阅读说明：本技术 解析wlan信号的方法、接收机、设备及存储介质 (Method, receiver, device and storage medium for analyzing WLAN signal ) 是由 汤志刚 朱安国 于 2021-07-22 设计创作，主要内容包括：本发明提供了一种解析WLAN信号的方法、接收机、设备及存储介质,该方法包括：对WLAN信号按照第一频带进行第一次频谱搬移,对WLAN信号按照第一频带进行滤波之后粗同步；在完成粗同步后,对WLAN信号按照第二频带进行第二次频谱搬移,对WLAN信号按照第二频带进行滤波之后傅里叶变换,得到频域数据；从频域数据中选取第一频带的子载波进行解调,确定WLAN信号的信号带宽、帧格式、空时流数及扩展的空间流数；对WLAN信号按照信号带宽进行第三次频谱搬移并按信号带宽进行滤波；根据信号带宽、帧格式、空时流数及扩展的空间流数,对第三次频谱搬移后的WLAN信号进行信道估计和均衡解调。本发明能实现WLAN信号的实时盲解,无需缓存时域数据,从而减少存储空间和降低处理延时。(The invention provides a method, a receiver, equipment and a storage medium for analyzing WLAN signals, wherein the method comprises the following steps: carrying out first frequency spectrum shifting on the WLAN signal according to a first frequency band, and carrying out coarse synchronization after filtering the WLAN signal according to the first frequency band; after coarse synchronization is finished, carrying out secondary spectrum shifting on the WLAN signal according to a second frequency band, filtering the WLAN signal according to the second frequency band, and carrying out Fourier transform to obtain frequency domain data; selecting a subcarrier of a first frequency band from the frequency domain data for demodulation, and determining the signal bandwidth, the frame format, the number of space-time streams and the number of expanded spatial streams of the WLAN signal; carrying out third-time spectrum shifting on the WLAN signal according to the signal bandwidth and filtering according to the signal bandwidth; and performing channel estimation and equalization demodulation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the frame format, the number of space-time streams and the number of expanded space streams. The invention can realize the real-time blind solution of the WLAN signal without buffering time domain data, thereby reducing the storage space and reducing the processing time delay.)

1. A method of resolving WLAN signals, comprising:

carrying out first frequency spectrum shifting on the received WLAN signal according to a first frequency band, and carrying out coarse synchronization after filtering the WLAN signal subjected to the first frequency spectrum shifting according to the first frequency band;

after coarse synchronization is finished, carrying out secondary spectrum shifting on the WLAN signal according to a second frequency band, filtering the WLAN signal subjected to the secondary spectrum shifting according to the second frequency band, and carrying out Fourier transform to obtain frequency domain data;

selecting a subcarrier corresponding to the first frequency band from the frequency domain data for demodulation, and determining the signal bandwidth, the frame format, the number of space-time streams and the number of expanded spatial streams of the WLAN signal;

carrying out third-time spectrum shifting on the WLAN signal according to the signal bandwidth, and filtering according to the signal bandwidth;

and performing channel estimation and equalization demodulation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the frame format, the number of space-time streams and the number of expanded space streams.

2. The method according to claim 1, wherein the performing the first spectrum shifting on the received WLAN signal according to the first frequency band, and performing the coarse synchronization after filtering the WLAN signal after the first spectrum shifting according to the first frequency band, comprises:

carrying out first spectrum shifting on the WLAN signal according to a first frequency band according to a preset working channel and working bandwidth;

switching the filter to a first frequency band and filtering the WLAN signal after the first time of spectrum shifting;

and carrying out coarse synchronization on the filtered WLAN signal.

3. The method according to claim 1, wherein the performing a second spectrum shift on the WLAN signal according to a second frequency band, and performing a fourier transform on the WLAN signal after the second spectrum shift after filtering according to the second frequency band to obtain frequency domain data comprises:

carrying out second spectrum shifting on the WLAN signal according to a second frequency band according to a preset working channel and working bandwidth;

switching the filter to a second frequency band and filtering the WLAN signal after the second time of frequency spectrum shifting;

and carrying out Fourier transform on the filtered WLAN signal to obtain frequency domain data.

4. The method of parsing a WLAN signal of claim 1 wherein said selecting a subcarrier corresponding to said first frequency band from said frequency domain data for demodulation to determine a signal bandwidth, a frame format, a number of space-time streams, and a number of spread spatial streams of said WLAN signal comprises:

extracting a subcarrier corresponding to the first frequency band from the frequency domain data;

demodulating the subcarrier to obtain a signaling domain of the WLAN signal;

and determining the signal bandwidth, the frame format, the number of space-time streams and the number of extended spatial streams of the WLAN signal according to the signaling domain.

5. The method of claim 1, wherein the third spectral shifting and filtering of the WLAN signal according to the signal bandwidth comprises:

carrying out third time spectrum shifting on the WLAN signal according to the signal bandwidth;

and switching the filter to the signal bandwidth and filtering the WLAN signal after the third time of spectrum shifting.

