确定该相位补偿OFDM符号，该站点的该相位补偿OFDM符号中的该相位补偿导频信号满足公式(1)：
Figure PCTCN2014091160-appb-000008
其中，pm(k)表示该站点在第k个子载波上的该相位补偿导频信号，p0为常数，k表示该相位补偿OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
结合第四方面的第五种或第七种可能的实现方式，在第四方面的第九种可能的实现方式中，该第一确定模块具体用于：确定该M个OFDM符号，该M个OFDM符号中的该导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
结合第四方面的第一种至第九种可能的实现方式中的任一种可能的实现方式，在第四方面的第十种可能的实现方式中，该第二确定模块具体用于：根据下面的公式(2)确定该站点的该频率偏差估计值：
Figure PCTCN2014091160-appb-000009
其中，δFm,i表示该站点的第i个频率偏差估计值，m表示该站点的序号，1≤m≤M，CP表示该第i个OFDM符号的保护间隔长度，N表示该第i个OFDM符号中的子载波的个数，k表示该站点在第i个OFDM符号中占用的该子载波的序号，k0≤k≤N-1，k∈Kim表示k分别取该站点在该第i个OFDM符号中占用的该子载波的序号，mean{}表示求平均值，angle()表示求相位，Hm,i(k)表示该站点的第i个信道响应信息，Hm,M+1(k)表示该站点的该相位补偿信道响应信息，
Figure PCTCN2014091160-appb-000010
表示Hm,M+1(k)的共轭。
结合第四方面的第二种至第十种可能的实现方式中的任一种可能的实现方式，在第四方面的第十一种可能的实现方式中，该第一确定模块具体用于：确定该站点发送的该M个OFDM符号中的第i个OFDM符号中的接收导频信号；根据第i个预设导频信号和该第i个OFDM符号中的接收导频信 号确定该站点的该第i个信道响应信息；确定该站点发送的该相位补偿OFDM符号中的该相位补偿导频信号；根据预设相位补偿导频信号和该相位补偿导频信号，确定该站点的该相位补偿信道响应信息。
结合第四方面的第十一种可能的实现方式，在第四方面的第十二种可能的实现方式中，该第一确定模块具体用于：接收多个站点发送的相位补偿OFDM符号中的导频信号；将该导频信号进行逆傅里叶变换IDFT，确定第一导频信号；将该第一导频信号进行滤波处理，确定第二导频信号；将该第二导频信号进行傅里叶变换DFT，确定第三导频信号；根据该第三导频信号，确定该站点发送的该相位补偿OFDM符号中的该相位补偿导频信号。
基于上述技术方案，本发明实施例的无线局域网中处理信号的方法、站点和接入点，通过确定站点用于发送数据信号的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
附图说明
为了更清楚地说明本发明实施例的技术方案，下面将对本发明实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1a是本发明实施例可应用的无线局域网的部署场景示意图。
图1b是根据本发明实施例的无线局域网中处理信号的方法的示意性流程图。
图2是根据本发明实施例的无线局域网中处理信号的方法的示意性流程图。
图3是根据本发明实施例的无线局域网中处理信号的方法的另一示意性流程图。
图4是根据本发明实施例的OFDM符号排列的示意图。
图5是根据本发明实施例的OFDM符号排列的另一示意图。
图6是根据本发明实施例的OFDM符号排列的再一示意图。
图7是根据本发明实施例的OFDM符号排列的再一示意图。
图8是根据本发明实施例的无线局域网中的站点的示意框图。
图9是根据本发明实施例的无线局域网中的接入点的示意框图。
图10是根据本发明实施例的无线局域网中的站点的另一示意框图。
图11是根据本发明实施例的无线局域网中的接入点的另一示意框图。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本发明的一部分实施例，而不是全部实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动的前提下所获得的所有其他实施例，都应属于本发明保护的范围。
图1a为一个本发明实施方式的WLAN系统的简单示意图。图1a的系统包括一个或者多个接入点AP101和一个或者多个站点STA102，图1a以一个接入点和两个个站点为例。接入点101和站点102之间可以采用MU-MIMO技术进行无线通信。
接入点(AP，Access Point)，也可称之为无线访问接入点或桥接器或热点等，其可以接入服务器或通信网络。
站点(STA，Station)，还可以称为用户设备，可以是无线传感器、无线通信终端或移动终端，如支持WiFi通讯功能的移动电话(或称为“蜂窝”电话)和具有无线通信功能的计算机。例如，可以是支持WiFi通讯功能的便携式、袖珍式、手持式、计算机内置的，可穿戴的，或者，车载的无线通信装置，它们与无线接入网交换语音、数据等通信数据。本领域技术人员知道，一些通信设备可能同时具有上述接入点或者站点的功能，在此不予限制。
图1b示出了根据本发明实施例的无线局域网中处理信号的方法的示意性流程图。如图1所示，在WLAN系统中，站点将包括数据信号的帧结构发送至AP，AP接收后，利用本地AP的STF和接收的数据信号进行同步，从而实现符号同步和频率同步。由于WiFi 802.11b以上的版本均以正交频分复用(Orthogonal Frequency Division Multiplexing，OFDM)符号作为调制形式，因此AP进行符号同步后需要移除保护间隔；然后将时域信号转换为频域信号。AP利用接收的长训练字段(Long Training Field，简称“LTF”)进行信道估计，以获得信道信息。AP在对数据进行处理之前，需要利用LTF获得 的信道估计的信息对接收到的频域数据进行均衡以消除信道的影响；由于相位噪声以及残留频偏的影响，信道均衡后的数据依然会受到频率偏差的影响，AP还需要对该频率偏差进行补偿。根据信道估计的结果和频率偏差进行补偿之后，对数据信号进行解码解调等处理以获得数据流。
在单发单收时，存在的频率偏差较小，可以忽略不计，但是在多用户MIMO技术中，频率偏差影响较大，会导致接收信号的误码率增加或者无法解码。因此本发明实施例提供了一种无线局域网中处理信号的方法、站点和接入点，通过计算频率偏差估计值来消除频率偏差的影响。
图2示出了根据本发明实施例的无线局域网中处理信号的方法100的示意性流程图，该方法100可以由站点执行。如图2所示，该方法100包括：
S110，生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，该M为站点所在分组的站点的个数，该相位补偿OFDM符号中的该相位补偿导频信号满足下面的公式(1)：
Figure PCTCN2014091160-appb-000011
其中，pm(k)表示该站点在第k个子载波上的该相位补偿导频信号，p0为常数，k表示该相位补偿OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；
S120，向接入点发送包括该导频信号的该M个OFDM符号，和，包括该相位补偿导频信号的该相位补偿OFDM符号，以便于接入点确定频率偏差估计值。
因此，本发明实施例的无线局域网中处理信号的方法，站点将包括导频信号的OFDM符号发送至AP，AP通过确定站点发送导频信号所经过的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，AP解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
在S110中，站点生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号。可选地，M个OFDM符号，和，相位补偿OFDM符号可以通过子载波交织的方式进行复用。具体地，对于第m个站点发送的M个OFDM符号，在第i个OFDM符号中的第k个子载波上承载该站点需要发送的导频信号，其中， k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。而对于相位补偿OFDM符号，可选地，站点可以在该相位补偿OFDM符号中的第k个子载波上均承载该站点发送的导频信号，其中，k0≤k≤N-1。可选地，也可以在相位补偿OFDM符号中的第k个子载波上承载该站点的导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，x取整数，此时站点用于发送导频信号的M个OFDM符号中的导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
可选地，在本发明实施例中，M个OFDM符号，和，相位补偿OFDM符号还可以通过块交织的方式进行复用。具体地，对于第m个站点发送的M个OFDM符号，在第i个OFDM符号中的第k个子载波上承载该站点需要发送的导频信号，其中，第k个子载波在第l组子载波中，该第l组子载波中包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、L、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。而对于相位补偿OFDM符号，可选地，站点可以在该相位补偿OFDM符号中的第k个子载波上均承载该站点发送的导频信号，k0≤k≤N-1。可选地，也可以在相位补偿OFDM符号中的第k个子载波上承载该站点的导频信号，其中，第k个子载波在第l组子载波中，第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)，1≤z≤M，z取整数，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，此时站点用于发送导频信号的M个OFDM符号中的导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
在本发明实施例中，站点生成的相位补偿OFDM符号可以通过循环移位(CSD)的方式进行复用，即不同站点发送的相位补偿导频信号以及预设的相位补偿导频信号在不同子载波上均满足公式(1)，其中，pm(k)表示站 点在第k个子载波上的相位补偿导频信号或预设相位补偿导频信号，p0为常数，k表示该相位补偿OFDM符号的子载波的序号，Δm表示所示第m个站点的相位偏移系数，可选地，Δm＝CP·m，CP为相位补偿OFDM符号的保护间隔长度。
在本发明实施例中，M表示站点所在的分组的站点的个数。可选地，站点所在的分组内的站点可以属于同一AP或基站。
在S120中，站点向AP发送生成的包括该导频信号的M个OFDM符号，和，包括相位补偿导频信号的相位补偿OFDM符号，以便于AP根据导频信号和相位补偿导频信号确定信道相应信息，并根据信道相应信息确定频率偏差估计值。
应理解，在本发明的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本发明实施例的实施过程构成任何限定。
因此，本发明实施例的无线局域网中处理信号的方法，站点向AP发送包括导频信号的OFDM符号，AP通过确定站点发送导频信号所经过的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，AP解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
图3示出了根据本发明实施例的无线局域网中处理信号的方法200的示意性流程图，该方法200可以由接入点AP执行。如图3所示，该方法200包括：
