WiFi signal processing method and device

Abstract

The invention provides a WiFi signal processing method and device, and the method comprises the steps: calculating target energy through employing an initial part of a first target field signal when the demodulation of the first target field signal corresponding to a first time position in a WiFi signal is started; the first time position is a time position corresponding to a VHT-STF field signal specified in a WiFi (Wireless Fidelity) protocol; calculating a variation range between the target energy and the reference energy; if the variation range does not exceed the threshold value, performing estimation DC operation by using the remaining part of the first target field signal; if the variation range exceeds the threshold value, the remaining portion of the first target field signal is used to perform a redo AGC operation and an estimation DC operation. In the scheme, whether to redo the AGC or not is determined according to the signal energy, and whether to use the estimated DC or not is determined after the DC is estimated, so that the purposes of timely redo the AGC and reserving enough time to estimate the DC are achieved under the condition that the cost is not increased.

Description

Technical Field

[0001] The present invention relates to the technical field of signal processing, and in particular to a method and device for processing WiFi signals. Background Art

[0002] Since WiFi4 introduced beamforming technology, it has brought challenges to the receiver's AGC (AutoGain Control), because beamforming technology enhances the received signal of the receiving antenna relative to that without beamforming, resulting in the AGC done in the Legacy signal segment (traditional 802.11g signal segment) no longer adapting to the beamforming signal segment, because the signal energy of the two signal segments may be quite different. For this reason, WiFi4 / 5 respectively set up HT / VHT STF (Short Training Field) signal segments to help the receiver redo AGC to adapt to the energy of the beamforming signal segment. Among them, redoing AGC means re-adjusting AGC, that is, using the energy of the HT / VHT STF signal segment to adjust the gain of the variable analog amplifier so that the signal energy entering the analog-to-digital converter is moderate.

[0003] At present, many devices will use part of the VHT-STF signal segment (4us in total) to redo AGC, and then use the remaining part to estimate DC (Direct Current), and then use the estimated DC to eliminate the DC in the signal. Since the 11g signal (i.e. WiFi3) does not redo AGC, it is necessary to use the 3.2us signal before the VHT-STF signal segment (if it exists) to determine whether it is an 11g or 11ac (WiFi5) signal. This poses a serious challenge to the processing speed of the receiver, because there is a delay from the air interface to the receiver processing point, and after receiving the 3.2us signal, it takes time to perform FFT (Fast Fourier transform) to the frequency domain, and finally use the signal after FFT to perform an algorithm to determine whether it is an 11g or 11ac signal, which also takes time. Therefore, usually when it is determined that it is an 11ac signal, a part of the VHT-STF signal segment has been consumed, and the VHT-STF signal segment is only 4us in total. After redoing AGC, the remaining part may no longer have enough length to estimate DC.

[0004] In the existing technology, one is to use the VHT-STF signal segment only to redo AGC, and to use notch to eliminate DC, which will sacrifice the performance of high-throughput communication. Another is to improve the hardware processing speed and quickly distinguish 11g signals from 11ac signals, which is more costly. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a method and device for processing WiFi signals, so as to achieve the purpose of timely redoing AGC and retaining sufficient time to estimate DC without increasing costs.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] A first aspect of an embodiment of the present invention discloses a method for processing a WiFi signal, the method comprising:

[0008] Receive WiFi signals in real time and demodulate the WiFi signals;

[0009] When it is determined that the WiFi signal belongs to any one of a 11g signal and a 11ac signal, and an L-Sig field signal in the WiFi signal is demodulated to obtain L-Sig field content, acquiring a rate level and a byte length of a frame payload from the L-Sig field content;

[0010] If the rate level is equal to the specified rate and the byte length is equal to a multiple of the specified value, then when demodulating the first target field signal corresponding to the first time position in the WiFi signal, the target energy is calculated using the initial part of the first target field signal; the first time position is the time position corresponding to the VHT-STF field signal specified in the WiFi5 protocol;

[0011] Calculating a variation range between the target energy and the reference energy; the reference energy is calculated using the Stf field signal when demodulating the Stf field signal in the WiFi signal;

[0012] If the variation range does not exceed the threshold value, using the remaining part of the first target field signal to perform an estimated DC operation;

[0013] If the variation range exceeds the threshold value, the redo AGC operation and the estimated DC operation are performed using the remaining portion of the first target field signal.

