A wireless channel CSI acquisition method, system and computer readable storage medium

Abstract

The embodiment of the application provides a wireless channel CSI acquisition method, system and computer readable storage medium, the method comprises the following steps: obtaining test signal information through a signal transmitter and converting the test signal information into a test signal; wherein the test signal comprises verification information; receiving the test signal through a signal receiver and extracting the verification information from the test signal; and performing a verification process on the verification information; in the case of passing the verification, obtaining sampling signal information through the signal transmitter and converting the sampling signal information into a sampling signal; wherein the verification information in the sampling signal is empty; receiving the sampling signal through the signal receiver and extracting channel state information (CSI) from the sampling signal. Through the above technical solution, the sampling efficiency of the CSI can be improved, thereby improving the accuracy of wireless perception.

Description

Technical Field

[0001] This application relates to the field of wireless sensing, and in particular to a wireless channel CSI acquisition method, system, and computer-readable storage medium. Background Technology

[0002] In recent years, due to the rapid development of Wi-Fi technology and the soaring communication demands of mobile users, wireless sensing technology has gradually come into the public eye. Compared with traditional wearable devices, wireless sensing technology only requires the deployment of a small number of wireless signal transceivers in the sensing scene to achieve similar sensing effects. Furthermore, compared to visual sensing technology, wireless sensing technology does not require photographing people and backgrounds in the scene, providing higher security and privacy for users. The foundation of wireless sensing technology is the collection of Channel State Information (CSI) in the environment; however, existing CSI sampling methods suffer from low efficiency, resulting in insufficient accuracy in wireless sensing.

[0003] Application content

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, embodiments of this application propose a wireless channel CSI acquisition method that can improve CSI sampling efficiency, thereby enhancing the accuracy of wireless sensing.

[0005] This application also proposes a wireless channel CSI acquisition system that applies the above-described wireless channel CSI acquisition method.

[0006] This application also proposes a computer-readable storage medium that applies the above-described wireless channel CSI acquisition method.

[0007] The first aspect of this application provides a wireless channel CSI acquisition method, applied to a wireless channel CSI acquisition system, the wireless channel CSI acquisition system including a signal transmitter and a signal receiver, the method comprising:

[0008] The signal transmitter acquires test signal information and converts the test signal information into a test signal; wherein the test signal includes verification information.

[0009] The test signal is received by the signal receiver and verification information is extracted from the test signal; and the verification information is verified.

[0010] If the verification passes, the sampling signal information is acquired through the signal transmitter and converted into a sampling signal; wherein, the verification information in the sampling signal is empty;

[0011] The sampling signal is received by the signal receiver and the channel state information (CSI) is extracted from the sampling signal.

[0012] According to some embodiments of this application, the signal transmitter includes a first host computer and a Universal Software Radio Peripheral (USRP) transmitter. The step of acquiring test signal information through the signal transmitter and converting the test signal information into a test signal includes:

[0013] The test signal information is obtained through the first host computer;

[0014] The test signal information is converted into the test signal by the USRP transmitter.

[0015] According to some embodiments of this application, the signal receiver includes a second host computer and a USRP receiver. The step of receiving the test signal through the signal receiver and extracting verification information from the test signal includes:

[0016] The test signal is received by the USRP receiver and converted into test information.

[0017] The verification information is extracted from the test information by the second host computer.

[0018] According to some embodiments of this application, the signal reception period, signal reception bandwidth, and channel number of the first host computer and the second host computer are all the same.

[0019] According to some embodiments of this application, both the test signal and the sampling signal are Wi-Fi signals, wherein the Wi-Fi signal includes a short training field, a long training field, a signaling field, and a valid data field.

[0020] According to some embodiments of this application, the verification information is the valid data field, and both the signaling field and the valid data field in the sampling signal are empty.

[0021] According to some embodiments of this application, when the bit error rate of the valid data field in the signal receiver is less than a preset threshold, it indicates that the verification information has passed the verification.

[0022] According to some embodiments of this application, extracting channel state information (CSI) from the sampled signal includes:

[0023] The long training field is obtained by grouping and truncating the sampled signal using the signal receiver.

[0024] Frequency domain information is obtained by performing a Fast Fourier Transform on the long training field;

[0025] The frequency domain information is compared with a preset local long training field to obtain the channel state information (CSI).

[0026] A second aspect of this application provides a wireless channel CSI acquisition system, including a signal transmitter and a signal receiver; wherein the signal transmitter and the signal receiver are used to perform the wireless channel CSI acquisition method described above.