S210，确定站点发送数据信号所经过的信道的信道响应信息；
S220，根据该信道响应信息，确定该站点的频率偏差估计值；
S230，接收该站点在该信道发送的该数据信号；
S240，根据该信道响应信息和该频率偏差估计值，解析该数据信号。
具体地，AP接收到站点发送的数据信号后，确定该站点发送该数据信号所经过的信道的信道响应信息，根据该信道响应信息确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，对接收到的该站点发送的数据信号进行解析，从而得到接近站点发送的原数据信号。
因此，本发明实施例的无线局域网中处理信号的方法，通过确定站点发 送数据信号所经过的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
在S210中，AP确定站点发送数据信号的信道所经过的信道响应信息。具体地，AP确定承载了站点发送的导频信号的OFDM符号，根据该OFDM符号获得导频信号，根据该导频信号确定该站点的信道响应信息。
在本发明实施例中，站点发送M个OFDM符号，和，相位补偿OFDM符号，M为站点所在分组的站点的个数。可选地，M个OFDM符号可以通过子载波交织的方式进行复用，即对于第m个站点发送的M个OFDM符号，在第i个OFDM符号中的第k个子载波上承载该站点需要发送的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
可选地，在本发明实施例中，M个OFDM符号还可以通过块交织的方式进行复用，即对于第m个站点发送的M个OFDM符号，在第i个OFDM符号中的第k个子载波上承载该站点需要发送的导频信号，其中，第k个子载波在第l组子载波中，该第l组子载波中包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l，L、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
在本发明实施例中，AP确定第m个站点发送的M个OFDM符号上承载的导频信号。具体地，可以直接接收第i个OFDM符号中第k个子载波上的导频信号为第m个站点在第k个子载波上的导频信号。可选地，还可以将第i个OFDM符号进行分离获得第m个站点在第k个子载波上的导频信号。具体地，AP同时接收多个站点发送的导频信号，将该导频信号进行逆傅里叶变换IDFT，再将变换后的导频信号进行滤波处理，最后将该导频信号进行傅里叶变换DFT，得到不同站点的导频信号，不同站点的导频信号彼此分离，分别将各个站点的导频信号分离即可得到第m个站点在第k个子载波上 的导频信号。
在本发明实施例中，AP确定了第m个站点发送的导频信号后，根据预设的导频信号和接收的导频信号的对比，确定该站点的信道响应信息。具体地，可以根据第m个站点在第i个OFDM符号上的接收到的导频信号，和该站点在该OFDM符号上预设的导频信号，通过下面的公式(2)确定第m个站点的第i个信道响应信息：
rm(k)＝Pm(k)*Hm(k)          (2)
其中，rm(k)表示接收到的第m个站点在第i个OFDM符号上的第k个子载波上发送的导频信号，Pm(k)表示第m个站点在第i个OFDM符号上的第k个子载波上预设的导频信号，Hm(k)表示在第k个子载波上第m个站点的第i个信道响应信息。
在S220中，AP根据该信道响应信息，确定该站点的频率偏差估计值。具体地，AP可以先确定站点发送相位补偿导频信号所采用的信道的相位补偿信道响应信息，根据信道响应信息和相位补偿信道响应信息，确定该站点的该频率偏差估计值。
在本发明实施例中，站点发送M个OFDM符号，和，相位补偿OFDM符号，M为站点所在分组的站点的个数。根据S110，对于第m个站点发送的M个OFDM符号，在第i个OFDM符号中的第k个子载波上承载该站点需要发送的导频信号。而对于相位补偿OFDM符号，可选地，可以在该相位补偿OFDM符号中的每个子载波上均承载该站点发送的导频信号，也可以在相位补偿OFDM符号中的第k个子载波上承载该站点的导频信号。
具体地，当站点的导频信号以子载波交织的方式进行复用或以块交织的方式进行复用时，站点在相位补偿OFDM符号中的第k0个子载波以后的每个子载波上承载该站点的导频信号，承载导频信号的第k个子载波满足k0≤k≤N-1。
可选地，当站点的导频信号以子载波交织的方式进行复用时，站点在相位补偿OFDM符号中的第k个子载波上承载该站点的导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，0≤x≤N/M，x取整数，m表示站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。当站点的导频信号以块交织的方 式进行复用时，站点在相位补偿OFDM符号中的第l组子载波中的每个子载波上承载该站点的导频信号，其中，第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)，1≤z≤M，z取整数，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，L、l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。此时，站点用于发送导频信号的M个OFDM符号中的导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
在本发明实施例中，相位补偿OFDM符号通过CSD的方式进行复用，不同站点的预设相位补偿导频信号在不同子载波上均满足公式(1)，其中，pm(k)表示站点在第k个子载波上的该预设相位补偿导频信号，p0为常数，k表示该相位补偿OFDM符号的子载波的序号，Δm表示所示第m个站点的相位偏移系数，可选地，Δm＝CP·m。
在本发明实施例中，AP确定相位补偿OFDM符号的相位补偿导频信号。具体地，当站点在相位补偿OFDM符号中的每个子载波都承载了相位补偿导频信号时，AP在每个子载波上接收到的相位补偿导频信号是属于多个站点的相位补偿导频信号叠加的，可以通过分离分别确定每个站点在各个子载波上的导频信号。当站点只在相位补偿OFDM符号中第k个子载波上承载了相位补偿导频信息时，AP用过CSD复用的方式接收后，每个子载波上承载了不同站点的相位导频符号，同样可以通过分离的方法将每个站点在各个子载波上的导频信号分离出来，得到更准确的相位补偿导频信号。
在本发明实施例中，具体地，可以通过下面的方法进行导频信号的分离。将AP接收到的相位补偿导频信号进行逆傅里叶变换IDFT，得到第一导频信号，再将该第一导频信号进行滤波处理得到第二导频信号，最后将该第二导频信号进行傅里叶变换DFT，得到包括不同站点的相位补偿导频信号的第三导频信号，不同站点的相位补偿导频信号彼此分离，分别将各个站点的相位补偿导频信号分离即可得到相位补偿OFDM符号中第m个站点在第k个子载波上的相位补偿导频信号。
在本发明实施例中，AP确定了第m个站点的相位补偿导频信号后，根据预设的相位补偿导频信号和接收的相位补偿导频信号的对比，确定该站点 的相位补偿信道响应信息。具体地，可以通过的公式(2)确定第m个站点的相位补偿信道响应信息，其中，rm(k)表示第m个站点在相位补偿OFDM符号上的接收到的相位补偿导频信号，Pm(k)表示该站点在该相位补偿OFDM符号上预设相位补偿导频信号，Hm(k)表示第m个站点的相位补偿信道响应信息。
在本发明实施例中，AP根据站点的第i个信道响应信息和相位补偿信道响应信息确定站点的频率偏差估计值。具体地，可以通过确定站点的第i个信道响应信息和相位补偿信道响应信息来确定为该站点的频率偏差估计值，还可以通过站点的M个信道响应信息和相位补偿信道响应信息确定站点的M个频率偏差估计值，将该M个频率偏差估计值的平均值确定为该站点的频率偏差估计值。
在本发明实施例中，可以通过下面的公式(3)确定第m个站点的第i个频率偏差估计值δFm,i：
Figure PCTCN2014091160-appb-000012
其中，m表示站点的序号，1≤m≤M，CP表示该第i个OFDM符号的保护间隔长度，N表示该第i个OFDM符号中子载波的个数，k表示第m个站点在第i个OFDM符号中占用的该子载波的序号，k0≤k≤N-1，k∈Kim表示k分别取第m个站点在该第i个OFDM符号中占用的该子载波的序号，mean{}表示求平均值，angle()表示求相位，Hm,i(k)表示第m个站点的第i个信道响应信息，Hm,M+1(k)表示第m个站点的该相位补偿信道响应信息，
Figure PCTCN2014091160-appb-000013
表示Hm,M+1(k)的共轭。
在S230中，AP接收站点发送的数据信号，该站点通过S110中的信道发送该数据信号。
在S240中，AP根据信道响应信息和该频率偏差估计值，对接收到的数据信号进行解析处理，确定该站点发送的原数据信号。具体地，AP可以根据下面的公式(3)对该数据信号进行解析：
r＝hejφs+n          (3)
其中，r为AP接收到的该站点发送的数据信号，h为该站点的该信道响应信息，s为数据信号的解析结果，该结果可以确定为站点发送的原数据信号，φ为该站点的频率偏差估计值，j为虚数单位，
Figure PCTCN2014091160-appb-000014
n为噪声。根据 该公式，AP可以解析得到更准确更接近站点发送的数据信号。
应理解，在本发明的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本发明实施例的实施过程构成任何限定。
因此，本发明实施例的无线局域网中处理信号的方法，通过确定站点发送数据信号所采用的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
上文中结合图2和图3，从AP的角度详细描述了根据本发明实施例的无线局域网中处理信号的方法，下文中将以几种具体实施例为例，结合图4至图7来描述根据本发明实施例的无线局域网中处理信号的方法。
如图4所示，以4个站点同时发送导频信号为例，4个站点的导频信号以子载波交织的方式进行复用，图4示出了根据本发明实施例的OFDM符号排列的示意图。前4列为该4个站点的OFDM符号，不同颜色代表了不同站点的导频信号；第5列为该4个站点的相位补偿OFDM符号。每个OFDM符号可以包括多个子载波，这里以64个子载波为例进行说明。
在本发明实施例中，AP确定每个站点用于发送导频信号的OFDM符号，第m个站点的第i个OFDM符号的第k个子载波上承载导频信号，其余子载波上为空，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，k0为子载波的起始位置，即k0＝0，mod(a，b)表示a/b取余数。例如，站点1的4个OFDM符号中，在第一个OFDM符号的第k个子载波上承载导频信号，即k＝0、4、8……，在其余子载波上站点1不发送导频信号，该子载波为空。将4个站点的4个OFDM符号进行叠加，得到如图4所示的4个OFDM符号，每个OFDM符号上的一个子载波上承载了一个站点的导频信号，根据该导频信号和预设导频信号进行对比，通过公式(2)可以得到每个站点在每个OFDM符号上每个子载波的信道响应信息。
在本发明实施例中，每个站点还会发送相位补偿导频信号，相位补偿OFDM符号中的每个子载波均承载该相位补偿导频信号，且每个站点的预设相位补偿导频信号满足公式(1)，通过CSD方式进行复用，AP接收到4个站点的相位补偿导频信号，是4个站点在每个子载波上的相位补偿导频信号 进行叠加的结果，得到第5列的OFDM符号为相位补偿OFDM符号。