[0014] Preferably, the method further comprises:

[0015] If the rate level is not equal to the specified rate, or the byte length is not equal to a multiple of a specified value, it is determined that the WiFi signal belongs to an 11g signal, and the AGC operation and the estimated DC operation are not performed.

[0016] Preferably, the method further comprises:

[0017] When a signal characteristic is obtained by demodulating a second target field signal corresponding to a second time position in the WiFi signal, determining whether the WiFi signal belongs to the 11ac signal based on the signal characteristic; the second time position is a time position corresponding to a VHT-Sig2 field signal specified in the WiFi5 protocol;

[0018] If so, after performing the estimated DC operation to obtain the DC component, removing the DC component from the WiFi signal;

[0019] If not, it is determined that the WiFi signal belongs to the 11g signal, and after obtaining the DC component, the DC component is discarded.

[0020] Preferably, when the second target field signal corresponding to the second time position in the demodulated WiFi signal is obtained by obtaining a signal characteristic, judging whether the WiFi signal belongs to the 11ac signal based on the signal characteristic includes:

[0021] When a signal characteristic is obtained by demodulating the second target field signal corresponding to the second time position in the WiFi signal, determining whether the signal characteristic is consistent with a target signal characteristic of the VHT-Sig2 field signal specified in the WiFi5 protocol;

[0022] If yes, it is determined that the WiFi signal belongs to the 11ac signal;

[0023] If not, it is determined that the WiFi signal belongs to the 11g signal.

[0024] Preferably, the performing the redo AGC operation and the estimating DC operation using the remaining portion of the first target field signal comprises:

[0025] performing the redo AGC operation using a remaining portion of the first target field signal;

[0026] The estimated DC operation is performed using a remaining portion of the first target field signal after the redo AGC operation is completed.

[0027] A second aspect of an embodiment of the present invention discloses a device for processing WiFi signals, the device comprising:

[0028] A demodulation unit, used to receive WiFi signals in real time and demodulate the WiFi signals;

[0029] an acquiring unit, configured to acquire a rate level and a byte length of a frame payload from the L-Sig field content when it is determined that the WiFi signal belongs to any one of a 11g signal and a 11ac signal and an L-Sig field signal in the WiFi signal is demodulated to obtain L-Sig field content;

[0030] an energy calculation unit, configured to calculate a target energy using an initial portion of a first target field signal corresponding to a first time position in a WiFi signal when demodulating the first target field signal corresponding to a first time position in the WiFi signal if the rate level is equal to a specified rate and the byte length is equal to a multiple of a specified value; the first time position is a time position corresponding to a VHT-STF field signal specified in the WiFi5 protocol;

[0031] A variation range calculation unit, used to calculate the variation range between the target energy and the reference energy; the reference energy is calculated using the Stf field signal when demodulating the Stf field signal in the WiFi signal;

[0032] a first processing unit, configured to perform an estimated DC operation using a remaining portion of the first target field signal if the variation range does not exceed a threshold value;

[0033] The second processing unit is configured to perform the redo AGC operation and the estimated DC operation using the remaining portion of the first target field signal if the variation range exceeds the threshold value.

[0034] Preferably, the device further comprises:

[0035] A determination unit is used to determine that the WiFi signal belongs to an 11g signal if the rate level is not equal to the specified rate, or the byte length is not equal to a multiple of a specified value, and not to perform a redo AGC operation and a DC estimation operation.

[0036] Preferably, the device further comprises:

[0037] A judging unit, configured to judge whether the WiFi signal belongs to the 11ac signal based on the signal characteristic when a second target field signal corresponding to a second time position in the demodulated WiFi signal is obtained; the second time position is a time position corresponding to a VHT-Sig2 field signal specified in the WiFi5 protocol;

[0038] a removing unit, configured to determine that the WiFi signal belongs to the 11ac signal, and after performing the DC estimation operation to obtain the DC component, remove the DC component from the WiFi signal;

[0039] The discarding unit is used to determine that the WiFi signal belongs to the 11g signal, and after obtaining the DC component, discard the DC component.