[0027] A third aspect of this application provides a computer-readable storage medium storing computer-executable instructions that, when executed by a control processor, implement the wireless channel CSI acquisition method described above.

[0028] The wireless channel CSI acquisition method according to the embodiments of this application has at least the following beneficial effects: The wireless channel CSI acquisition method is applied to a wireless channel CSI acquisition system, wherein the wireless channel CSI acquisition system includes a signal transmitter and a signal receiver; during the CSI acquisition process, test signal information is first acquired through the signal transmitter, and then the test signal information is converted into a test signal, wherein the test signal includes verification information; then the test signal is received through the signal receiver, and the verification information is extracted from the test signal and verified; if the verification passes, sampling signal information is acquired through the signal transmitter and converted into a sampling signal, wherein the verification information in the sampling signal is empty; the sampling signal is received through the signal receiver and CSI is extracted from the sampling signal; during the sampling process, the verification information in the test signal is first verified to check the sampling reliability of the system, and if the verification passes, the sampling process is performed again, and the verification information in the sampling signal is made empty during the sampling process, thereby enabling more sampling signals to be sent per unit time, improving the sampling efficiency of CSI, and thus improving the accuracy of wireless sensing.

[0029] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0030] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0031] Figure 1 This is a schematic diagram of a system architecture for performing a wireless channel CSI acquisition method, provided in an embodiment of this application.

[0032] Figure 2A flowchart of the wireless channel CSI acquisition method provided in the embodiments of this application;

[0033] Figure 3 A flowchart of the transmission test signal provided in the embodiments of this application;

[0034] Figure 4 A flowchart illustrating the receiving of test signals provided in this application embodiment;

[0035] Figure 5 A flowchart for obtaining channel state information provided in an embodiment of this application;

[0036] Figure 6 A schematic diagram of the physical layer format of Wi-Fi signals as specified in the 801.11a protocol provided for embodiments of this application;

[0037] Figure 7 The LabVIEW interface for setting WIFI transmitter transmission parameters in test mode provided in this application embodiment;

[0038] Figure 8 The LabVIEW interface for setting WIFI receiver reception parameters and displaying waveforms in the test mode provided in this application embodiment;

[0039] Figure 9 LabVIEW interface for setting WIFI transmitter transmission parameters in sampling mode as provided in the embodiments of this application;

[0040] Figure 10 The LabVIEW interface for setting WIFI receiver reception parameters and displaying waveforms in the sampling mode provided in this application embodiment. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0042] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0043] The embodiments of this application will be further described below with reference to the accompanying drawings.

[0044] like Figure 1 As shown, Figure 1 This is a schematic diagram of a system architecture for performing a wireless channel CSI acquisition method according to an embodiment of this application. Figure 1 In the example, the system architecture includes a signal transmitter and a signal receiver. The signal transmitter includes a first host computer and a USRP transmitter, and the signal receiver includes a second host computer and a USRP receiver. The first host computer is electrically connected to the USRP transmitter, and the second host computer is electrically connected to the USRP receiver. Wireless signal transmission is possible between the USRP transmitter and the USRP receiver. It should be noted that... Figure 1 This is merely an illustrative description of the system architecture for implementing the wireless channel CSI acquisition method. It is an example provided only to facilitate a detailed explanation of the subsequent technical solutions and should not be assumed that the system architecture only contains a first host computer, a USRP transmitter, a second host computer, and a USRP receiver.

[0045] The system architecture and application scenarios described in this application are intended to more clearly illustrate the technical solutions of this application and do not constitute a limitation on the technical solutions provided in this application. Those skilled in the art will understand that as system architectures evolve and new application scenarios emerge, the technical solutions provided in this application are also applicable to similar technical problems.

[0046] It will be understood by those skilled in the art that Figure 1 The system architecture shown does not constitute a limitation on the embodiments of this application. It may include more or fewer components than shown, or combine certain components, or have different component arrangements. Based on the structure of the above system architecture, various embodiments of the wireless channel CSI acquisition method of this application are proposed.

[0047] like Figure 2 As shown, Figure 2 This is a flowchart of a wireless channel CSI acquisition method provided in one embodiment of this application. The wireless channel CSI acquisition method is applied to a wireless channel CSI acquisition system, which includes a signal transmitter and a signal receiver. The wireless channel CSI acquisition method includes, but is not limited to, steps S100, S200, S300, and S400.