在本发明实施例中，AP获得的相位补偿OFDM符号中每个子载波上包括了4个站点的相位补偿导频信号，为了获得每个站点的相位补偿导频信号，需要对接收到的导频信号进行分离处理。具体地，将接收到的相位补偿导频信号进行逆傅里叶变换IDFT，然后进行滤波处理，再经过傅里叶变换DFT，即可得到彼此分开的4个站点的相位补偿导频信号。根据相位补偿导频信号和预设的相位补偿导频信号，通过公式(2)即可获得每个站点在第k个子载波上的相位补偿信道响应信息。
在本发明实施例中，根据公式(3)即可获得每个站点相对于每个OFDM符号的频率偏差估计值，其中，m表示站点的序号，1≤m≤4，CP表示OFDM符号的保护间隔长度，N表示每个OFDM符号中子载波的个数，N＝64，k表示第m个站点发送导频信号在第i个OFDM符号中占用的子载波的序号，k0≤k≤N-1，即0≤k≤63，k∈Kim表示k分别取第m个站点在该第i个OFDM符号中占用的所有子载波的序号，mean{}表示求平均值，angle()表示求相位，Hm,i(k)表示第m个站点的第i个信道响应信息，Hm,M+1(k)表示第m个站点的该相位补偿信道响应信息，
Figure PCTCN2014091160-appb-000015
表示Hm，M+1(k)的共轭。
在本发明实施例中，根据该公式(3)可以分别求出每个站点对于4个OFDM符号的4个频率偏差估计值，可选地，可以将其中一个频率偏差估计直接作为该站点的平率偏差估计值，也可以确定4个频率偏差估计值的平均值为该站点的频率偏差估计值。
在本发明实施例中，AP分别确定每个站点的频率偏差估计值，根据每个站点的频率偏差估计值和信道响应信息对接收的该站点的数据信号进行解析处理，从而获得解析后的数据信号。
因此，本发明实施例的无线局域网中处理信号的方法，通过确定站点发送数据信号所采用的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
如图5所示，仍然以4个站点同时发送导频信号为例，4个站点的导频信号以块交织的方式进行复用，图5示出了根据本发明实施例的OFDM符号排列的另一示意图。前4列为该4个站点的OFDM符号，不同颜色代表 了不同站点的导频信号；第5列为该4个站点的相位补偿OFDM符号。每个OFDM符号可以包括多个子载波，这里以64个子载波为例进行说明，每个4个子载波为一组，共16组子载波。
在本发明实施例中，AP确定每个站点用于发送导频信号的OFDM符号，第m个站点的第i个OFDM符号的第l组子载波上承载导频信号，第l组子载波包括L个子载波，子载波的序号为k，其余子载波上为空，其中，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，l为整数，m表示该站点的序号，k0为子载波的起始位置，k0＝0，mod(a，b)表示a/b取余数。例如，站点1的4个OFDM符号中，在第一个OFDM符号的第l组子载波上承载导频信号，即l＝0、1、2、3、4……，则k＝0、1、2、3、16、17、18、19……，在其余子载波上站点1不发送导频信号，该子载波为空。将4个站点的4个OFDM符号进行叠加，得到如图5所示的4个OFDM符号，每个OFDM符号上的每个子载波组上承载了一个站点的导频信号，每个子载波组包括4个子载波，根据该导频信号和预设导频信号进行对比，通过公式(2)可以得到每个站点在每个OFDM符号上每个子载波的信道响应信息。
在本发明实施例中，每个站点还会发送相位补偿导频信号，相位补偿OFDM符号中的每个子载波均承载该相位补偿导频信号，且每个站点的预设相位补偿导频信号满足公式(1)，通过CSD方式进行复用，AP接收到4个站点的相位补偿导频信号，是4个站点在每个子载波上的相位补偿导频信号进行叠加的结果，得到第5列的OFDM符号为相位补偿OFDM符号。
在本发明实施例中，AP获得的相位补偿OFDM符号中每个子载波上包括了4个站点的相位补偿导频信号，为了获得每个站点的相位补偿导频信号，需要对接收到的导频信号进行分离处理。具体地，将接收到的相位补偿导频信号进行逆傅里叶变换IDFT，然后进行滤波处理，再经过傅里叶变换DFT，即可得到彼此分开的4个站点的相位补偿导频信号。根据相位补偿导频信号和预设的相位补偿导频信号，通过公式(2)可获得每个站点在第k个子载波上的相位补偿信道响应信息。
在本发明实施例中，根据公式(3)即可获得每个站点相对于每个OFDM符号的频率偏差估计值，其中，m表示站点的序号，1≤m≤4，CP表示OFDM符号的保护间隔长度，N表示每个OFDM符号中子载波的个数，N＝64，k 表示第m个站点发送导频信号在第i个OFDM符号中占用的子载波的序号，k0≤k≤N-1，即0≤k≤63，k∈Kim表示k分别取第m个站点在该第i个OFDM符号中占用的所有子载波的序号，mean{}表示求平均值，angle()表示求相位，Hm，i(k)表示第m个站点的第i个信道响应信息，Hm，M+1(k)表示第m个站点的该相位补偿信道响应信息，
Figure PCTCN2014091160-appb-000016
表示Hm,M+1(k)的共轭。
在本发明实施例中，根据该公式(3)可以分别求出每个站点对于4个OFDM符号的4个频率偏差估计值，可选地，可以将其中一个频率偏差估计直接作为该站点的平率偏差估计值，也可以确定4个频率偏差估计值的平均值为该站点的频率偏差估计值。
在本发明实施例中，AP分别确定每个站点的频率偏差估计值后，根据每个站点的频率偏差估计值和信道响应信息对接收的该站点的数据信号进行解析处理，从而获得解析后的数据信号。
因此，本发明实施例的无线局域网中处理信号的方法，通过确定站点发送数据信号所采用的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
如图6所示，以4个站点同时发送导频信号为例，4个站点的导频信号以子载波交织的方式进行复用，图6示出了根据本发明实施例的OFDM符号排列的再一示意图。前4列为该4个站点的OFDM符号，第5列为该4个站点的相位补偿OFDM符号，每一列的OFDM符号中的不同颜色代表了不同子载波上承载了不同站点的导频信号。每个OFDM符号可以包括多个子载波，这里以64个子载波为例进行说明。
在本发明实施例中，AP确定每个站点用于发送导频信号的OFDM符号，第m个站点的第i个OFDM符号的第k个子载波上承载导频信号，其余子载波上为空，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，k0为子载波的起始位置，k0＝0，mod(a，b)表示a/b取余数。例如，站点1的4个OFDM符号中，在第一个OFDM符号的第k个子载波上承载导频信号，即k＝0、4、8……，在其余子载波上站点1不发送导频信号，该子载波为空。将4个站点的4个OFDM符号进行叠加，得到如图6所示的4个OFDM符号，每个OFDM符号上的一个子载波上承载了一个站点的导频 信号。此时，站点用于发送导频信号的M个OFDM符号中的导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
在本发明实施例中，每个站点还会发送相位补偿导频信号，相位补偿OFDM符号中的第k个子载波上承载该相位补偿导频信号，其余为空，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，i＝1，0≤x≤N/M，x取整数，mod(a，b)表示a/b取余数，k0为子载波的起始位置，k0＝0。例如，站点1发送的相位补偿导频信号在第k个子载波上，k＝0、4、8……，在其余子载波上站点1不发送相位补偿导频信号，该子载波为空。将4个站点的相位补偿导频信号进行叠加，得到第5列的OFDM符号为相位补偿OFDM符号。对于每个站点的预设相位补偿导频信号满足公式(1)，通过CSD方式进行复用，AP接收4个站点的相位补偿导频信号。
在本发明实施例中，AP获得的4个OFDM符号和1个相位补偿OFDM符号中的不同子载波上承载的不同的站点的导频信号和相位补偿导频信号，为了更准确地获得每个站点的导频信号和相位补偿导频信号，需要对接收到的导频信号和相位补偿导频信号进行分离处理。具体地，将接收到的每个OFDM符号上的导频信号或相位补偿导频信号分别先进行逆傅里叶变换IDFT，然后进行滤波处理，再经过傅里叶变换DFT，即可得到每个OFDM符号中彼此分开的4个站点的导频信号和相位补偿导频信号。
在本发明实施例中，根据分离得到的每个站点在第1个OFDM符号中的导频信号和相位补偿导频信号，根据预设的导频信号和预设的相位补偿导频信号，通过公式(2)可获得每个站点对于第1个OFDM符号在第k个子载波上的信道响应信息和对于相位补偿OFDM符号在第k个子载波上的相位补偿信道响应信息。
在本发明实施例中，根据公式(3)即可获得每个站点相对于第1个OFDM符号的频率偏差估计值，其中，i表示OFDM符号的序号，取i＝1，m表示站点的序号，1≤m≤4，CP表示OFDM符号的保护间隔长度，N表示每个OFDM符号中子载波的个数，N＝64，k表示第m个站点发送导频信号在第1个OFDM符号中占用的子载波的序号，k0≤k≤N-1，即0≤k≤63，k∈Kim表示k分别取该站点在该第i个OFDM符号中占用的该子载波的序号， mean{}表示求平均值，angle()表示求相位，Hm,i(k)表示该站点的第i个信道响应信息，Hm,M+1(k)表示该站点的该相位补偿信道响应信息，
Figure PCTCN2014091160-appb-000017
表示Hm,M+1(k)的共轭。
在本发明实施例中，根据该公式(3)可以分别求出每个站点对于第1个OFDM符号的频率偏差估计值，可以将该频率偏差估计值确定为该站点的频率偏差估计值。
在本发明实施例中，AP分别确定每个站点的频率偏差估计值，根据每个站点的频率偏差估计值和信道响应信息对接收的该站点的数据信号进行解析处理，从而获得解析后的数据信号。
因此，本发明实施例的无线局域网中处理信号的方法，通过确定站点发送数据信号所采用的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
如图7所示，仍然以4个站点同时发送导频信号为例，4个站点的导频信号以块交织的方式进行复用，图7示出了根据本发明实施例的OFDM符号排列的再一示意图。前4列为该4个站点的OFDM符号，第5列为该4个站点的相位补偿OFDM符号，每一列的OFDM符号中的不同颜色代表了不同子载波上承载了不同站点的导频信号。每个OFDM符号可以包括多个子载波，这里以64个子载波为例进行说明，每个4个子载波为一组，共16组子载波，图7中不同OFDM符号中每块代表一组子载波，每组4个子载波。
在本发明实施例中，AP确定每个站点用于发送导频信号的OFDM符号，第m个站点的第i个OFDM符号的第l组子载波上承载导频信号，第l组子载波包括L个子载波，子载波的序号为k，其余子载波上为空，其中，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，l为整数，m表示该站点的序号，k0为子载波的起始位置，即k0＝0，mod(a，b)表示a/b取余数。例如，站点1的4个OFDM符号中，在第一个OFDM符号的第L组子载波上承载导频信号，即l＝0、1、2、3、4……，则k＝0、1、2、3、16、17、18、19……，在其余子载波上站点1不发送导频信号，该子载波为空。将4个站点的4个 OFDM符号进行叠加，得到如图7所示的4个OFDM符号，每个OFDM符号上的每个子载波组上承载了一个站点的导频信号，每个子载波组包括4个子载波。此时，站点用于发送导频信号的M个OFDM符号中的导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