[0040] Preferably, the judging unit is specifically used for:

[0041] When the second target field signal corresponding to the second time position in the demodulated WiFi signal is obtained, determining whether the signal feature is consistent with the content of the VHT-Sig2 field signal specified in the WiFi5 protocol;

[0042] If yes, it is determined that the WiFi signal belongs to the 11ac signal;

[0043] If not, it is determined that the WiFi signal belongs to the 11g signal.

[0044] Preferably, the second processing unit is specifically used for:

[0045] performing the redo AGC operation using a remaining portion of the first target field signal;

[0046] The estimated DC operation is performed using a remaining portion of the first target field signal after the redo AGC operation is completed.

[0047] Based on a WiFi signal processing method and device provided by the above-mentioned embodiment of the present invention, a WiFi signal is received in real time and the WiFi signal is demodulated; when it is determined that the WiFi signal belongs to any one of the 11g signal and the 11ac signal, and the L-Sig field signal in the WiFi signal is demodulated to obtain the L-Sig field content, the rate level and the byte length of the frame load are obtained from the L-Sig field content; if the rate level is equal to the specified rate, and the byte length is equal to a multiple of the specified value, then when the first target field signal corresponding to the first time position in the WiFi signal is demodulated, the rate level and the byte length of the frame load are obtained using the L-Sig field content. The target energy is calculated based on the initial part of the first target field signal; the first time position is the time position corresponding to the VHT-STF field signal specified in the WiFi5 protocol; the variation range between the target energy and the reference energy is calculated; the reference energy is calculated using the Stf field signal when demodulating the Stf field signal in the WiFi signal; if the variation range does not exceed the threshold value, the remaining part of the first target field signal is used to estimate the DC operation; if the variation range exceeds the threshold value, the remaining part of the first target field signal is used to perform the redo AGC operation and the estimated DC operation. In this scheme, if the energy variation is large, the AGC is redone and the DC is estimated. If the energy variation is not large, the DC is estimated directly without redoing the AGC. Before the VHT-STF field signal ends, even an ordinary receiver can determine whether it is a 11ac signal or an 11g signal. For 11ac signals, the estimated DC can be used to eliminate DC. For 11g signals, DC is directly discarded. Even if the 11g signal is mistakenly redone for AGC, it is still very likely to be demodulated correctly due to the low signal rate, thereby achieving the purpose of timely redoing AGC and retaining enough time to estimate DC without increasing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0049] Figure 1 A flowchart of a method for processing WiFi signals disclosed in an embodiment of the present invention;

[0050] Figure 2 A schematic diagram of an 11g protocol PHY frame structure disclosed in an embodiment of the present invention;

[0051] Figure 3A schematic diagram of a 11ac protocol PHY frame structure disclosed in an embodiment of the present invention;

[0052] Figure 4 This is a structural diagram of a WiFi signal processing device disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0055] As can be seen from the background technology, in the prior art, one is to use the VHT-STF signal segment only to redo AGC, and to eliminate DC by notching, which will sacrifice the performance of high-throughput communication. Another is to improve the hardware processing speed and quickly distinguish 11g signals from 11ac signals, which is more costly.

[0056] It should be noted that WiFi technology started with 802.11g, or WiFi3, and entered WiFi4, also known as 802.11n, with the signal frame name HT (High-Throughput) frame, and then to WiFi5, also known as 802.11ac, with the signal frame name VHT (Very High-Throughput) frame. There are already WiFi6 and WiFi7 devices on the market, but they are all forward compatible, that is, WiFi7 devices also support WiFi3 / 4 / 5 / 6 protocols. Since WiFi devices are forward compatible, this means that the frame structure in the WiFi7 protocol is compatible with the WiFi field in the older protocol to a certain extent, so whether it is WiFi5 devices or WiFi6 / 7 devices or newer devices, they all face existing technical problems.

[0057] Therefore, an embodiment of the present invention discloses a method and device for processing WiFi signals. In this solution, if the energy change is large, AGC is redone and DC is estimated. If the energy change is not large, DC is estimated directly without redoing AGC. Before the VHT-STF field signal ends, even an ordinary receiver can determine whether it is an 11ac signal or an 11g signal. For 11ac signals, the estimated DC can be used to eliminate DC later. For 11g signals, DC is directly discarded. Even if the 11g signal is mistakenly redone by AGC, it still has a high probability of being demodulated correctly due to the low signal rate, thereby achieving the purpose of timely redoing AGC and retaining enough time to estimate DC without increasing costs.