6. The method of resolving a WLAN signal as claimed in claim 4, wherein said performing channel estimation and equalization demodulation on the third time spectrum shifted WLAN signal according to the signal bandwidth, the frame format, the number of space-time streams and the number of spread spatial streams comprises:

performing channel estimation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the number of space-time streams and the number of expanded space streams;

and performing equalization demodulation on the data domain of the WLAN signal according to the channel estimation result, the signal bandwidth and the frame format.

7. The method of resolving WLAN signals of claim 4 wherein said determining a signal bandwidth, a frame format, a number of space-time streams, and a number of extended spatial streams of said WLAN signals from said signaling domain comprises:

after the WLAN signal is coarsely synchronized, judging whether the modulation mode of the 5 th time domain symbol of the WLAN signal is BPSK;

if not, the frame format of the WLAN signal is an HT-GF frame format;

if yes, judging whether the modulation mode of the 6 th time domain symbol of the WLAN signal is BPSK;

if not, the frame format of the WLAN signal is an HT-MF frame format;

if yes, judging whether the modulation mode of the 7 th time domain symbol of the WLAN signal is QBPSK;

if so, the frame format of the WLAN signal is a VHT frame format;

if not, the frame format of the WLAN signal is a NonHT frame format;

and determining the signal bandwidth, the number of space-time streams and the number of extended spatial streams of the WLAN signal according to the determined frame format of the WLAN signal.

8. The method of parsing a WLAN signal of claim 7 wherein determining a signal bandwidth, a number of space-time streams, and a number of extended spatial streams of the WLAN signal based on the determined frame format of the WLAN signal comprises:

judging whether the frame format of the WLAN signal is a NonHT frame format or not;

if so, the signal bandwidth of the WLAN signal is 20M, the corresponding number of space-time streams is 1, and the corresponding number of extended space streams is 0;

if not, judging whether the frame format of the WLAN signal is an HT-MF frame format or an HT-GF frame format;

if yes, analyzing corresponding signal bandwidth, space-time stream number and expanded space stream number from the HT-SIG domain of the WLAN signal;

if not, judging that the frame format of the WLAN signal is a VHT frame format, analyzing corresponding signal bandwidth and space-time stream number from a VHT-SIG-A domain of the WLAN signal, and determining that the number of the expanded space streams of the WLAN signal is 0.

9. A receiver for resolving WLAN signals, comprising:

the first signal processing module is used for carrying out first frequency spectrum shifting on the received WLAN signal according to a first frequency band, and carrying out coarse synchronization after filtering the WLAN signal subjected to the first frequency spectrum shifting according to the first frequency band;

the second signal processing module is used for carrying out second frequency spectrum shifting on the WLAN signal according to a second frequency band after coarse synchronization is finished, filtering the WLAN signal subjected to the second frequency spectrum shifting according to the second frequency band, and carrying out Fourier transform to obtain frequency domain data;

a first demodulation module, configured to select a subcarrier corresponding to the first frequency band from the frequency domain data for demodulation, and determine a signal bandwidth, a frame format, a number of space-time streams, and a number of extended spatial streams of the WLAN signal;

the third signal processing module is used for carrying out third time spectrum shifting on the WLAN signal according to the signal bandwidth and filtering according to the signal bandwidth;

and the second demodulation module is used for performing channel estimation and equalization demodulation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the frame format, the number of space-time streams and the number of expanded spatial streams.

10. An apparatus for resolving WLAN signals, characterized by a processor and a communication module; wherein the communication module is coupled to the processor, the processor being configured to run a computer program to implement the method of resolving WLAN signals according to any one of claims 1 to 8, the communication module being configured to communicate with a module other than the apparatus for resolving WLAN signals.

11. A computer-readable storage medium, comprising a stored computer program, wherein the computer program, when executed, controls an apparatus in which the computer-readable storage medium is located to perform the method for resolving WLAN signals according to any one of claims 1 to 8.

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method, a receiver, a device, and a storage medium for analyzing a WLAN signal.

Background

Several frame formats specified by the WLAN protocol are shown in fig. 1, where frames of the WLAN protocol are composed of a preamble and a data field, where a short training field (xx-STF) of the preamble is generally used for synchronization and AGC adjustment, a long training field (xx-LTF) is generally used for channel estimation, a signaling field (xx-SIG) generally contains some basic configuration information of the frame, and the data field contains data to be transmitted. The HT-LTF1 of the preamble portion in the HT-GF frame format may be used for channel estimation in the preamble signaling field, and the second symbol thereof may also be used for channel estimation in the data field. However, since the signal bandwidth is to be resolved in the signaling domain, when the signal bandwidth is unknown, it may be necessary to buffer the second symbol time domain data of HT-LTF1, and perform channel estimation of the corresponding bandwidth after determining the bandwidth, thereby increasing the storage space of the WLAN receiver and increasing the processing delay.

Disclosure of Invention

In view of the foregoing problems, an object of the present invention is to provide a method, a receiver, a device, and a storage medium for analyzing a WLAN signal, which can implement a real-time blind solution of the WLAN signal without buffering time domain data, thereby reducing a storage space and reducing a processing delay.