[0048] Step S100: Acquire test signal information through a signal transmitter and convert the test signal information into a test signal; wherein, the test signal includes verification information;

[0049] Step S200: Receive test signals through a signal receiver and extract verification information from the test signals; and perform verification processing on the verification information;

[0050] Step S300: If the verification passes, the sampling signal information is acquired through the signal transmitter and converted into a sampling signal; wherein, the verification information in the sampling signal is empty;

[0051] Step S400: Receive the sampled signal through the signal receiver and extract the Channel State Information (CSI) from the sampled signal.

[0052] It should be noted that the wireless channel CSI acquisition method is applied to a wireless channel CSI acquisition system, which includes a signal transmitter and a signal receiver. During CSI acquisition, the signal transmitter first acquires test signal information, then converts it into a test signal, which includes verification information. The signal receiver then receives the test signal, extracts the verification information, and performs verification processing on the verification information. If the verification passes, the signal transmitter acquires sampling signal information and converts it into a sampled signal, where the verification information is empty. The signal receiver receives the sampled signal and extracts CSI from it. During sampling, verification processing is first performed based on the verification information in the test signal to verify the system's sampling reliability. If the verification passes, sampling is then performed. Furthermore, the verification information in the sampled signal is kept empty during sampling, allowing more sampled signals to be sent per unit time, improving CSI sampling efficiency and thus enhancing the accuracy of wireless sensing.

[0053] It is worth noting that CSI stands for Channel State Information, which is the channel attribute of the communication link. It describes the attenuation factor of the signal on each transmission path, that is, the value of each element in the channel gain matrix, such as signal scattering, environmental attenuation, and distance attenuation.

[0054] It is understood that both the test signal information and the sampling signal information can be editable signal parameter information, and the test signal and the sampling signal are signals generated based on the signal parameter information. For example, when the test signal is a WIFI signal, the signaling field and the valid data field of the WIFI signal can be edited to make the generated WIFI signal have corresponding parameter characteristics.

[0055] It is worth noting that the test signal and the sampling signal are the same type of signal; the test signal includes verification information, and the verification information is not empty, so that reliability verification can be performed before CSI sampling; after verifying reliability, the verification information in the sampling signal can be set to empty, so that more information can be received per unit time, improving sampling efficiency and thus improving the accuracy of wireless sensing.

[0056] In some embodiments, such as Figure 3 As shown, the signal transmitter includes a first host computer and a Universal Software Radio Peripheral (USRP) transmitter. The above step S100 may include, but is not limited to, steps S110 and S120.

[0057] Step S110: Obtain test signal information through the first host computer;

[0058] Step S120: Convert the test signal information into a test signal using the USRP transmitter.

[0059] It should be noted that in the process of acquiring test signal information using a signal transmitter and converting the test signal information into a test signal, the first host computer first acquires the test signal information, and then the first host computer transmits the received test signal information to the USRP transmitter. The USRP transmitter converts the test signal information into a test signal, and the test signal also includes verification information, so as to facilitate the system reliability verification process on the signal receiver side.

[0060] In some embodiments, such as Figure 4 As shown, the signal receiver includes a second host computer and a USRP receiver, and the above step S200 may include, but is not limited to, steps S210 and S220.

[0061] Step S210: Receive the test signal through the USRP receiver and convert the test signal into test information;

[0062] Step S220: Extract verification information from the test information via the second host computer.

[0063] It should be noted that in the process of receiving test signals and extracting verification information from test signals using a signal receiver, the test signals are first received by the USRP receiver and converted into test information; then the verification information is extracted from the test information by the second host computer, and then the verification information is verified by the second host computer to verify the reliability of the wireless channel CSI acquisition system.

[0064] In some embodiments, the signal reception period, signal reception bandwidth, and channel number of the first host computer and the second host computer are consistent, so that the signal transmitter and the signal receiver can correspond to each other during the test sampling process, so as to facilitate signal testing and sampling processing.

[0065] like Figure 6As shown, in some embodiments, both the test signal and the sampling signal are Wi-Fi signals. The Wi-Fi signal includes a short training field, a long training field, a signaling field, and a valid data field. It should be noted that the short training field is used for packet start detection and automatic gain control settings, as well as initial frequency offset estimation and initial time synchronization; the long training field is used for channel estimation and more accurate frequency offset estimation and time synchronization; the signaling field contains the rate and length information of the Wi-Fi packet, and the rate information of the signaling field determines the modulation type and coding rate of the subsequent data field; the valid data field includes a 16-bit service field, data bit tail bits, and padding bits only when needed.