[0058] like Figure 1 FIG. 1 is a flowchart of a method for processing a WiFi signal disclosed in an embodiment of the present invention, comprising the following steps:

[0059] Step S101: receiving WiFi signals in real time and demodulating the WiFi signals.

[0060] In step S101, a receiver receives a WiFi signal and demodulates the WiFi signal. During the demodulation process, the WiFi signal is demodulated in the order of receiving time.

[0061] Step S102: When it is determined that the WiFi signal belongs to any one of the 11g signal and the 11ac signal, and the L-Sig field signal in the WiFi signal is demodulated to obtain the L-Sig field content, the rate level and the byte length of the frame payload are obtained from the L-Sig field content.

[0062] like Figure 2 FIG. 1 is a schematic diagram of an 11g protocol PHY frame structure disclosed in an embodiment of the present invention.

[0063] In the physical layer frame structure of 802.11g (i.e. 11g signal) in the WiFi3 protocol, the signals are transmitted in chronological order (the left one is transmitted first). 802.11g consists of Stf and Ltf (Long Training Field), L-Sig (Legacy Signal, 802.11g signal domain) and Data domain.

[0064] like Figure 3 , which is a schematic diagram of a 11ac protocol PHY frame structure disclosed in an embodiment of the present invention.

[0065] In the physical layer frame structure of 802.11ac (i.e. 11ac signal) in the WiFi5 protocol, signals are transmitted in chronological order (the left one is transmitted first). 802.11ac consists of Stf, Ltf, L-Sig and VHT-Sig (VHT Signal, 802.11ac signal domain) and VHT-Stf (802.11ac short training domain) and other domains.

[0066] Among them, VHT-Sig is divided into two sections, VHT-Sig1 and VHT-Sig2, each of which is 4us.

[0067] In step S102, before the signal segment at the time position corresponding to the VHT-Sig2 field signal ends, the receiver already knows that the WiFi signal may be one of the 11g signal and the 11ac signal, and not other WiFi signals, and has demodulated the L-Sig field content.

[0068] It should be noted that, through the field signal before the signal segment at the time position corresponding to the VHT-Sig2 field signal, it can be identified whether the WiFi signal is one of the 11g signal and the 11ac signal, or other WiFi signals.

[0069] Step S103: If the rate level is equal to the specified rate and the byte length is equal to a multiple of the specified value, when demodulating the first target field signal corresponding to the first time position in the WiFi signal, the target energy is calculated using the initial part of the first target field signal.

[0070] Among them, the first time position is the time position corresponding to the VHT-STF field signal specified in the WiFi5 protocol.

[0071] In step S103, if the rate level is equal to the specified rate and the byte length is equal to a multiple of the specified value, it is impossible to determine whether the WiFi signal belongs to an 11g signal. At this time, the receiver only knows that the WiFi signal is one of the 11g signal and the 11ac signal.

[0072] In one embodiment, if the rate level is not equal to the specified rate, or the byte length is not equal to a multiple of the specified value, it is determined that the WiFi signal belongs to an 11g signal, the AGC operation and the estimated DC operation are not redone, and the process is terminated without performing subsequent steps.

[0073] In the specific implementation, a signal pre-screener is used to perform preliminary screening based on the rate level indicated in the L-Sig field content and the byte length of the frame payload. When the rate is not 6Mbps or the byte length is not a multiple of 3, according to the WiFi5 protocol, it is determined that the WiFi signal belongs to an 11g signal. In this case, AGC does not need to be redone and DC does not need to be estimated.

[0074] That is to say, the WiFi5 protocol stipulates that the rate level indicated in the L-Sig field content of the 11ac signal should be equal to 6Mbps, and the byte length of the frame payload should be equal to a multiple of 3. Therefore, when the rate is not 6Mbps or the byte length is not a multiple of 3, based on the WiFi5 protocol and the elimination method, it is determined that the WiFi signal belongs to the 11g signal, then there is no need to redo AGC and there is no need to estimate DC.