In a first aspect, an embodiment of the present invention provides a method for analyzing a WLAN signal, including:

carrying out first frequency spectrum shifting on the received WLAN signal according to a first frequency band, and carrying out coarse synchronization after filtering the WLAN signal subjected to the first frequency spectrum shifting according to the first frequency band;

after coarse synchronization is finished, carrying out secondary spectrum shifting on the WLAN signal according to a second frequency band, filtering the WLAN signal subjected to the secondary spectrum shifting according to the second frequency band, and carrying out Fourier transform to obtain frequency domain data;

selecting a subcarrier corresponding to the first frequency band from the frequency domain data for demodulation, and determining the signal bandwidth, the frame format, the number of space-time streams and the number of expanded spatial streams of the WLAN signal;

carrying out third-time spectrum shifting on the WLAN signal according to the signal bandwidth, and filtering according to the signal bandwidth;

and performing channel estimation and equalization demodulation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the frame format, the number of space-time streams and the number of expanded space streams.

As an improvement of the above scheme, the performing a first spectrum shift on the received WLAN signal according to a first frequency band, and performing coarse synchronization after filtering the WLAN signal after the first spectrum shift according to the first frequency band includes:

carrying out first spectrum shifting on the WLAN signal according to a first frequency band according to a preset working channel and working bandwidth;

switching the filter to a first frequency band and filtering the WLAN signal after the first time of spectrum shifting;

and carrying out coarse synchronization on the filtered WLAN signal.

As an improvement of the above scheme, the performing a second spectrum shift on the WLAN signal according to a second frequency band, and performing fourier transform on the WLAN signal after the second spectrum shift after filtering according to the second frequency band to obtain frequency domain data includes:

carrying out second spectrum shifting on the WLAN signal according to a second frequency band according to a preset working channel and working bandwidth;

switching the filter to a second frequency band and filtering the WLAN signal after the second time of frequency spectrum shifting;

and carrying out Fourier transform on the filtered WLAN signal to obtain frequency domain data.

As an improvement of the above scheme, the selecting a subcarrier corresponding to the first frequency band from the frequency domain data for demodulation, and determining a signal bandwidth, a frame format, a number of space-time streams, and a number of extended spatial streams of the WLAN signal include:

extracting a subcarrier corresponding to the first frequency band from the frequency domain data;

demodulating the subcarrier to obtain a signaling domain of the WLAN signal;

and determining the signal bandwidth, the frame format, the number of space-time streams and the number of extended spatial streams of the WLAN signal according to the signaling domain.

As an improvement of the above scheme, the performing a third time of spectrum shifting on the WLAN signal according to the signal bandwidth and filtering according to the signal bandwidth includes:

carrying out third time spectrum shifting on the WLAN signal according to the signal bandwidth;

and switching the filter to the signal bandwidth and filtering the WLAN signal after the third time of spectrum shifting.

As an improvement of the above scheme, the performing channel estimation and equalization demodulation on the WLAN signal after the third time of spectrum shift according to the signal bandwidth, the frame format, the number of space-time streams, and the number of spread spatial streams includes:

performing channel estimation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the number of space-time streams and the number of expanded space streams;

and performing equalization demodulation on the data domain of the WLAN signal according to the channel estimation result, the signal bandwidth and the frame format.

As an improvement of the above scheme, the determining, according to the signaling domain, a signal bandwidth, a frame format, a number of space-time streams, and a number of extended spatial streams of the WLAN signal includes:

after the WLAN signal is coarsely synchronized, judging whether the modulation mode of the 5 th time domain symbol of the WLAN signal is BPSK;

if not, the frame format of the WLAN signal is an HT-GF frame format;

if yes, judging whether the modulation mode of the 6 th time domain symbol of the WLAN signal is BPSK;

if not, the frame format of the WLAN signal is an HT-MF frame format;

if yes, judging whether the modulation mode of the 7 th time domain symbol of the WLAN signal is QBPSK;

if so, the frame format of the WLAN signal is a VHT frame format;

if not, the frame format of the WLAN signal is a NonHT frame format;

and determining the signal bandwidth, the number of space-time streams and the number of extended spatial streams of the WLAN signal according to the determined frame format of the WLAN signal.

As an improvement of the above solution, the determining the signal bandwidth, the number of space-time streams and the number of extended spatial streams of the WLAN signal according to the determined frame format of the WLAN signal includes:

judging whether the frame format of the WLAN signal is a NonHT frame format or not;

if so, the signal bandwidth of the WLAN signal is 20M, the corresponding number of space-time streams is 1, and the corresponding number of extended space streams is 0;

if not, judging whether the frame format of the WLAN signal is an HT-MF frame format or an HT-GF frame format;

if yes, analyzing corresponding signal bandwidth, space-time stream number and expanded space stream number from the HT-SIG domain of the WLAN signal;

if not, judging that the frame format of the WLAN signal is a VHT frame format, analyzing corresponding signal bandwidth and space-time stream number from a VHT-SIG-A domain of the WLAN signal, and determining that the number of the expanded space streams of the WLAN signal is 0.