[0066] In some embodiments, the verification information is a valid data field, while the signaling field and valid data field in the sampling signal are both empty. With both the signaling field and valid data field in the sampling signal empty, the time occupied by the transmitted WIFI packets is further reduced, and more WIFI signals can be transmitted per unit time to measure the channel state information in the environment, thereby achieving a higher CSI sampling rate.

[0067] In some embodiments, the verification of the verification information is considered successful if the bit error rate of the valid data field in the signal receiver is less than a preset threshold. During the reliability verification of the wireless channel CSI acquisition system, the verification of the verification information is considered successful only if the bit error rate of the valid data field in the signal receiver is less than the preset threshold.

[0068] In some embodiments, such as Figure 5 As shown, step S400 may include, but is not limited to, steps S410, S420 and S430.

[0069] Step S410: The sampled signal is processed by the signal receiver to obtain a long training field by grouping and truncation.

[0070] Step S420: Perform Fast Fourier Transform on the long training field to obtain frequency domain information;

[0071] Step S430: Compare the frequency domain information with the preset local long training field to obtain the channel state information (CSI).

[0072] It should be noted that in the process of extracting Channel State Information (CSI), the sampled signal is first processed by the signal receiver to obtain a long training field by grouping and truncation; then the long training field is processed by Fast Fourier Transform to obtain frequency domain information; then the frequency domain information is compared with the preset local long training field to obtain the Channel State Information (CSI).

[0073] To more clearly illustrate the flow of the wireless channel CSI acquisition method provided in this application embodiment, a specific example is given below.

[0074] like Figures 7 to 8 As shown, the host computers of both the Wi-Fi transmitter and receiver are in test mode (i.e., acquisition mode is off). The required transmit array data (12) is input, and the transmitter and receiver programs are run. The receiver acquires the CSI amplitude and phase images and restores the transmitter's transmitted array data to 12, indicating that the system has acquired accurate CSI data. During the test, according to the 802.11a protocol, the transmitter uses LabVIEW to program the generation of short training fields, long training fields, signaling fields, and valid data fields, and combines these fields into Wi-Fi packets. The receiver performs tasks such as synchronizing and demodulating the Wi-Fi packets, and controls the USRP to transmit and receive Wi-Fi signals via Ethernet. The accuracy of the acquisition system is determined by the bit error rate of the valid data field demodulated from the acquired CSI data.

[0075] like Figure 9 The host computer of the WIFI transmitter opens the sampling mode, sets the WIFI signal transmission period to 54.6μs, the WIFI signal transmission bandwidth to 20MHz (range: 5MHz-20MHz), and the WIFI channel number to 13 (range: 1-13, referring to 2.142G-2.472GHz). It runs the transmitter program, which generates a wireless WIFI signal with the corresponding period, bandwidth, and carrier, and transmits the corresponding WIFI signal through Ethernet-controlled USRP radio frequency modulation.

[0076] Based on the 802.11a protocol, this application preferably designs Wi-Fi packets containing empty signaling and data fields, and uses LabVIEW to program the generation of Wi-Fi packets. Note that the inclusion of empty signaling and data fields in the packets reduces redundancy and is both reasonable and effective. This is because the system's reliability has been verified through test mode. Afterward, environmental CSI measurements do not require the use of the signaling and data fields in the packets, allowing the use of Wi-Fi packets containing empty signaling and data fields in a unique sampling mode. This design further reduces the time occupied by transmitted Wi-Fi packets, allowing more Wi-Fi signals to be transmitted per unit time to measure channel state information in the environment, thereby achieving a higher CSI sampling rate. Based on the above settings, and by setting program parameters according to the required Wi-Fi signal transmission period, bandwidth, channel, etc., the configured signal is finally transmitted via Ethernet control of the USRP.

[0077] like Figure 10 The WIFI receiver's host computer is set to sampling mode, with the WIFI signal reception period set to 54.6μs, the WIFI signal reception bandwidth to 20MHz (range: 5MHz-20MHz), the WIFI channel number to 13 (range: 1-13, referring to 2.412G-2.472GHz), the CSI sampling rate to 1000Hz, and the CSI resolution to 385kHz. The transmitter parameters are set in the same manner as described above. After completing the relevant settings, the transmitter and receiver host computer programs are run. The transmitter USRP sends WIFI signals, and the receiver USRP receives the corresponding WIFI signals. It then transmits the I and Q signals via Ethernet to the receiver host computer, displaying and storing the amplitude and phase of the CSI information on the 52 subcarriers in real time.