[0075] It should be noted that when the receiver detects the L-Sig field signal, it will obtain the byte length and rate level of the frame payload. Although the processing time is consumed in the comparison with the specified rate and the specified value, since the L-Sig field signal is located earlier, the processing time of the L-Sig field signal does not affect the subsequent redo AGC and estimated DC time.

[0076] In the specific implementation process of step S103, the energy fluctuation threshold determiner is used to calculate the energy using the initial part of the VHT-STF field signal (for example, the first 1us). However, it cannot be determined at this time that the WiFi signal belongs to 11ac, so the VHT-STF field signal may not exist in the WiFi signal. The energy fluctuation threshold determiner selects the signal segment at the time position corresponding to the VHT-STF field signal specified in the WiFi5 protocol to calculate the energy.

[0077] Step S104: Calculate the variation range between the target energy and the reference energy.

[0078] The reference energy is calculated using the Stf field signal when demodulating the Stf field signal in the WiFi signal.

[0079] It should be noted that all WiFi protocols specify a Stf field signal at the beginning of the signal, more specifically, an L-STF field signal. The 11ac signal includes two Stf field signals, namely the L-STF field signal and the VHT-STF field signal.

[0080] Therefore, at the beginning, WiFi signals of all protocols will use the L-STF field signal to adjust the AGC for the first time, and at this time, the L-STF field signal will be used to calculate the reference energy.

[0081] In the specific implementation process of step S104, the energy fluctuation threshold determiner is used to calculate the difference between the target energy and the reference energy to obtain the variation range.

[0082] Step S105: Determine whether the variation range exceeds the threshold value; if not, execute step S106; if so, execute step S107.

[0083] The threshold value is set according to actual needs.

[0084] Step S106: performing an estimated DC operation using the remaining portion of the first target field signal.

[0085] Among them, the estimated DC operation is to identify and calculate the DC component in the WiFi signal so that this DC component can be removed in subsequent processing to improve the processing quality of the signal.

[0086] It should be noted that redoing the AGC operation is to use the energy of the STF to adjust the gain of the variable analog amplifier so that the signal energy entering the analog-to-digital converter is moderate. Therefore, if the variation range does not exceed the threshold value, it means that the signal energy is moderate. Regardless of whether the WiFi signal belongs to an 11g signal or an 11ac signal, there is no need to redo the AGC operation. Only the DC estimation operation needs to be performed. In subsequent judgments, if it is determined that the WiFi signal belongs to an 11g signal, the DC component obtained by the estimated DC operation can be directly discarded; if it is determined that the WiFi signal belongs to an 11ac signal, the DC component is removed from the WiFi signal.

[0087] Step S107: using the remaining portion of the first target field signal to perform redo AGC operation and estimate DC operation.

[0088] In the specific implementation process of step S107, the remaining part of the first target field signal is used to perform the redo AGC operation; and the remaining part of the first target field signal after the redo AGC operation is completed is used to perform the estimated DC operation.

[0089] It should be noted that the WiFi5 protocol only specifies one DC (Direct Current) subcarrier with a bandwidth of 312.5kHz for a bandwidth of 20MHz. If the notch method is used to remove DC, then in the case of frequency deviation (the maximum frequency deviation can reach about 240kHz), the signal will be seriously damaged, affecting the performance of high-throughput communication. Therefore, the VHT-STF field signal (4us in total) set by the protocol for re-doing AGC is used, that is, a part is used to re-do AGC, and the remaining part is used for DC estimation, and then the estimated DC is used to eliminate the DC in the signal, avoiding the use of a DC notch filter and not damaging the signal. In this way, when the DC estimation is more accurate, the performance of the device in high-throughput communication can be significantly improved.

[0090] The time length of the first target field signal is 4us. Assuming that the delay from the antenna port to the receiver processing point is 0.5us, the target energy consumption is calculated to be 1us. The calculated target energy is part of the redo AGC. The target energy is then used to complete all operations of the redo AGC. On the basis of 1us, it only takes 0.2us, that is, the redo AGC consumes a total of 1.2us, so there are 2.3us left for estimating DC, which is enough to complete the estimated DC operation.