在本发明实施例中，每个站点还会发送相位补偿导频信号，相位补偿OFDM符号中的第L组子载波中每个子载波上承载导频信号，第L组子载波包括l个子载波，子载波的序号为k，其余子载波上为空，其中，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)，1≤z≤M，z取整数，i＝1，0≤x<L，x取整数，mod(a，b)表示a/b取余数，0≤l≤N/(L*M)，L为大于或等于2的整数，l取整数m表示该站点的序号。例如，站点1的相位补偿OFDM符号中，在第l组子载波中的每个子载波上承载导频信号，即l＝0、1、2、3、4……，则k＝0、1、2、3、16、17、18、19……，在其余子载波上站点1不发送相位补偿导频信号，该子载波为空。将4个站点的相位补偿导频信号进行叠加，得到第5列的OFDM符号为相位补偿OFDM符号。对于每个站点的预设相位补偿导频信号满足公式(1)，通过CSD方式进行复用，AP接收到4个站点的相位补偿导频信号。
在本发明实施例中，AP获得的4个OFDM符号和1个相位补偿OFDM符号中的不同子载波上承载的不同的站点的导频信号和相位补偿导频信号，为了更准确地获得每个站点的导频信号和相位补偿导频信号，需要对接收到的导频信号和相位补偿导频信号进行分离处理。具体地，将接收到的每个OFDM符号上的导频信号或相位补偿导频信号分别先进行逆傅里叶变换IDFT，然后进行滤波处理，再经过傅里叶变换DFT，即可得到每个OFDM符号中彼此分开的4个站点的导频信号和相位补偿导频信号。
在本发明实施例中，根据分离得到的每个站点相对于第1个OFDM符号中的导频信号和相位补偿导频信号，根据预设的导频信号和预设的相位补偿导频信号，通过公式(2)可获得每个站点对于第1个OFDM符号在第k个子载波上的信道响应信息和对于相位补偿OFDM符号在第k个子载波上的相位补偿信道响应信息。
在本发明实施例中，根据公式(3)即可获得每个站点相对于第一个 OFDM符号的频率偏差估计值，其中，i表示OFDM符号的序号，取i＝1，m表示站点的序号，1≤m≤4，CP表示OFDM符号的保护间隔长度，N表示每个OFDM符号中子载波的个数，N＝64，k表示第m个站点发送导频信号在第i个OFDM符号中占用的子载波的序号，k0≤k≤N-1，即0≤k≤63，k∈Kim表示k分别取该站点在该第i个OFDM符号中占用的该子载波的序号，mean{}表示求平均值，angle()表示求相位，Hm,i(k)表示该站点的第i个信道响应信息，Hm,M+1(k)表示该站点的该相位补偿信道响应信息，
Figure PCTCN2014091160-appb-000018
表示Hm,M+1(k)的共轭。
在本发明实施例中，根据该公式(3)可以求出每个站点对于第1个OFDM符号的频率偏差估计值，将该频率偏差估计值确定为该站点的频率偏差估计值。
在本发明实施例中，AP分别确定每个站点的频率偏差估计值后，根据每个站点的频率偏差估计值和信道响应信息对接收的该站点的数据信号进行解析处理，从而获得解析后的数据信号。
应理解，在本发明的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本发明实施例的实施过程构成任何限定。
因此，本发明实施例的无线局域网中处理信号的方法，通过确定站点发送数据信号所采用的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
上文中结合图1至图7，详细描述了根据本发明实施例的无线局域网中处理信号的方法，下面将结合图8和图9，描述根据本发明实施例的站点和AP。
图8示出了根据本发明实施例的无线局域网中的站点300的示意性流程图。如图8所示，该站点300包括：
生成模块310，用于生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，该M为站点所在分组的站点的个数，该相位补偿OFDM符号中的该相位补偿导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该相位补偿导频信号，p0 为常数，m表示该站点的序号，k表示该相位补偿OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；
发送模块320，用于向AP发送包括该导频信号的该M个OFDM符号，和，包括该相位补偿导频信号的该相位补偿OFDM符号，以便于AP确定频率偏差估计值。
因此，本发明实施例的无线局域网中的站点，将包括导频信号的OFDM符号发送至AP，AP通过确定站点发送导频信号所经过的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，AP解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
在本发明实施例中，站点的生成模块310生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号。可选地，M个OFDM符号和相位补偿OFDM符号可以通过子载波交织的方式进行复用。具体地，对于第m个站点发送的M个OFDM符号，在第i个OFDM符号中的第k个子载波上承载该站点需要发送的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。而对于相位补偿OFDM符号，可选地，站点可以在该相位补偿OFDM符号中的第k个子载波上均承载该站点发送的导频信号，其中，k0≤k≤N-1。可选地，也可以在相位补偿OFDM符号中的第k个子载波上承载该站点的导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，k0为子载波的起始位置，0≤x≤N/M，x取整数，此时站点用于发送导频信号的M个OFDM符号中的导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
可选地，在本发明实施例中，生成模块310生成的M个OFDM符号和相位补偿OFDM符号还可以通过块交织的方式进行复用。具体地，对于第m个站点发送的M个OFDM符号，在第i个OFDM符号中的第k个子载波上承载该站点需要发送的导频信号，其中，第k个子载波在第l组子载波中， 该第l组子载波中包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l，L、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。而对于相位补偿OFDM符号，可选地，站点可以在该相位补偿OFDM符号中的第k个子载波上均承载该站点发送的导频信号，其中，k0≤k≤N-1。可选地，也可以在相位补偿OFDM符号中的第k个子载波上承载该站点的导频信号，其中，第k个子载波在第l组子载波中，第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)，1≤z≤M，z取整数，，0≤x<L，x取整数，k0为子载波的起始位置，0≤l≤N/(L*M)，L为大于或等于2的整数，此时站点用于发送导频信号的M个OFDM符号中的导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
在本发明实施例中，站点的生成模块310生成的相位补偿OFDM符号可以通过CSD的方式进行复用，即不同站点发送的相位补偿导频信号以及预设的相位补偿导频信号在不同子载波上均满足的公式(1)，其中，pm(k)表示站点在第k个子载波上的相位补偿导频信号或预设相位补偿导频信号，p0为常数，k表示该相位补偿OFDM符号的子载波的序号，Δm表示所示第m个站点的相位偏移系数，可选地，Δm＝CP·m，CP为相位补偿OFDM符号的保护间隔长度。
在本发明实施例中，站点的发送模块向AP发送生成模块310生成的包括该导频信号的M个OFDM符号和包括相位补偿导频信号的相位补偿OFDM符号，以便于AP根据导频信号和相位补偿导频信号确定信道相应信息，并根据信道相应信息确定频率偏差估计值。
应理解，根据本发明实施例的站点300可对应于执行本发明实施例中的方法的100，并且站点300中的各个模块的上述和其它操作和/或功能分别为了实现图2中的各个方法的相应流程，为了简洁，在此不再赘述。
因此，本发明实施例的无线局域网中的站点，将包括导频信号的OFDM符号发送至AP，AP通过确定站点发送导频信号所经过的信道的信道响应信 息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，AP解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
如图9所示，根据本发明实施例的无线局域网中的接入点400包括：
第一确定模块410，用于确定站点发送数据信号所经过的信道的信道响应信息；
第二确定模块420，用于根据该信道响应信息，确定该站点的频率偏差估计值；
接收模块430，用于接收该站点在该信道发送的该数据信号；
处理模块440，用于根据该信道响应信息和该频率偏差估计值，解析该数据信号。
因此，本发明实施例的无线局域网中的接入点，通过确定站点发送数据信号所采用的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
在本发明实施例中，AP的第一确定模块410确定站点发送数据信号所采用的信道的信道响应信息。具体地，AP的第一确定模块410确定站点发送导频信号所经过的OFDM符号，根据该OFDM符号获得导频信号，根据该导频信号确定该站点的信道响应信息。
在本发明实施例中，站点发送M个OFDM符号和一个相位补偿OFDM符号，M为站点所在分组的站点的个数。可选地，M个OFDM符号可以通过子载波交织的方式进行复用，即对于第m个站点发送的M个OFDM符号，在第i个OFDM符号中的第k个子载波上承载该站点需要发送的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
可选地，在本发明实施例中，M个OFDM符号还可以通过块交织的方式进行复用，即对于第m个站点发送的M个OFDM符号，在第i个OFDM 符号中的第k个子载波上承载该站点需要发送的导频信号，其中，第k个子载波在第l组子载波中，该第l组子载波中包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，L、l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
在本发明实施例中，AP的第一确定模块410确定第m个站点发送的M个OFDM符号上承载的导频信号。具体地，可以直接接收第i个OFDM符号中第k个子载波上的导频信号确定为第m个站点在第k个子载波上的导频信号。可选地，还可以将第i个OFDM符号进行分离获得第m个站点在第k个子载波上的导频信号。具体地，AP同时接收多个站点发送的导频信号，将该导频信号进行逆傅里叶变换IDFT，再将变换后的导频信号进行滤波处理，最后将该导频信号进行傅里叶变换DFT，得到不同站点的导频信号，不同站点的导频信号彼此分离，分别将各个站点的导频信号分离即可得到第m个站点在第k个子载波上的导频信号。
在本发明实施例中，AP的第一确定模块410确定了第m个站点发送的导频信号后，根据预设的导频信号和接收的导频信号的对比，确定该站点的信道响应信息。具体地，可以根据第m个站点在第i个OFDM符号上的接收到的导频信号，和该站点在该OFDM符号上预设的导频信号，通过公式(2)确定第m个站点的第i个信道响应信息，其中，rm(k)表示接收到的第m个站点在第i个OFDM符号上的第k个子载波上发送的导频信号，Pm(k)表示第m个站点在第i个OFDM符号上的第k个子载波上预设的导频信号，Hm(k)表示在第k个子载波上第m个站点的第i个信道响应信息。
在本发明实施例中，不同站点的预设相位补偿导频信号在不同子载波上满足公式(1)，其中，Pm(k)为第m个站点在第k个子载波上的预设相位补偿导频信号，P0(k)为常数，为幅度为1的基本导频信号，可选地，P0(k)＝1，CP为相位补偿OFDM符号的保护间隔长度，j为虚数单位，