In a second aspect, an embodiment of the present invention provides a receiver for resolving a WLAN signal, including:

the first signal processing module is used for carrying out first frequency spectrum shifting on the received WLAN signal according to a first frequency band, and carrying out coarse synchronization after filtering the WLAN signal subjected to the first frequency spectrum shifting according to the first frequency band;

the second signal processing module is used for carrying out second frequency spectrum shifting on the WLAN signal according to a second frequency band after coarse synchronization is finished, filtering the WLAN signal subjected to the second frequency spectrum shifting according to the second frequency band, and carrying out Fourier transform to obtain frequency domain data;

a first demodulation module, configured to select a subcarrier corresponding to the first frequency band from the frequency domain data for demodulation, and determine a signal bandwidth, a frame format, a number of space-time streams, and a number of extended spatial streams of the WLAN signal;

the third signal processing module is used for carrying out third time spectrum shifting on the WLAN signal according to the signal bandwidth and filtering according to the signal bandwidth;

and the second demodulation module is used for performing channel estimation and equalization demodulation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the frame format, the number of space-time streams and the number of expanded spatial streams.

In a third aspect, an embodiment of the present invention provides an apparatus for analyzing a WLAN signal, a processor, and a communication module; wherein the communication module is coupled to the processor, the processor is configured to run a computer program to implement the method for resolving a WLAN signal according to any one of the first aspect, and the communication module is configured to communicate with a module other than a device for resolving a WLAN signal.

In a fourth aspect, the present invention provides a computer-readable storage medium, where the computer-readable storage medium includes a stored computer program, where the computer program, when running, controls an apparatus where the computer-readable storage medium is located to perform the method for resolving a WLAN signal according to any one of the first aspect.

Compared with the prior art, the embodiment of the invention has the beneficial effects that: the method for analyzing the WLAN signal comprises the following steps: carrying out first frequency spectrum shifting on the received WLAN signal according to a first frequency band, and carrying out coarse synchronization after filtering the WLAN signal subjected to the first frequency spectrum shifting according to the first frequency band; after coarse synchronization is finished, carrying out secondary spectrum shifting on the WLAN signal according to a second frequency band, filtering the WLAN signal subjected to the secondary spectrum shifting according to the second frequency band, and carrying out Fourier transform to obtain frequency domain data; selecting a subcarrier corresponding to the first frequency band from the frequency domain data for demodulation, and determining the signal bandwidth, the frame format, the number of space-time streams and the number of expanded spatial streams of the WLAN signal; carrying out third-time spectrum shifting on the WLAN signal according to the signal bandwidth, and filtering according to the signal bandwidth; and performing channel estimation and equalization demodulation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the frame format, the number of space-time streams and the number of expanded space streams. The invention can realize the real-time blind solution of the WLAN signal without buffering time domain data, thereby reducing the storage space and reducing the processing time delay.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a diagram of a frame format specified by the WLAN protocol;

fig. 2 is a flowchart of a method for analyzing WLAN signals according to a first embodiment of the present invention;

FIG. 3 is a diagram illustrating a 20M spectrum shift according to an embodiment of the present invention;

fig. 4 is a schematic overall flow chart of WLAN signal analysis according to an embodiment of the present invention;

fig. 5 is a schematic diagram of an apparatus for analyzing WLAN signals according to a second embodiment of the present invention;

fig. 6 is a schematic diagram of an apparatus for analyzing a WLAN signal according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

Referring to fig. 2, a method for analyzing a WLAN signal according to an embodiment of the present invention is executed by a WLAN receiver, and specifically includes:

s1: carrying out first frequency spectrum shifting on the received WLAN signal according to a first frequency band, and carrying out coarse synchronization after filtering the WLAN signal subjected to the first frequency spectrum shifting according to the first frequency band;

s2: after coarse synchronization is finished, carrying out secondary spectrum shifting on the WLAN signal according to a second frequency band, filtering the WLAN signal subjected to the secondary spectrum shifting according to the second frequency band, and carrying out Fourier transform to obtain frequency domain data;

illustratively, the first frequency band is 20M and the second frequency band is 40M. Since the preamble is generally copied from 20M frequency domain data, that is, the 20M frequency domain data already contains the basic information of the frame of the WLAN protocol, and in the HT-GF frame format, one symbol of the HT-LTF1 is used in channel estimation and equalization of the data domain, and all the information of 20M in the xx-LTF can be obtained in the 40M frequency domain data, in order to be compatible with the 40M bandwidth, the received signal is shifted by 20M in frequency spectrum under the condition of not determining the channel bandwidth, as shown in fig. 3. And then, performing coarse synchronization after filtering the signal by a 20M filter, wherein the purpose of the coarse synchronization is to determine whether the signal is a WLAN signal, and based on the xx-STF period being 0.8us, the xx-STF autocorrelation exceeds a threshold value, and the received signal is considered as the WLAN signal. After coarse synchronization, the spectrum is shifted and then filtered with a 40M filter. And then performing FFT on the WLAN signal after the frequency spectrum shifting to obtain frequency domain data of 128 points.

