Synchronization method for resisting multi-antenna CSD, related device and storage medium

Abstract

The invention provides a synchronization method for resisting multi-antenna CSD, a related device and a storage medium, and the method comprises the steps: determining an initial synchronization point according to a locally stored long training field of a traditional part if a currently received signal is a traditional part signal and is not a high signal-to-noise ratio signal; if the currently received signal is a long training field signal of a non-traditional part and is not a high signal-to-noise ratio signal and is sent in a non-beamforming manner, determining a secondary synchronization point according to a locally stored long training field of the non-traditional part; and finally, according to the initial synchronization point and the secondary synchronization point, determining a final synchronization point, and through the final synchronization point, helping the receiver to reduce the CSD influence in the process of finding the first path under the condition that the receiver receives a signal with a non-high signal-to-noise ratio and synchronizes by using a mode that the received signal is related to a local storage signal. Therefore, the receiver is helped to obtain better synchronization performance and demodulation performance.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a synchronization method, related apparatus, and storage medium for countering multi-antenna CSD. Background Technology

[0002] Since Wi-Fi 4 and later protocols introduced Cyclic Shift Diversity (CSD) transmission technology, the challenge of receiver synchronization has increased. Specifically, synchronization typically involves two methods: autocorrelation between the received signal and the L-STF (Legacy Short Training Field) and L-LTF (Legacy Long Training Field) portions of the legacy signal, and correlation between the received signal and the locally stored L-LTF signal. The former is unaffected by CSD but has weaker noise immunity and is more prone to larger synchronization errors at medium to low signal-to-noise ratios (SNRs). The latter, because the locally stored signal is noise-free, performs better and has smaller errors at medium to low SNRs. Therefore, for high SNR signals, autocorrelation of the received signal is typically used for synchronization to combat CSD. For medium to low SNR signals, correlation between the received signal and the locally stored signal is typically used for synchronization; however, this method is susceptible to CSD interference, making it difficult to find the first path during synchronization, resulting in synchronization errors and affecting reception performance. Summary of the Invention

[0003] In view of this, the present invention provides a synchronization method, related apparatus and storage medium to combat multi-antenna CSD, which helps the receiver to be unaffected by CSD during the first path finding process when receiving signals that are not of high signal-to-noise ratio, even when using a method of synchronizing the received signal with the locally stored signal, thereby helping the receiver to obtain better synchronization and demodulation performance.

[0004] The first aspect of this invention provides a synchronization method for countering multi-antenna CSD, comprising:

[0005] Real-time signal reception;

[0006] If the currently received signal is a traditional part signal and is not a high signal-to-noise ratio signal, then the initial synchronization point is determined based on the long training field of the traditional part stored locally.

[0007] If the currently received signal is a long training field signal of the non-traditional part, and is not a high signal-to-noise ratio signal and is transmitted without beamforming, then the secondary synchronization point is determined based on the long training field of the non-traditional part stored locally.

[0008] The final synchronization point is determined based on the initial synchronization point and the secondary synchronization point.

[0009] Optionally, the synchronization method against multi-antenna CSD further includes:

[0010] If the currently received signal is the traditional part of the signal and is a high signal-to-noise ratio signal, then the initial synchronization point is determined based on the long training field of the traditional part of the currently received signal.

[0011] Set the secondary synchronization point as the initial synchronization point.

[0012] Optionally, if the currently received signal is a traditional portion of the signal and is a high signal-to-noise ratio signal, then determining the initial synchronization point based on the long training field of the traditional portion of the currently received signal includes:

[0013] If the currently received signal is the traditional part of the signal and is a high signal-to-noise ratio signal, then the long training field of the traditional part of the currently received signal is used to perform sliding correlation summation to obtain the first sliding correlation value;

[0014] The data point after which the increment of the first sliding correlation value is less than the first threshold value twice consecutively is taken as the initial synchronization point.

[0015] Optionally, the synchronization method against multi-antenna CSD further includes:

[0016] If the currently received signal is a long training field signal that is not part of the traditional signal and is a high signal-to-noise ratio signal or a beamforming transmission, then the secondary synchronization point is set as the initial synchronization point.

[0017] Optionally, if the currently received signal is a traditional portion signal and not a high signal-to-noise ratio signal, then determining the initial synchronization point based on the long training field of the traditional portion stored locally includes:

[0018] If the currently received signal is the traditional part of the signal and is not a high signal-to-noise ratio signal, then the long training field of the traditional part stored locally is used to perform sliding correlation summation to obtain the second sliding correlation value;

[0019] The correlation point where the second sliding correlation value, which is initially greater than the second threshold value, is located is taken as the initial synchronization point.