在本发明实施例中，AP根据第一确定模块410确定的该信道响应信息，通过第二确定模块420确定该站点的频率偏差估计值。具体地，AP可以先通过第一确定模块410确定站点发送相位补偿导频信号所采用的信道的相位补偿信道响应信息，根据第一确定模块410确定的信道响应信息和相位补偿 信道响应信息，通过第二确定模块420确定该站点的该频率偏差估计值。
在本发明实施例中，站点发送M个OFDM符号和一个相位补偿OFDM符号，M为站点所在分组的站点的个数。根据第一确定模块410确定的第m个站点发送的M个OFDM符号，在第i个OFDM符号中的第k个子载波上承载该站点需要发送的导频信号。而对于相位补偿OFDM符号，可选地，可以在该相位补偿OFDM符号中的每个子载波上均承载该站点发送的导频信号，也可以在相位补偿OFDM符号中的第k个子载波上承载该站点的导频信号。
具体地，当站点的导频信号以子载波交织的方式进行复用或以块交织的方式进行复用时，站点在相位补偿OFDM符号中的第k0个子载波以后的每个子载波上承载该站点的导频信号，承载导频信号的第k个子载波满足k0≤k≤N-1。
可选地，当站点的导频信号以子载波交织的方式进行复用时，站点在相位补偿OFDM符号中的第k个子载波上承载该站点的导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，x取整数，m表示站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。当站点的导频信号以块交织的方式进行复用时，站点在相位补偿OFDM符号中的第l组子载波中的每个子载波上承载该站点的导频信号，其中，第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)1≤z≤M，z取整数，0≤x≤N/M，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，k0≤k≤N-1，m表示站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，L、l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。可选地，站点用于发送导频信号的M个OFDM符号中的导频信号可以满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
在本发明实施例中，相位补偿OFDM符号通过循环移位(CSD)的方式进行复用，不同站点的预设相位补偿导频信号在不同子载波上均满足下面的公式(1)，其中，pm(k)为第m个站点在第k个子载波上的相位补偿导频 信号，p0为常数，表示幅度为1的基本导频信号，CP为相位补偿OFDM符号的保护间隔长度，j为虚数单位，
Figure PCTCN2014091160-appb-000020
对于每个站点的预设相位补偿导频信号同样满足公式(1)。
在本发明实施例中，AP的第一确定模块410还可以确定相位补偿OFDM符号的相位补偿导频信号。具体地，当站点在相位补偿OFDM符号中的每个子载波都承载了相位补偿导频信号时，AP在每个子载波上接收到的相位补偿导频信号是属于多个站点的相位补偿导频信号叠加的，可以通过分离分别确定每个站点在各个子载波上的导频信号。当站点只在相位补偿OFDM符号中第k个子载波上承载相位补偿导频信息时，AP用过CSD复用的方式接收后，每个子载波上承载了不同站点的相位导频符号，同样可以通过分离的方法将每个站点在各个子载波上的导频信号分离出来，得到更准确的相位补偿导频信号。
在本发明实施例中，具体地，可以通过下面的方法进行导频信号的分离。将AP接收到的相位补偿导频信号进行逆傅里叶变换IDFT，得到第一导频信号，再将该第一导频信号进行滤波处理得到第二导频信号，最后将该第二导频信号进行傅里叶变换DFT，得到包括不同站点的相位补偿导频信号的第三导频信号，不同站点的相位补偿导频信号彼此分离，分别将各个站点的相位补偿导频信号分离即可得到相位补偿OFDM符号中第m个站点在第k个子载波上的相位补偿导频信号。
在本发明实施例中，AP的第一确定模块410确定了第m个站点的相位补偿导频信号后，根据预设的相位补偿导频信号和接收的相位补偿导频信号的对比，确定该站点的相位补偿信道响应信息。具体地，可以通过的公式(2)确定第m个站点的相位补偿信道响应信息，其中，rm(k)表示第m个站点在相位补偿OFDM符号上的接收到的相位补偿导频信号，Pm(k)表示该站点在该相位补偿OFDM符号上预设相位补偿导频信号，Hm(k)表示第m个站点的相位补偿信道响应信息。
在本发明实施例中，AP根据第一确定模块410确定的站点的第i个信道响应信息和相位补偿信道响应信息，由第二确定模块420确定站点的频率偏差估计值。具体地，可以通过确定站点的第i个信道响应信息和相位补偿信道响应信息来确定为该站点的频率偏差估计值，还可以通过站点的M个信道响应信息和相位补偿信道响应信息确定站点的M个频率偏差估计值， 将该M个频率偏差估计值的平均值确定为该站点的频率偏差估计值。
具体地，可以通过公式(3)确定第m个站点的第i个频率偏差估计值δFm,i，其中，m表示站点的序号，1≤m≤M，CP表示该第i个OFDM符号的保护间隔长度，N表示该第i个OFDM符号中子载波的个数，k表示第m个站点在第i个OFDM符号中占用的该子载波的序号，k0≤k≤N-1，k∈Kim表示k分别取该站点在该第i个OFDM符号中占用的该子载波的序号，mean{}表示求平均值，angle()表示求相位，Hm,i(k)表示该站点的第i个信道响应信息，Hm,M+1(k)表示该站点的该相位补偿信道响应信息，
Figure PCTCN2014091160-appb-000021
表示Hm,M+1(k)的共轭。
在本发明实施例中，AP通过接收模块430接收站点通过信道发送的数据信号。
在本发明实施例中，根据第一确定模块410确定的信道响应信息和第二确定模块420确定的频率偏差估计值，AP的处理模块440对接收模块230接收到的数据信号进行解析处理，确定该站点发送的原数据信号。具体地，AP可以根据公式(3)通过处理模块440对该数据信号进行解析，其中，r为AP接收到的该站点发送的数据信号，h为该站点的该信道响应信息，s为数据信号的解析结果，该结果可以确定为站点发送的原数据信号，φ为该站点的频率偏差估计值，j为虚数单位，
Figure PCTCN2014091160-appb-000022
n为噪声。根据该公式，AP可以解析得到更准确更接近站点发送的数据信号。
应理解，根据本发明实施例的AP400可对应于执行本发明实施例中的方法的200，并且AP400中的各个模块的上述和其它操作和/或功能分别为了实现图3中的各个方法的相应流程，为了简洁，在此不再赘述。
另外，本文中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本文中字符“/”，一般表示前后关联对象是一种“或”的关系。
因此，本发明实施例的无线局域网中的接入点，通过确定站点发送数据信号所采用的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
如图10所示，本发明实施例还提供了一种无线局域网中的站点500，该站点500包括处理器510、存储器520、发送器530和总线系统540。其中，处理器510、存储器520和接收器530通过总线系统540相连，该存储器520用于存储指令，该处理器510用于执行该存储器520存储的指令，以控制接收器330接收信号。其中，该处理器510用于生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，该M为站点所在分组的站点的个数，该相位补偿OFDM符号中的该相位补偿导频信号满足下面的公式(1)，其中，pm(k)表示该站点在第k个子载波上的该相位补偿导频信号，p0为常数，k表示该相位补偿OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；发送器530用于向AP发送包括该导频信号的该M个OFDM符号，和，包括该相位补偿导频信号的该相位补偿OFDM符号，以便于AP确定频率偏差估计值。
因此，本发明实施例的无线局域网中的站点，将包括导频信号的OFDM符号发送至AP，AP通过确定站点发送导频信号所经过的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，AP解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
应理解，在本发明实施例中，该处理器510可以是中央处理单元(Central Processing Unit，简称为“CPU”)，该处理器510还可以是其他通用处理器、数字信号处理器(DSP)、专用集成电路(ASIC)、现成可编程门阵列(FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。
该存储器520可以包括只读存储器和随机存取存储器，并向处理器510提供指令和数据。存储器520的一部分还可以包括非易失性随机存取存储器。例如，存储器520还可以存储设备类型的信息。
该总线系统540除包括数据总线之外，还可以包括电源总线、控制总线和状态信号总线等。但是为了清楚说明起见，在图中将各种总线都标为总线系统540。
在实现过程中，上述方法的各步骤可以通过处理器510中的硬件的集成 逻辑电路或者软件形式的指令完成。结合本发明实施例所公开的方法的步骤可以直接体现为硬件处理器执行完成，或者用处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器520，处理器510读取存储器520中的信息，结合其硬件完成上述方法的步骤。为避免重复，这里不再详细描述。
可选地，作为一个实施例，该处理器510还用于确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上均承载该站点的该相位补偿导频信号，其中k0≤k≤N-1，k0为子载波的起始位置。
可选地，作为一个实施例，该处理器510还用于确定该M个OFDM符号，该M个OFDM符号中的该导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，k0为子载波的起始位置，x取整数，mod(a，b)表示a/b取余数。
可选地，作为一个实施例，该处理器510还用于确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序 号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k子载波上均承载该站点的该相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
可选地，作为一个实施例，该处理器510还用于确定该M个OFDM符号，该M个OFDM符号中的该导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数；该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，L为大于或等于2的整数，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，1≤z≤M，z取整数，l取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
应理解，根据本发明实施例的站点5500可对应于本发明实施例中的站点300，并可以对应于执行根据本发明实施例的方法100中的相应主体，并且站点500中的各个模块的上述和其它操作和/或功能分别为了实现图2中的各个方法的相应流程，为了简洁，在此不再赘述。