S3: selecting a subcarrier corresponding to the first frequency band from the frequency domain data for demodulation, and determining the signal bandwidth, the frame format, the number of space-time streams and the number of expanded spatial streams of the WLAN signal;

for example, the signal bandwidth, the frame format, the number of space-time streams, and the number of extended spatial streams of the WLAN signal may be determined according to the modulation scheme and content of the signal field. In a frame of a WLAN protocol, a signaling domain L-SIG, an HT-SIG and a VHT-SIG-A are obtained by copying basic signals of a 20M frequency domain, and a signaling domain VHT-SIG-B is obtained by copying bits, so that when some basic information of a data frame needs to be obtained, only signals with 20M bandwidth need to be obtained and analyzed. Meanwhile, xx-STF is also copied from 20M frequency domain data, and similarly, some basic information of the data frame can be obtained through the 20M bandwidth signal. The signaling domain carries at least one of the following information: first indication information, for example, 20M, 40M, etc., for indicating a bandwidth employed for transmitting the data field; second indication information for indicating a modulation technique employed by the data field, e.g., BPSK, QPSK, etc.; third indication information indicating a modulation technique of the data domain, for example, the number of spread spatial streams and/or space-time streams. Therefore, when the signaling domain is decoded, the subcarrier corresponding to the 20M frequency domain may be selected to demodulate, so as to obtain the modulation technique and content carried by the signaling domain (xx-SIG), and further, the frame format, the bandwidth, the number of space-time streams, and the number of extended space streams of the received WLAN signal may be determined.

Illustratively, the signal bandwidth is determined as follows: 11a is determined by the frame format (only 20M), 11n gets the bandwidth by decoding HT-SIG, and 11ac gets the bandwidth by decoding VHT-SIG-A.

S4: carrying out third-time spectrum shifting on the WLAN signal according to the signal bandwidth, and filtering according to the signal bandwidth;

after the signal bandwidth is determined, the WLAN signal carries out spectrum shifting according to the determined signal bandwidth, and the signal with the corresponding bandwidth can be shifted to the central frequency point of the working bandwidth.

S5: and performing channel estimation and equalization demodulation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the frame format, the number of space-time streams and the number of expanded space streams.

For the 802.11 series protocol standard of WLAN, channel estimation and equalization demodulation of the data domain of the WLAN signal can be performed based on the frame format (e.g., 11a, 11n, 11ac), the signal bandwidth, the number of space-time streams, and the number of extended space streams, so as to recover the transmission signal corresponding to the WLAN signal. After the frequency spectrum shifting of 20M and 40M, the invention demodulates the subcarrier of 20M frequency domain, determines the signal bandwidth, frame format, space-time stream number and expanded space stream number, and shifts the signal to the central frequency point of the working bandwidth according to the working bandwidth, thereby realizing the real-time blind solution of the WLAN signal, without buffering the time domain data, reducing the storage space and the processing delay.

In an optional embodiment, the performing a first spectrum shift on the received WLAN signal according to a first frequency band, and performing coarse synchronization after filtering the WLAN signal after the first spectrum shift according to the first frequency band includes:

carrying out first spectrum shifting on the WLAN signal according to a first frequency band according to a preset working channel and working bandwidth;

switching the filter to a first frequency band and filtering the WLAN signal after the first time of spectrum shifting;

and carrying out coarse synchronization on the filtered WLAN signal.

Taking 36 channels as an example, the receiving frequency point of the receiver is set as the central frequency point of the working bandwidth, for example:

the channel number is 36, the working bandwidth is 20MHz, and the receiving frequency point is 5180 MHz;

the channel number is 36, the working bandwidth is 40MHz, and the receiving frequency point is 5190 MHz;

the channel number is 36, the working bandwidth is 80MHz, and the receiving frequency point is 5210 MHz;

channel number 36, working bandwidth 160MHz, and receiving frequency point 5250 MHz.

For the receiver, it configures the working channel and working bandwidth in advance, and the receiver can receive the signal not exceeding the working bandwidth, but since the signal bandwidth is unknown at the beginning, it is known from the WLAN frame format, and can use 20M frequency domain data to perform synchronization acquisition. In the embodiment of the invention, the WLAN signal is shifted to the central frequency point of 20M, then the signal after the frequency spectrum shift is input to a 20M filter (designed according to zero intermediate frequency) for filtering, and finally the signal after the 20M filter is utilized for coarse synchronization, so that the signal can be determined under the condition of unknown signal bandwidth.

In an optional embodiment, the performing the second spectrum shifting on the WLAN signal according to the second frequency band, and performing fourier transform on the WLAN signal after the second spectrum shifting after filtering according to the second frequency band to obtain frequency domain data includes:

carrying out second spectrum shifting on the WLAN signal according to a second frequency band according to a preset working channel and working bandwidth;

switching the filter to a second frequency band and filtering the WLAN signal after the second time of frequency spectrum shifting;

and carrying out Fourier transform on the filtered WLAN signal to obtain frequency domain data.

After coarse synchronization, the WLAN signal is moved to the central frequency point of the working bandwidth according to 40M, and then a fourier transform interface is performed on the filtered signal through a 40M filter (designed according to zero intermediate frequency) to obtain 128-point frequency domain data. Which includes 20M frequency domain data and 40M frequency domain data. For example, in the HT-GF frame format bandwidth of 20M, two more subcarriers need to be estimated in the 40M frequency domain data of the HT-LTF1, and the spectrum shifting is performed.