[0091] It should be noted that the AGC operation needs to be redone due to the large fluctuation of signal energy. For 11ac signals, AGC redone operation and DC estimation operation should be performed. For 11g signals, because 11g does not support beamforming technology, the signal energy will not produce changes caused by beamforming, but only random jitter, which is usually small, so the fluctuation range will not exceed the threshold value. Even if there is a large jitter with a low probability, the fluctuation range exceeds the threshold value, causing the 11g signal to be mistakenly redone AGC and DC estimation, but because the signal rate level is the lowest 6Mbps at this time, the signal EVM (Error Vector Magnitude) requirement is also very low, so even if AGC is redone, there is still a high probability of correct demodulation, and the DC component obtained by the estimated DC operation can be discarded.

[0092] In one embodiment, before the VHT-STF field signal ends, even a receiver with a normal processing speed can determine whether the WiFi signal is a 11ac signal or a 11g signal, as follows:

[0093] When the signal characteristics are obtained by demodulating the second target field signal corresponding to the second time position in the WiFi signal, it is determined whether the WiFi signal belongs to the 11ac signal based on the signal characteristics; the second time position is the time position corresponding to the VHT-Sig2 field signal specified in the WiFi5 protocol.

[0094] If so, after performing the estimated DC operation to obtain the DC component, the DC component is removed from the WiFi signal; if not, it is determined that the WiFi signal belongs to an 11g signal, and after obtaining the DC component, the DC component is discarded.

[0095] It is understandable that the process of determining whether the WiFi signal is a 11ac signal or a 11g signal begins when the signal characteristics are obtained, and the determination can be completed before step S106 or step S107 is completed.

[0096] Preferably, judging whether the WiFi signal is a 11ac signal based on the signal characteristics includes:

[0097] Determine whether the signal characteristics are consistent with the target signal characteristics of the VHT-Sig2 field signal specified in the WiFi5 protocol; if so, determine that the WiFi signal belongs to the 11ac signal; if not, determine that the WiFi signal belongs to the 11g signal.

[0098] It should be noted that the second target field signal, i.e., the field signal at the time position corresponding to the VHT-Sig2 field signal, has a total of 4us, but only the subsequent 3.2us is used. If the WiFi signal belongs to the 11ac signal, there is a VHT-Sig2 field signal. Therefore, there is an obvious difference between the field signal at the time position corresponding to the VHT-Sig2 field signal and the VHT-Sig2 field signal in the frequency domain, and it can be determined whether it is an 11g signal or a 11ac signal.

[0099] Based on the above-mentioned method for processing WiFi signals disclosed in the embodiment of the present invention, in this solution, if the energy change is large, AGC is redone and DC is estimated. If the energy change is not large, there is no need to redo AGC and DC is directly estimated. Before the VHT-STF field signal ends, even an ordinary receiver can determine whether it is a 11ac signal or a 11g signal. For 11ac signals, the estimated DC can be used to eliminate DC later, and for 11g signals, DC is directly discarded. Even if the 11g signal is mistakenly redone by AGC, due to the low signal rate, there is still a high probability of correct demodulation, thereby achieving the purpose of timely redoing AGC and retaining enough time to estimate DC without increasing costs.

[0100] Corresponding to the method for processing WiFi signals disclosed in the above embodiment of the present invention, as Figure 4 , which is a structural diagram of a WiFi signal processing device disclosed in an embodiment of the present invention, including: a demodulation unit 401, an acquisition unit 402, an energy calculation unit 403, a variation range calculation unit 404, a first processing unit 405 and a second processing unit 406.

[0101] The demodulation unit 401 is used to receive WiFi signals in real time and demodulate the WiFi signals.

[0102] The acquisition unit 402 is used to acquire the rate level and the byte length of the frame payload from the L-Sig field content when it is determined that the WiFi signal belongs to any one of the 11g signal and the 11ac signal and the L-Sig field signal in the WiFi signal is demodulated to obtain the L-Sig field content.

[0103] The energy calculation unit 403 is used to calculate the target energy using the initial part of the first target field signal when starting to demodulate the first target field signal corresponding to the first time position in the WiFi signal if the rate level is equal to the specified rate and the byte length is equal to a multiple of the specified value; the first time position is the time position corresponding to the VHT-STF field signal specified in the WiFi5 protocol.