因此，本发明实施例的无线局域网中的站点，将包括导频信号的OFDM符号发送至AP，AP通过确定站点发送导频信号所经过的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，AP解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
如图11所示，本发明实施例还提供了一种无线局域网中的接入点600，该接入点600包括处理器610、存储器620、接收器630和总线系统640。其中，处理器610、存储器620和接收器630通过总线系统640相连，该存储器620用于存储指令，该处理器610用于执行该存储器620存储的指令，以控制接收器630接收信号。其中，该处理器610用于确定站点发送数据信号所经过的信道的信道响应信息；根据该信道响应信息，确定该站点的频率偏差估计值；接收器630用于接收该站点在该信道发送的该数据信号；再由处理器610根据该信道响应信息和该频率偏差估计值，解析该数据信号。
因此，本发明实施例的无线局域网中的接入点，通过确定站点发送数据信号所采用的信道的信道响应信息来确定该站点的频率偏差估计值，根据该信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
应理解，在本发明实施例中，该处理器610可以是中央处理单元(Central Processing Unit，简称为“CPU”)，该处理器610还可以是其他通用处理器、数字信号处理器(DSP)、专用集成电路(ASIC)、现成可编程门阵列(FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。
该存储器620可以包括只读存储器和随机存取存储器，并向处理器610提供指令和数据。存储器620的一部分还可以包括非易失性随机存取存储器。例如，存储器620还可以存储设备类型的信息。
该总线系统640除包括数据总线之外，还可以包括电源总线、控制总线和状态信号总线等。但是为了清楚说明起见，在图中将各种总线都标为总线系统640。
在实现过程中，上述方法的各步骤可以通过处理器610中的硬件的集成逻辑电路或者软件形式的指令完成。结合本发明实施例所公开的方法的步骤可以直接体现为硬件处理器执行完成，或者用处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器620，处理器610读取存储器620中的信息，结合其 硬件完成上述方法的步骤。为避免重复，这里不再详细描述。
可选地，作为一个实施例，该处理器610还用于确定该站点发送相位补偿导频信号所经过的信道的相位补偿信道响应信息；根据该信道响应信息和该相位补偿信道响应信息，确定该站点的该频率偏差估计值。
可选地，作为一个实施例，该处理器610还用于确定该站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，该M为站点所在分组的站点的个数；根据该M个OFDM符号中的第i个OFDM符号，将该站点发送该第i个OFDM符号中的导频信号所经过的信道的信道响应信息确定为第i个信道响应信息，i取正整数，1≤i≤M；根据该相位补偿OFDM符号，确定该站点发送该相位补偿OFDM符号中的相位补偿导频信号所经过的信道的该相位补偿信道响应信息；根据该站点的该第i个信道响应信息和该相位补偿信道响应信息，确定该站点的该频率偏差估计值。
可选地，作为一个实施例，该处理器610还用于根据该站点的M个信道响应信息和该相位补偿信道响应信息，确定该站点的M个频率偏差估计值；确定该站点的该M个频率偏差估计值的平均值为该站点的该频率偏差估计值。
可选地，作为一个实施例，该处理器610还用于确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k子载波上均承载该站点的该相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
可选地，作为一个实施例，该处理器610还用于确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿 OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，x取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
可选地，作为一个实施例，该处理器610还用于确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k子载波上均承载该站点的该相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
可选地，作为一个实施例，该处理器610还用于确定该M个OFDM符号，该M个OFDM符号中的该第i个OFDM符号中的第k个子载波上承载该站点的导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示该站点的序号，1≤m≤M，k0≤k≤N-1，N表示该第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；确定该相位补偿OFDM符号，该相位补偿OFDM符号中的第k个子载波上承载该站点的该相位补偿导频信号，其中，该第k个子载波在第l组子载波中，该第l组子载波包括L个子载波，L为大于或等于2的整数，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)，1≤z≤M，z取整数，0≤x<L，x取整数，0≤l≤N/(L*M)，l取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
可选地，作为一个实施例，该处理器610还用于确定该相位补偿OFDM符号，该站点的该相位补偿OFDM符号中的该相位补偿导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该相位补偿导频信号，p0为常数，k表示该相位补偿OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
可选地，作为一个实施例，该处理器610还用于确定该M个OFDM符号，该M个OFDM符号中的该导频信号满足公式(1)，其中，pm(k)表示该站点在第k个子载波上的该导频信号，p0为常数，k表示该OFDM符号的子载波的序号，Δm表示该站点的相位偏移系数。
可选地，作为一个实施例，该处理器610还用于根据公式(3)确定该站点的该频率偏差估计值，其中，δFm,i表示该站点的第i个频率偏差估计值，m表示该站点的序号，1≤m≤M，CP表示该第i个OFDM符号的保护间隔长度，N表示该第i个OFDM符号中的子载波的个数，k表示该站点在第i个OFDM符号中占用的该子载波的序号，k0≤k≤N-1，k∈Kim表示k分别取该站点在该第i个OFDM符号中占用的该子载波的序号，mean{}表示求平均值，angle()表示求相位，Hm,i(k)表示该站点的第i个信道响应信息，Hm,M+1(k)表示该站点的该相位补偿信道响应信息，
Figure PCTCN2014091160-appb-000023
表示Hm，M+1(k)的共轭。
可选地，作为一个实施例，该处理器610还用于确定该站点发送的该M个OFDM符号中的第i个OFDM符号中的接收导频信号；根据第i个预设导频信号和该第i个OFDM符号中的接收导频信号确定该站点的该第i个信道响应信息；确定该站点发送的该相位补偿OFDM符号中的该相位补偿导频信号；根据预设相位补偿导频信号和该相位补偿导频信号，确定该站点的该相位补偿信道响应信息。
可选地，作为一个实施例，该处理器610还用于接收多个站点发送的相位补偿OFDM符号中的导频信号；将该导频信号进行逆傅里叶变换IDFT，确定第一导频信号；将该第一导频信号进行滤波处理，确定第二导频信号；将该第二导频信号进行傅里叶变换DFT，确定第三导频信号；根据该第三导频信号，确定该站点发送的该相位补偿OFDM符号中的该相位补偿导频信号。
应理解，根据本发明实施例的接入点600可对应于本发明实施例中的接入点400，并可以对应于执行根据本发明实施例的方法200中的相应主体，并且接入点600中的各个模块的上述和其它操作和/或功能分别为了实现图3中的各个方法的相应流程，为了简洁，在此不再赘述。
因此，本发明实施例的无线局域网中的接入点，通过确定站点发送数据信号所采用的信道的信道响应信息来确定该站点的频率偏差估计值，根据该 信道响应信息和频率偏差估计值，从而解析接收到的数据信号，可以避免多个站点之间的频率偏差的影响，使得解析得到的数据信号更准确，减少了数据信号解析的误码率，进而增强了系统的接收性能。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本发明的范围。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的系统、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本发明各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。
所述功能如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本发明的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本发明各个实施例所述方法的全部或部分步骤。而前 述的存储介质包括：U盘、移动硬盘、只读存储器(ROM，Read-Only Memory)、随机存取存储器(RAM，Random Access Memory)、磁碟或者光盘等各种可以存储程序代码的介质。
以上所述，仅为本发明的具体实施方式，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本发明的保护范围之内。因此，本发明的保护范围应所述以权利要求的保护范围为准。

Claims (36)

  1. 一种无线局域网中处理信号的方法，其特征在于，包括：
    生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，所述M为站点所在分组的站点的个数，所述相位补偿OFDM符号中的所述相位补偿导频信号满足下面的公式(1)：
    Figure PCTCN2014091160-appb-100001
    其中，pm(k)表示所述站点在第k个子载波上的所述相位补偿导频信号，p0为常数，k表示所述相位补偿OFDM符号的子载波的序号，Δm表示所述站点的相位偏移系数；
    向接入点发送包括所述导频信号的所述M个OFDM符号，和。包括所述相位补偿导频信号的所述相位补偿OFDM符号，以便于接入点确定频率偏差估计值。
  2. 根据权利要求1所述的方法，其特征在于，所述生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k个子载波上均承载所述站点的所述相位补偿导频信号，其中k0≤k≤N-1，k0为子载波的起始位置。
  3. 根据权利要求1所述的方法，其特征在于，所述生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述导频信号满足公式(1)，其中，pm(k)表示所述站点在第k个子载波上的所述导频信号，p0为常数，k表示所述OFDM符号的子载波的序号，Δm表示所述站点的相位偏移系数；
    所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k个子载波上承载所述站点的所述相位补偿导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，k0为子载波的起始位置，x取整数，mod(a，b)表示a/b取余数。