In an optional embodiment, the selecting, from the frequency domain data, a subcarrier corresponding to the first frequency band for demodulation, and determining a signal bandwidth, a frame format, a number of space-time streams, and a number of extended spatial streams of the WLAN signal include:

extracting a subcarrier corresponding to the first frequency band from the frequency domain data;

demodulating the subcarrier to obtain a signaling domain of the WLAN signal;

and determining the signal bandwidth, the frame format, the number of space-time streams and the number of extended spatial streams of the WLAN signal according to the signaling domain.

Illustratively, the signaling domain of the 20M frequency domain data carries the bandwidth used for transmitting the data domain, the modulation technique used in the data domain, the number of spread spatial streams and/or space-time streams. Therefore, by demodulating the 20M subcarriers, the modulation mode and content of the signaling domain (XX-SIG, i.e., signal domain) of the WLAN signal can be obtained, so that the expanded spatial stream, the number of space-time streams, the signal bandwidth, and the frame format of the data domain can be obtained according to the modulation mode and content of the signal domain.

In an optional embodiment, the performing the third spectrum shifting on the WLAN signal according to the signal bandwidth and filtering according to the signal bandwidth includes:

carrying out third time spectrum shifting on the WLAN signal according to the signal bandwidth;

and switching the filter to the signal bandwidth and filtering the WLAN signal after the third time of spectrum shifting.

In the embodiment of the invention, after the signal bandwidth is determined, the WLAN signal is moved to the central frequency point of the signal bandwidth, and then the signal filter after the frequency spectrum is moved is switched to the corresponding bandwidth for filtering processing, so that the problem of long switching time of the receiving frequency point can be avoided.

In an optional embodiment, the performing channel estimation and equalization demodulation on the WLAN signal after the third time spectrum shifting according to the signal bandwidth, the frame format, the number of space-time streams, and the number of spread spatial streams includes:

performing channel estimation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the number of space-time streams and the number of expanded space streams;

and performing equalization demodulation on the data domain of the WLAN signal according to the channel estimation result, the signal bandwidth and the frame format.

Further, the determining the signal bandwidth, the frame format, the number of space-time streams, and the number of extended spatial streams of the WLAN signal according to the signaling domain includes:

in an optional embodiment, the determining the signal bandwidth, the frame format, the number of space-time streams, and the number of extended spatial streams of the WLAN signal according to the signaling domain includes:

after the WLAN signal is coarsely synchronized, judging whether the modulation mode of the 5 th time domain symbol of the WLAN signal is BPSK;

if not, the frame format of the WLAN signal is an HT-GF frame format;

if yes, judging whether the modulation mode of the 6 th time domain symbol of the WLAN signal is BPSK;

if not, the frame format of the WLAN signal is an HT-MF frame format;

if yes, judging whether the modulation mode of the 7 th time domain symbol of the WLAN signal is QBPSK;

if so, the frame format of the WLAN signal is a VHT frame format;

if not, the frame format of the WLAN signal is a NonHT frame format;

and determining the signal bandwidth, the number of space-time streams and the number of extended spatial streams of the WLAN signal according to the determined frame format of the WLAN signal.

In an optional embodiment, the determining the signal bandwidth, the number of space-time streams and the number of extended spatial streams of the WLAN signal according to the determined frame format of the WLAN signal includes:

judging whether the frame format of the WLAN signal is a NonHT frame format or not;

if so, the signal bandwidth of the WLAN signal is 20M, the corresponding number of space-time streams is 1, and the corresponding number of extended space streams is 0;

if not, judging whether the frame format of the WLAN signal is an HT-MF frame format or an HT-GF frame format;

if yes, analyzing corresponding signal bandwidth, space-time stream number and expanded space stream number from the HT-SIG domain of the WLAN signal;

if not, judging that the frame format of the WLAN signal is a VHT frame format, analyzing corresponding signal bandwidth and space-time stream number from a VHT-SIG-A domain of the WLAN signal, and determining that the number of the expanded space streams of the WLAN signal is 0.

Further, before the frame format of the WLAN signal is determined to be a non ht frame format or a VHT frame format, equalizing a 6 th time domain symbol and a 7 th time domain symbol of the WLAN signal according to a non ht frame format data field;

judging whether the frame format of the WLAN signal is a NonHT frame format;

if yes, demodulating according to DATA DATA of the WLAN signal;

if not, the data demodulation is not carried out.

For the 802.11 series protocol standards, one space-time stream/extended spatial stream corresponds to one X-LTF; illustratively, 11a has only one space-time stream, and the channel estimation can be performed using the L-LTF. The 11n-MF refers to a plurality of space-time streams, so that a plurality of HT-LTFs exist, and the channel estimation needs the plurality of HT-LTFs to be used for equalization of a subsequent data domain; the spread spatial streams also correspond to corresponding HT-LTFs, which may be used for channel estimation, for sounding the channel, and not for equalization. The channel estimation of 11n-GF requires the use of the second symbol of HT-LTF1 in conjunction with the HT-LTF for the following space-time stream for equalization in the data domain, and the HT-LTF for the extended spatial stream is also used for the sounding channel and not for equalization. 11ac uses VHT-LTF corresponding to the number of space stream to carry out channel estimation and data domain equalization, and the protocol has no expanded space stream.