[0078] Based on the 802.11a protocol and the design of empty signaling and data fields in the sampling mode of this application, a program was written using LabVIEW to set the same WIFI and CSI parameters as the transmitter, and control the USRP to collect signals on the corresponding WIFI channel. After frequency synchronization and time synchronization, a relatively accurate received signal was obtained. Then, a long training field was extracted according to the packet format, and the frequency domain information of the received long training field was obtained through FFT. The CSI data was obtained by comparing it with the local long training field. Finally, the obtained CSI data was stored to complete the acquisition.

[0079] like Figure 1 As shown, a second aspect of this application proposes a wireless channel CSI acquisition system, including a signal transmitter and a signal receiver; wherein the signal transmitter and the signal receiver are used to perform the wireless channel CSI acquisition method described above.

[0080] It should be noted that since the wireless channel CSI acquisition method in this embodiment is based on the same inventive concept as the wireless channel CSI acquisition method in the above embodiments, the corresponding content in the method embodiment is also applicable to this system embodiment, and will not be repeated here.

[0081] According to an embodiment of a third aspect of the present invention, a computer-readable storage medium is provided, which stores computer-executable instructions that, when executed by a control processor, implement the highway crack image segmentation method described above. For example, the method described above... Figure 2 Method steps S100 to S400, Figure 3 Method steps S110 to S120, Figure 4 Method steps S210 to S220, Figure 5 Method steps S410 to S430.

[0082] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0083] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A wireless channel CSI acquisition method, characterized in that, The method is applied to a wireless channel CSI acquisition system, the wireless channel CSI acquisition system comprising a signal transmitter and a signal receiver, and the method comprising: acquiring test signal information by the signal transmitter and converting the test signal information into a test signal; wherein the test signal comprises verification information; receiving the test signal by the signal receiver and extracting the verification information from the test signal; and performing a check on the verification information; in the case of a check pass, acquiring sampling signal information by the signal transmitter and converting the sampling signal information into a sampling signal; wherein the verification information in the sampling signal is empty; receiving the sampling signal by the signal receiver and extracting channel state information (CSI) from the sampling signal.

2. The wireless channel CSI acquisition method of claim 1, wherein, The signal transmitter comprises a first host computer and a universal software radio peripheral (USRP) transmitter, and the acquiring test signal information by the signal transmitter and converting the test signal information into a test signal comprises: acquiring the test signal information by the first host computer; converting the test signal information into the test signal by the USRP transmitter.

3. The wireless channel CSI acquisition method of claim 2, wherein, The signal receiver comprises a second host computer and a USRP receiver, and the receiving the test signal by the signal receiver and extracting the verification information from the test signal comprises: receiving the test signal by the USRP receiver and converting the test signal into test information; extracting the verification information from the test information by the second host computer.

4. The wireless channel CSI acquisition method of claim 3, wherein, The signal receiving period, signal receiving bandwidth and channel number of the first host computer and the second host computer are consistent.

5. The wireless channel CSI acquisition method of claim 1, wherein, The test signal and the sampling signal are both WIFI signals, wherein the WIFI signal comprises a short training field, a long training field, a signaling field and a valid data field.

6. The wireless channel CSI acquisition method of claim 5, wherein, The verification information is the valid data field, and the signaling field and the valid data field in the sampling signal are both empty.

7. The wireless channel CSI acquisition method of claim 5, wherein, In the case that the error rate of the valid data field in the signal receiver is less than a preset threshold, it is indicated that the check on the verification information is passed.

8. The wireless channel CSI acquisition method of claim 5, wherein, The extracting channel state information (CSI) from the sampling signal comprises: grouping and intercepting the sampling signal by the signal receiver to obtain the long training field; performing fast Fourier transform on the long training field to obtain frequency domain information; comparing the frequency domain information with a preset local long training field to obtain the channel state information (CSI). 9.A wireless channel CSI acquisition system, characterized in that, The computer executable instructions, when executed by a control processor, implement the wireless channel CSI acquisition method as claimed in any one of claims 1 to 8.

10. A computer-readable storage medium, the computer-readable storage medium storing computer-executable instructions, wherein, The computer executable instructions, when executed by a control processor, implement the wireless channel CSI acquisition method as claimed in any one of claims 1 to 8.

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