[0104] The variation range calculation unit 404 is used to calculate the variation range between the target energy and the reference energy; the reference energy is calculated using the Stf field signal when demodulating the Stf field signal in the WiFi signal.

[0105] The first processing unit 405 is configured to perform a DC estimation operation using the remaining portion of the first target field signal if the variation range does not exceed the threshold value.

[0106] The second processing unit 406 is configured to use the remaining portion of the first target field signal to perform a redo AGC operation and estimate a DC operation if the variation range exceeds the threshold value.

[0107] In one embodiment, the second processing unit 406 is specifically configured to:

[0108] The redo AGC operation is performed using the remaining portion of the first target field signal; and the estimated DC operation is performed using the remaining portion of the first target field signal after the redo AGC operation is completed.

[0109] In one embodiment, the device further comprises:

[0110] The determination unit is used to determine that the WiFi signal belongs to an 11g signal if the rate level is not equal to the specified rate, or the byte length is not equal to a multiple of the specified value, and does not perform the redo AGC operation and the estimated DC operation.

[0111] In one embodiment, the device further comprises:

[0112] A judging unit, configured to judge whether the WiFi signal belongs to a 11ac signal based on the signal characteristics when a signal characteristic is obtained by demodulating a second target field signal corresponding to a second time position in the WiFi signal; the second time position is a time position corresponding to a VHT-Sig2 field signal specified in the WiFi5 protocol;

[0113] A removal unit, used for determining that the WiFi signal belongs to an 11ac signal, and removing the DC component from the WiFi signal after performing a DC estimation operation to obtain the DC component;

[0114] The discarding unit is used to determine whether the WiFi signal belongs to an 11g signal and discard the DC component after obtaining the DC component.

[0115] In one embodiment, the judging unit is specifically configured to:

[0116] When the signal characteristic of the second target field signal corresponding to the second time position in the demodulated WiFi signal is obtained, determining whether the signal characteristic is consistent with the target signal characteristic of the VHT-Sig2 field signal specified in the WiFi5 protocol;

[0117] If yes, it is determined that the WiFi signal is an 11ac signal;

[0118] If not, it is determined that the WiFi signal is an 11g signal.

[0119] Based on the above-mentioned embodiment of the present invention, a WiFi signal processing device is disclosed. In this solution, if the energy change is large, AGC is redone and DC is estimated. If the energy change is not large, DC is estimated directly without redoing AGC. Before the VHT-STF field signal ends, even an ordinary receiver can determine whether it is an 11ac signal or an 11g signal. For 11ac signals, the estimated DC can be used to eliminate DC later. For 11g signals, DC is directly discarded. Even if the 11g signal is mistakenly redone by AGC, it is still very likely to be demodulated correctly due to the low signal rate, thereby achieving the purpose of timely redoing AGC and retaining enough time to estimate DC without increasing costs.

[0120] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein 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, they may be located in one place, or they 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 scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0121] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0122] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for processing WiFi signals, characterized in that: The method comprises: Receive WiFi signals in real time and demodulate the WiFi signals; When it is determined that the WiFi signal belongs to any one of a 11g signal and a 11ac signal, and an L-Sig field signal in the WiFi signal is demodulated to obtain L-Sig field content, acquiring a rate level and a byte length of a frame payload from the L-Sig field content; If the rate level is equal to the specified rate and the byte length is equal to a multiple of the specified value, then when demodulating the first target field signal corresponding to the first time position in the WiFi signal, the target energy is calculated using the initial part of the first target field signal; the first time position is the time position corresponding to the VHT-STF field signal specified in the WiFi5 protocol; Calculating a variation range between the target energy and the reference energy; the reference energy is calculated using the Stf field signal when demodulating the Stf field signal in the WiFi signal; If the variation range does not exceed the threshold value, using the remaining part of the first target field signal to perform an estimated DC operation; If the variation range exceeds the threshold value, the redo AGC operation and the estimated DC operation are performed using the remaining portion of the first target field signal.

2. The method according to claim 1, characterized in that The method further comprises: If the rate level is not equal to the specified rate, or the byte length is not equal to a multiple of a specified value, it is determined that the WiFi signal belongs to an 11g signal, and the AGC operation and the estimated DC operation are not performed.