After the number of the space-time streams and the number of the expanded space streams are demodulated, channel estimation and balanced demodulation can be carried out on a data domain of the WLAN signal after the subsequent xx-LTF signal and the data signal arrive, and therefore a corresponding sending signal is restored. When the rate in the L-SIG of 11a is 6M, the modulation mode of the first symbol of DATA of 11a is consistent with the modulation mode of the first symbol of VHT-SIG-a of 11ac, and the frame format of the signal cannot be determined, at this time, the DATA field is equalized according to 11a, and demodulation is performed after the frame format is determined, as shown in fig. 4.

Compared with the prior art, the embodiment of the invention has the beneficial effects that: signals are subjected to 20M spectrum shifting, 20M filtering, coarse synchronization, 40M spectrum shifting, 40M filtering, spectrum shifting according to signal bandwidth, filtering according to signal bandwidth, channel estimation and equalization demodulation processing, WLAN signals with different bandwidths can be analyzed in real time under the condition of unknown signal bandwidth, time domain data of HT-LTF1 do not need to be cached, physical space is saved, real-time performance is good, processing delay is small, and meanwhile, the HT-GF mode can be compatible.

Example two

Referring to fig. 5, a receiver for resolving a WLAN signal according to an embodiment of the present invention includes:

the first signal processing module 1 is configured to perform first frequency spectrum shifting on a received WLAN signal according to a first frequency band, and perform coarse synchronization after filtering the WLAN signal after the first frequency spectrum shifting according to the first frequency band;

the second signal processing module 2 is configured to perform, after coarse synchronization is completed, second frequency spectrum shifting on the WLAN signal according to a second frequency band, perform fourier transform on the WLAN signal after the second frequency spectrum shifting after filtering according to the second frequency band, and obtain frequency domain data;

a first demodulation module 3, configured to select a subcarrier corresponding to the first frequency band from the frequency domain data to demodulate, and determine a signal bandwidth, a frame format, a number of space-time streams, and a number of extended spatial streams of the WLAN signal;

the third signal processing module 4 is configured to perform third time spectrum shifting on the WLAN signal according to a signal bandwidth, and perform filtering according to the signal bandwidth;

and the second demodulation module 5 is configured to perform channel estimation and equalization demodulation on the WLAN signal after the third time of spectrum shift according to the signal bandwidth, the frame format, the number of space-time streams, and the number of spread spatial streams.

In an alternative embodiment, the first signal processing module 1 comprises:

the first spectrum moving unit is used for carrying out first spectrum moving on the WLAN signal according to a first frequency band according to a preset working channel and working bandwidth;

the first filtering unit is used for switching the filter to a first frequency band and filtering the WLAN signal after the first time of spectrum shifting;

and the coarse synchronization unit is used for performing coarse synchronization on the filtered WLAN signal.

In an alternative embodiment, the second signal processing module 2 comprises:

the second spectrum moving unit is used for carrying out second spectrum moving on the WLAN signal according to a second frequency band according to a preset working channel and working bandwidth;

the second filtering unit is used for switching the filter to a second frequency band and filtering the WLAN signal after the second time of frequency spectrum shifting;

and the Fourier transform unit is used for carrying out Fourier transform on the filtered WLAN signal to obtain frequency domain data.

In an alternative embodiment, the first demodulation module 3 comprises:

a subcarrier extraction unit configured to extract subcarriers corresponding to the first frequency band from the frequency domain data;

a subcarrier demodulation unit, configured to demodulate the subcarrier to obtain a signaling domain of the WLAN signal;

and the signaling domain demodulation unit is used for determining the signal bandwidth, the frame format, the number of space-time streams and the number of extended space streams of the WLAN signal according to the signaling domain.

In an alternative embodiment, the third signal processing module 4 comprises:

the third spectrum shifting unit is used for carrying out third spectrum shifting on the WLAN signal according to the signal bandwidth;

and the third filtering unit is used for switching the filter to the signal bandwidth and filtering the WLAN signal after the third time of spectrum shifting.

In an alternative embodiment, the second demodulation module 5 comprises:

the channel estimation unit is used for carrying out channel estimation on the WLAN signal subjected to the third time of frequency spectrum shifting according to the signal bandwidth, the number of space-time streams and the number of expanded space streams;

and the equalization demodulation unit is used for carrying out equalization demodulation on the data domain of the WLAN signal according to the channel estimation result, the signal bandwidth and the frame format.