  4. 根据权利要求1所述的方法，其特征在于，所述生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，所述第k个子载波在第l组子载波中，所述第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k子载波上均承载所述站点的所述相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
  5. 根据权利要求1所述的方法，其特征在于，所述生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述导频信号满足公式(1)，其中，pm(k)表示所述站点在第k个子载波上的所述导频信号，p0为常数，k表示所述OFDM符号的子载波的序号，Δm表示所述站点的相位偏移系数；
    所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，所述第k个子载波在第l组子载波中，所述第 l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k个子载波上承载所述站点的所述相位补偿导频信号，其中，所述第k个子载波在第l组子载波中，所述第l组子载波包括L个子载波，L为大于或等于2的整数，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，1≤z≤M，z取整数，l取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
  6. 一种无线局域网中处理信号的方法，其特征在于，包括：
    确定站点发送数据信号所经过的信道的信道响应信息；
    根据所述信道响应信息，确定所述站点的频率偏差估计值；
    接收所述站点在所述信道发送的所述数据信号；
    根据所述信道响应信息和所述频率偏差估计值，解析所述数据信号。
  7. 根据权利要求6所述的方法，其特征在于，所述方法还包括：
    确定所述站点发送相位补偿导频信号所经过的信道的相位补偿信道响应信息；
    所述根据所述信道响应信息，确定所述站点的频率偏差估计值，包括：
    根据所述信道响应信息和所述相位补偿信道响应信息，确定所述站点的所述频率偏差估计值。
  8. 根据权利要求7所述的方法，其特征在于，所述方法还包括：
    确定所述站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，所述M为站点所在分组的站点的个数；
    所述确定站点发送数据信号所经过的信道的信道响应信息，包括：
    根据所述M个OFDM符号中的第i个OFDM符号，将所述站点发送所述第i个OFDM符号中的导频信号所经过的信道的信道响应信息确定为第i个信道响应信息，i取正整数，1≤i≤M；
    所述确定所述站点发送相位补偿导频信号所经过的信道的相位补偿信 道响应信息，包括：
    根据所述相位补偿OFDM符号，确定所述站点发送所述相位补偿OFDM符号中的相位补偿导频信号所经过的信道的所述相位补偿信道响应信息；
    所述根据所述信道响应信息和所述相位补偿信道响应信息，确定所述站点的所述频率偏差估计值，包括：
    根据所述站点的所述第i个信道响应信息和所述相位补偿信道响应信息，确定所述站点的所述频率偏差估计值。
  9. 根据权利要求8所述的方法，其特征在于，所述根据所述站点的所述第i个信道响应信息和所述相位补偿信道响应信息，确定所述站点的所述频率偏差估计值，包括：
    根据所述站点的M个信道响应信息和所述相位补偿信道响应信息，确定所述站点的M个频率偏差估计值；
    确定所述站点的所述M个频率偏差估计值的平均值为所述站点的所述频率偏差估计值。
  10. 根据权利要求8或9所述的方法，其特征在于，所述确定所述站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载所述站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k子载波上均承载所述站点的所述相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
  11. 根据权利要求8或9所述的方法，其特征在于，所述确定所述站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载所述站点的导频信号，其中， k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k个子载波上承载所述站点的所述相位补偿导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，x取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
  12. 根据权利要求8或9所述的方法，其特征在于，所述确定所述站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载所述站点的导频信号，其中，所述第k个子载波在第l组子载波中，所述第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k子载波上均承载所述站点的所述相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
  13. 根据权利要求8或9所述的方法，其特征在于，所述确定所述站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载所述站点的导频信号，其中，所述第k个子载波在第l组子载波中，所述第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k个子载波上承载所述站点的所述相位补偿导频信号，其中，所述第k个子载波在第l组子载波中，所述第l组子载波包括L个子载波，L为大于或等于2的整数，k＝mod(k0+(m-1)L+lML+(z-1)L+x,N)，1≤z≤M，z取整数，0≤x<L，x取整数，0≤l≤N/(L*M)，l取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
  14. 根据权利要求10至13中任一项所述的方法，其特征在于，所述确定所述站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：
    确定所述相位补偿OFDM符号，所述站点的所述相位补偿OFDM符号中的所述相位补偿导频信号满足公式(1)：
    Figure PCTCN2014091160-appb-100002
    其中，pm(k)表示所述站点在第k个子载波上的所述相位补偿导频信号，p0为常数，k表示所述相位补偿OFDM符号的子载波的序号，Δm表示所述站点的相位偏移系数。
  15. 根据权利要求11或13所述的方法，其特征在于，所述确定所述站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，包括：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述导频信号满足公式(1)，其中，pm(k)表示所述站点在第k个子载波上的所述导频信号，p0为常数，k表示所述OFDM符号的子载波的序号，Δm表示所述站点的相位偏移系数。
  16. 根据权利要求7至15中任一项所述的方法，其特征在于，所述根据所述信道响应信息和所述相位补偿信道响应信息，确定所述站点的所述频率偏差估计值，包括：
    根据下面的公式(2)确定所述站点的所述频率偏差估计值：
    Figure PCTCN2014091160-appb-100003
    其中，δFm,i表示所述站点的第i个频率偏差估计值，m表示所述站点的序号，1≤m≤M，CP表示所述第i个OFDM符号的保护间隔长度，N表示所述第i个OFDM符号中的子载波的个数，k表示所述站点在第i个OFDM 符号中占用的所述子载波的序号，k0≤k≤N-1，k∈Kim表示k分别取所述站点在所述第i个OFDM符号中占用的所述子载波的序号，mean{}表示求平均值，angle()表示求相位，Hm,i(k)表示所述站点的第i个信道响应信息，Hm,M+1(k)表示所述站点的所述相位补偿信道响应信息，
    Figure PCTCN2014091160-appb-100004
    表示Hm,M+1(k)的共轭。
  17. 根据权利要求8至16中任一项所述的方法，其特征在于，所述根据所述M个OFDM符号中的第i个OFDM符号，将所述站点发送所述第i个OFDM符号中的导频信号所经过的信道的信道响应信息确定为第i个信道响应信息，包括：
    确定所述站点发送的所述M个OFDM符号中的第i个OFDM符号中的接收导频信号；
    根据第i个预设导频信号和所述第i个OFDM符号中的接收导频信号确定所述站点的所述第i个信道响应信息；
    所述根据所述相位补偿OFDM符号，确定所述站点发送所述相位补偿OFDM符号中的相位补偿导频信号所经过的信道的所述相位补偿信道响应信息，包括：
    确定所述站点发送的所述相位补偿OFDM符号中的所述相位补偿导频信号；
    根据预设相位补偿导频信号和所述相位补偿导频信号，确定所述站点的所述相位补偿信道响应信息。
  18. 根据权利要求17所述的方法，其特征在于，所述确定所述站点发送的所述相位补偿OFDM符号中的所述相位补偿导频信号，包括：
    接收多个站点发送的相位补偿OFDM符号中的导频信号；
    将所述导频信号进行逆傅里叶变换IDFT，确定第一导频信号；
    将所述第一导频信号进行滤波处理，确定第二导频信号；
    将所述第二导频信号进行傅里叶变换DFT，确定第三导频信号；
    根据所述第三导频信号，确定所述站点发送的所述相位补偿OFDM符号中的所述相位补偿导频信号。
  19. 一种站点无线局域网中的站点，其特征在于，包括：
    生成模块，用于生成用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，所述M为站点所在分组的 站点的个数，所述相位补偿OFDM符号中的所述相位补偿导频信号满足下面的公式(1)：
    Figure PCTCN2014091160-appb-100005
    其中，pm(k)表示所述站点在第k个子载波上的所述相位补偿导频信号，p0为常数，k表示所述相位补偿OFDM符号的子载波的序号，Δm表示所述站点的相位偏移系数；
    发送模块，用于向接入点发送包括所述导频信号的所述M个OFDM符号，和，包括所述相位补偿导频信号的所述相位补偿OFDM符号，以便于接入点确定频率偏差估计值。
  20. 根据权利要求19所述的站点，其特征在于，所述生成模块具体用于：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k子载波上均承载所述站点的所述相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
  21. 根据权利要求19所述的站点，其特征在于，所述生成模块具体用于：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述导频信号满足公式(1)，其中，pm(k)表示所述站点在第k个子载波上的所述导频信号，p0为常数，k表示所述OFDM符号的子载波的序号，Δm表示所述站点的相位偏移系数；