3. The method according to claim 1, characterized in that The method further comprises: When a signal characteristic is obtained by demodulating a second target field signal corresponding to a second time position in the WiFi signal, determining whether the WiFi signal belongs to the 11ac signal based on the signal characteristic; the second time position is a time position corresponding to a VHT-Sig2 field signal specified in the WiFi5 protocol; If so, after performing the estimated DC operation to obtain the DC component, removing the DC component from the WiFi signal; If not, it is determined that the WiFi signal belongs to the 11g signal, and after obtaining the DC component, the DC component is discarded.

4. The method according to claim 3, characterized in that The method of obtaining a signal characteristic by demodulating the second target field signal corresponding to the second time position in the WiFi signal and determining whether the WiFi signal belongs to the 11ac signal based on the signal characteristic comprises: When a signal characteristic is obtained by demodulating the second target field signal corresponding to the second time position in the WiFi signal, determining whether the signal characteristic is consistent with a target signal characteristic of the VHT-Sig2 field signal specified in the WiFi5 protocol; If yes, it is determined that the WiFi signal belongs to the 11ac signal; If not, it is determined that the WiFi signal belongs to the 11g signal.

5. The method according to any one of claims 1 to 4, characterized in that: The redoing AGC operation and the estimating DC operation using the remaining portion of the first target field signal include: performing the redo AGC operation using a remaining portion of the first target field signal; The estimated DC operation is performed using a remaining portion of the first target field signal after the redo AGC operation is completed.

6. A WiFi signal processing device, characterized in that: The device comprises: A demodulation unit, used to receive WiFi signals in real time and demodulate the WiFi signals; an acquiring unit, configured to acquire a rate level and a byte length of a frame payload from the L-Sig field content when it is determined that the WiFi signal belongs to any one of a 11g signal and a 11ac signal and an L-Sig field signal in the WiFi signal is demodulated to obtain L-Sig field content; an energy calculation unit, configured to calculate a target energy using an initial portion of a first target field signal corresponding to a first time position in a WiFi signal when demodulating the first target field signal corresponding to a first time position in the WiFi signal if the rate level is equal to a specified rate and the byte length is equal to a multiple of a specified value; the first time position is a time position corresponding to a VHT-STF field signal specified in the WiFi5 protocol; A variation range calculation unit, used to calculate the variation range between the target energy and the reference energy; the reference energy is calculated using the Stf field signal when demodulating the Stf field signal in the WiFi signal; a first processing unit, configured to perform an estimated DC operation using a remaining portion of the first target field signal if the variation range does not exceed a threshold value; The second processing unit is configured to perform the redo AGC operation and the estimated DC operation using the remaining portion of the first target field signal if the variation range exceeds the threshold value.

7. The device according to claim 6, characterized in that The device also includes: A determination unit is used to determine that the WiFi signal belongs to an 11g signal if the rate level is not equal to the specified rate, or the byte length is not equal to a multiple of a specified value, and not to perform a redo AGC operation and a DC estimation operation.

8. The device according to claim 6, characterized in that The device also includes: A judging unit, configured to judge whether the WiFi signal belongs to the 11ac signal based on the signal characteristic when a second target field signal corresponding to a second time position in the demodulated WiFi signal is obtained; the second time position is a time position corresponding to a VHT-Sig2 field signal specified in the WiFi5 protocol; a removing unit, configured to determine that the WiFi signal belongs to the 11ac signal, and after performing the DC estimation operation to obtain the DC component, remove the DC component from the WiFi signal; The discarding unit is used to determine that the WiFi signal belongs to the 11g signal, and after obtaining the DC component, discard the DC component.

9. The device according to claim 8, characterized in that The judging unit is specifically used for: When the second target field signal corresponding to the second time position in the demodulated WiFi signal is obtained, determining whether the signal feature is consistent with the content of the VHT-Sig2 field signal specified in the WiFi5 protocol; If yes, it is determined that the WiFi signal belongs to the 11ac signal; If not, it is determined that the WiFi signal belongs to the 11g signal.

10. The device according to any one of claims 6 to 9, characterized in that: The second processing unit is specifically configured to: performing the redo AGC operation using a remaining portion of the first target field signal; The estimated DC operation is performed using a remaining portion of the first target field signal after the redo AGC operation is completed.

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