In an alternative embodiment, the signaling domain demodulation unit includes:

a first determining unit, configured to determine whether a modulation mode of a 5 th time domain symbol of the WLAN signal is BPSK after the WLAN signal is coarsely synchronized;

a first frame format determining unit, configured to determine, if the frame format of the WLAN signal is not the HT-GF frame format;

a second determining unit, configured to determine whether a modulation mode of a 6 th time domain symbol of the WLAN signal is BPSK if the modulation mode is the BPSK;

a second frame format determining unit, configured to determine, if the frame format of the WLAN signal is not the HT-MF frame format;

a third determining unit, configured to determine whether a modulation mode of a 7 th time domain symbol of the WLAN signal is QBPSK if yes;

a third frame format determining unit, configured to determine, if yes, that a frame format of the WLAN signal is a VHT frame format;

a fourth frame format determining unit, configured to determine that the frame format of the WLAN signal is a non ht frame format if no;

and the signal parameter determining unit is used for determining the signal bandwidth, the number of space-time streams and the number of extended spatial streams of the WLAN signal according to the determined frame format of the WLAN signal.

In an alternative embodiment, the signal parameter determination unit comprises:

a fourth judging unit, configured to judge whether a frame format of the WLAN signal is a non ht frame format;

a first signal parameter determining unit, configured to, if yes, set a signal bandwidth of the WLAN signal to be 20M, set a corresponding number of space-time streams to be 1, and set a corresponding number of extended space streams to be 0;

a fifth judging unit, configured to judge whether a frame format of the WLAN signal is an HT-MF frame format or an HT-GF frame format if the frame format of the WLAN signal is not the HT-MF frame format;

a first signal parameter analyzing unit, configured to analyze, if yes, a corresponding signal bandwidth, a number of space-time streams, and a number of extended space streams from an HT-SIG field of the WLAN signal;

and if not, determining that the frame format of the WLAN signal is the VHT frame format, analyzing a corresponding signal bandwidth and a corresponding number of space-time streams from the VHT-SIG-a domain of the WLAN signal, and determining that the number of extended space streams of the WLAN signal is 0.

EXAMPLE III

Referring to fig. 6, an apparatus for analyzing a WLAN signal according to an embodiment of the present invention includes a processor 112 and a communication module 113; wherein the communication module is coupled to the processor, and the processor is configured to run a computer program to implement the method for resolving a WLAN signal according to any one of the first embodiment, and the communication module is configured to communicate with other modules besides a device for resolving a WLAN signal.

The processor 112 may be, among other things, a central processing unit, a general purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, transistor logic, a hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. Processor 112 may also be a combination of computing functions, e.g., including one or more microprocessors in combination, a digital signal processor and a microprocessor in combination, or the like. The communication module 113 may be a communication interface, a transceiver, a transceiving circuit or an interface circuit, etc.

The apparatus for resolving WLAN signals further comprises a memory 111, and the memory 111 may comprise a read only memory and a random access memory and provides operating instructions and data to a processor 112. A portion of memory 111 may also include non-volatile random access memory (NVRAM).

In some embodiments, memory 111 stores elements, executable modules or data structures, or a subset thereof, or an expanded set thereof:

in the embodiment of the present invention, by calling the operation instruction stored in the memory 111 (the operation instruction may be stored in the operating system), the corresponding operation is executed.

The processor 112 controls the operation of the various devices, and the processor 112 may also be referred to as a Central Processing Unit (CPU). Memory 111 may include both read-only memory and random access memory and provides instructions and data to processor 112. A portion of memory 111 may also include non-volatile random access memory (NVRAM). For example, in applications where the memory, communication interface, and memory are coupled together by a bus system that may include a power bus, a control bus, a status signal bus, etc., in addition to a data bus.

The method disclosed by the above-mentioned embodiments of the present invention can be applied to the processor 112, or implemented by the processor 112. The processor 112 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 112. The processor 112 may be a general purpose processor, a Digital Signal Processor (DSP), 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, or discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 111, and the processor 112 reads the information in the memory 111 and completes the steps of the method in combination with the hardware thereof.

In the above embodiments, the instructions stored by the memory for execution by the processor may be implemented in the form of a computer program product. The computer program product may be written in the memory in advance or may be downloaded in the form of software and installed in the memory.

The computer program product includes one or more computer instructions. The procedures or functions according to the embodiments of the present application are all or partially generated when the computer program instructions are loaded and executed on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, e.g., the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. A computer-readable storage medium may be any available medium that a computer can store or a data storage device including one or more available media integrated servers, data centers, and the like. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

The fourth embodiment of the invention also provides a computer readable storage medium. The methods described in the above embodiments may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media may include computer storage media and communication media, and may include any medium that can communicate a computer program from one place to another. A storage medium may be any target medium that can be accessed by a computer.

As an alternative embodiment, a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be targeted for carriage or store desired program code in the form of instructions or data structures and which can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

The embodiment of the invention also provides a computer program product. The methods described in the above embodiments may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. If implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The procedures or functions described in the above method embodiments are generated in whole or in part when the above computer program instructions are loaded and executed on a computer. The computer may be a general purpose computer, a special purpose computer, a computer network, a base station, a terminal, or other programmable device.

It should be noted that the above-described device embodiments are merely illustrative, where the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. In addition, in the drawings of the embodiment of the apparatus provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, and may be specifically implemented as one or more communication buses or signal lines. One of ordinary skill in the art can understand and implement it without inventive effort.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.