    所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k个子载波上承载所述站点的所述相位补偿导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，x取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
  22. 根据权利要求19所述的站点，其特征在于，所述生成模块具体用于：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，所述第k个子载波在第l组子载波中，所述第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k子载波上均承载所述站点的所述相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
  23. 根据权利要求19所述的站点，其特征在于，所述生成模块具体用于：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述导频信号满足公式(1)，其中，pm(k)表示所述站点在第k个子载波上的所述导频信号，p0为常数，k表示所述OFDM符号的子载波的序号，Δm表示所述站点的相位偏移系数；
    所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载站点的导频信号，其中，所述第k个子载波在第l组子载波中，所述第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k个子载波上承载所述站点的所述相位补偿导频信号，其中，所述第k个子载波 在第l组子载波中，所述第l组子载波包括L个子载波，L为大于或等于2的整数，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，，0≤x<L，x取整数，0≤l≤N/(L*M)，l取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
  24. 一种无线局域网中的接入点，其特征在于，包括：
    第一确定模块，用于确定站点发送数据信号所经过的信道的信道响应信息；
    第二确定模块，用于根据所述信道响应信息，确定所述站点的频率偏差估计值；
    接收模块，用于接收所述站点在所述信道发送的所述数据信号；
    处理模块，用于根据所述信道响应信息和所述频率偏差估计值，解析所述数据信号。
  25. 根据权利要求24所述的接入点，其特征在于，所述第一确定模块还用于：
    确定所述站点发送相位补偿导频信号所经过的信道的相位补偿信道响应信息；
    所述第二确定模块具体用于：
    根据所述信道响应信息和所述相位补偿信道响应信息，确定所述站点的所述频率偏差估计值。
  26. 根据权利要求25所述的接入点，其特征在于，所述第一确定模块具体用于：
    确定所述站点用于发送导频信号的M个OFDM符号，和，用于发送相位补偿导频信号的相位补偿OFDM符号，所述M为站点所在分组的站点的个数；
    根据所述M个OFDM符号中的第i个OFDM符号，将所述站点发送所述第i个OFDM符号中的导频信号所经过的信道的信道响应信息确定为第i个信道响应信息，i取正整数，1≤i≤M；
    根据所述相位补偿OFDM符号，确定所述站点发送所述相位补偿OFDM符号中的相位补偿导频信号所经过的信道的所述相位补偿信道响应信息；
    所述第二确定模块具体用于：
    根据所述站点的所述第i个信道响应信息和所述相位补偿信道响应信 息，确定所述站点的所述频率偏差估计值。
  27. 根据权利要求26所述的接入点，其特征在于，所述第二确定模块具体用于：
    根据所述站点的M个信道响应信息和所述相位补偿信道响应信息，确定所述站点的M个频率偏差估计值；
    确定所述站点的所述M个频率偏差估计值的平均值为所述站点的所述频率偏差估计值。
  28. 根据权利要求26或27所述的接入点，其特征在于，所述第一确定模块具体用于：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载所述站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k子载波上均承载所述站点的所述相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
  29. 根据权利要求26或27所述的接入点，其特征在于，所述第一确定模块具体用于：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载所述站点的导频信号，其中，k＝mod(k0+m-1+xM+i-1,N)，0≤x≤N/M，x取整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k个子载波上承载所述站点的所述相位补偿导频信号，其中，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x≤N/M，x取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
  30. 根据权利要求26或27所述的接入点，其特征在于，所述第一确定 模块具体用于：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载所述站点的导频信号，其中，所述第k个子载波在第l组子载波中，所述第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k子载波上均承载所述站点的所述相位补偿导频信号，其中，k0≤k≤N-1，k0为子载波的起始位置。
  31. 根据权利要求26或27所述的接入点，其特征在于，所述第一确定模块具体用于：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述第i个OFDM符号中的第k个子载波上承载所述站点的导频信号，其中，所述第k个子载波在第l组子载波中，所述第l组子载波包括L个子载波，k＝mod(k0+(m-1)L+lML+(i-1)L+x,N)，0≤x<L，x取整数，0≤l≤N/(L*M)，L为大于或等于2的整数，m表示所述站点的序号，1≤m≤M，k0≤k≤N-1，N表示所述第m个OFDM符号中的子载波的个数，l、m、k和N取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数；
    确定所述相位补偿OFDM符号，所述相位补偿OFDM符号中的第k个子载波上承载所述站点的所述相位补偿导频信号，其中，所述第k个子载波在第l组子载波中，所述第l组子载波包括L个子载波，L为大于或等于2的整数，k＝mod(k0+m-1+xM+z-1,N)，1≤z≤M，z取整数，0≤x<L，x取整数，0≤l≤N/(L*M)，l取整数，k0为子载波的起始位置，mod(a，b)表示a/b取余数。
  32. 根据权利要求18至31中任一项所述的接入点，其特征在于，所述第一确定模块具体用于：
    确定所述相位补偿OFDM符号，所述站点的所述相位补偿OFDM符号中的所述相位补偿导频信号满足公式(1)：
    Figure PCTCN2014091160-appb-100006
    其中，pm(k)表示所述站点在第k个子载波上的所述相位补偿导频信号，p0为常数，k表示所述相位补偿OFDM符号的子载波的序号，Δm表示所述站点的相位偏移系数。
  33. 根据权利要求29或31所述的方法，其特征在于，所述第一确定模块具体用于：
    确定所述M个OFDM符号，所述M个OFDM符号中的所述导频信号满足公式(1)，其中，pm(k)表示所述站点在第k个子载波上的所述导频信号，p0为常数，k表示所述OFDM符号的子载波的序号，Δm表示所述站点的相位偏移系数。
  34. 根据权利要求25至33中任一项所述的接入点，其特征在于，所述第二确定模块具体用于：
    根据下面的公式(2)确定所述站点的所述频率偏差估计值：
    Figure PCTCN2014091160-appb-100007
    其中，δFm,i表示所述站点的第i个频率偏差估计值，m表示所述站点的序号，1≤m≤M，CP表示所述第i个OFDM符号的保护间隔长度，N表示所述第i个OFDM符号中的子载波的个数，k表示所述站点在第i个OFDM符号中占用的所述子载波的序号，k0≤k≤N-1，k∈Kim表示k分别取所述站点在所述第i个OFDM符号中占用的所述子载波的序号，mean{}表示求平均值，angle()表示求相位，Hm,i(k)表示所述站点的第i个信道响应信息，Hm,M+1(k)表示所述站点的所述相位补偿信道响应信息，
    Figure PCTCN2014091160-appb-100008
    表示Hm,M+1(k)的共轭。
  35. 根据权利要求26至34中任一项所述的接入点，其特征在于，所述第一确定模块具体用于：
    确定所述站点发送的所述M个OFDM符号中的第i个OFDM符号中的接收导频信号；
    根据第i个预设导频信号和所述第i个OFDM符号中的接收导频信号确定所述站点的所述第i个信道响应信息；
    确定所述站点发送的所述相位补偿OFDM符号中的所述相位补偿导频信号；
    根据预设相位补偿导频信号和所述相位补偿导频信号，确定所述站点的 所述相位补偿信道响应信息。
  36. 根据权利要求35所述的接入点，其特征在于，所述第一确定模块具体用于：
    接收多个站点发送的相位补偿OFDM符号中的导频信号；
    将所述导频信号进行逆傅里叶变换IDFT，确定第一导频信号；
    将所述第一导频信号进行滤波处理，确定第二导频信号；
    将所述第二导频信号进行傅里叶变换DFT，确定第三导频信号；
    根据所述第三导频信号，确定所述站点发送的所述相位补偿OFDM符号中的所述相位补偿导频信号。
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103139128A (zh) * 2011-12-05 2013-06-05 中国科学院微电子研究所 一种ofdm系统相位补偿的方法
CN103873416A (zh) * 2014-03-12 2014-06-18 南京软仪测试技术有限公司 一种evm相位估计与补偿方法
WO2014128019A1 (en) * 2013-02-22 2014-08-28 St-Ericsson Sa Estimation of the cfo by transmission of a single subcarrier signal in ofdm system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103139128A (zh) * 2011-12-05 2013-06-05 中国科学院微电子研究所 一种ofdm系统相位补偿的方法
WO2014128019A1 (en) * 2013-02-22 2014-08-28 St-Ericsson Sa Estimation of the cfo by transmission of a single subcarrier signal in ofdm system
CN103873416A (zh) * 2014-03-12 2014-06-18 南京软仪测试技术有限公司 一种evm相位估计与补偿方法

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