[0020] Optionally, if the currently received signal is a long training field signal of the non-traditional part, and is not a high signal-to-noise ratio signal while being transmitted without beamforming, then determining the secondary synchronization point based on the locally stored long training field of the non-traditional part includes:

[0021] If the currently received signal is a long training field signal of the non-traditional part, and is not a high signal-to-noise ratio signal and is transmitted without beamforming, then the long training field of the non-traditional part stored locally is used to perform sliding correlation summation to obtain the third sliding correlation value.

[0022] The correlation point where the third sliding correlation value, which is initially greater than the third threshold, is located is taken as the target correlation point;

[0023] The relevant points corresponding to the time difference between the target relevant point and the target time interval are used as secondary synchronization points; wherein, the target time interval is the time interval between the long training field of the traditional part and the long training field of the non-traditional part.

[0024] Optionally, determining the final synchronization point based on the initial synchronization point and the secondary synchronization point includes:

[0025] Determine whether the difference between the secondary synchronization point and the initial synchronization point is greater than a threshold.

[0026] If it is determined that the difference between the secondary synchronization point and the initial synchronization point is greater than a threshold, the initial synchronization point is adjusted backward by a target duration to obtain the final synchronization point; wherein, the target duration is determined based on the cyclic shift time of the long training field in the traditional part;

[0027] If it is determined that the difference between the secondary synchronization point and the initial synchronization point is not greater than a threshold, the initial synchronization point is taken as the final synchronization point.

[0028] A second aspect of the present invention provides a synchronization device for countering multi-antenna CSD, comprising:

[0029] A signal receiving unit is used to receive signals in real time.

[0030] The initial synchronization point determination unit is used to determine the initial synchronization point based on the long training field of the traditional part stored locally if the currently received signal is a traditional part signal and is not a high signal-to-noise ratio signal.

[0031] The secondary synchronization point determination unit is used to determine the secondary synchronization point based on the long training field of the non-traditional part if the currently received signal is a long training field signal of the non-traditional part and is not a high signal-to-noise ratio signal and is transmitted without beamforming.

[0032] The final synchronization point determination unit is used to determine the final synchronization point based on the initial synchronization point and the secondary synchronization point.

[0033] Optionally, the synchronization device for countering multi-antenna CSD further includes:

[0034] The initial synchronization point determination unit is further configured to determine the initial synchronization point based on the long training field of the traditional part of the currently received signal if the currently received signal is a traditional part signal and is a high signal-to-noise ratio signal.

[0035] The secondary synchronization point determination unit is also used to set the secondary synchronization point as the initial synchronization point.

[0036] Optionally, the initial synchronization point determination unit includes:

[0037] The first sliding correlation unit is used to perform sliding correlation summation on the long training field of the traditional part of the currently received signal if the currently received signal is the traditional part signal and is a high signal-to-noise ratio signal, so as to obtain the first sliding correlation value.

[0038] The first initial synchronization point determination sub-unit is used to take the data point after the first sliding correlation value increment is less than the first threshold value twice consecutively as the initial synchronization point.

[0039] Optionally, the synchronization device for countering multi-antenna CSD further includes:

[0040] The secondary synchronization point determination unit is further configured to set the secondary synchronization point as the initial synchronization point if the currently received signal is a long training field signal of a non-traditional part, and is a high signal-to-noise ratio signal or a beamforming transmission.

[0041] Optionally, the initial synchronization point determination unit includes:

[0042] The second sliding correlation unit is used to perform sliding correlation summation using the long training field of the traditional part stored locally if the currently received signal is the traditional part signal and is not a high signal-to-noise ratio signal, in order to obtain the second sliding correlation value.

[0043] The second initial synchronization point determination sub-unit is used to take the correlation point where the second sliding correlation value, which is initially greater than the second threshold value, is located as the initial synchronization point.

[0044] Optionally, the secondary synchronization point determination unit includes:

[0045] The third sliding correlation unit is used to perform sliding correlation summation using the long training field of the non-traditional part stored locally if the currently received signal is a long training field signal of the non-traditional part and is not a high signal-to-noise ratio signal and is transmitted without beamforming, so as to obtain the third sliding correlation value.

[0046] The target correlation point determination unit is used to determine the correlation point where the third sliding correlation value, which is initially greater than the third threshold value, is located as the target correlation point.

[0047] The secondary synchronization point determination subunit is used to take the relevant points corresponding to the time difference between the target relevant point and the target time interval as secondary synchronization points; wherein, the target time interval is the time interval between the long training field of the traditional part and the long training field of the non-traditional part.

[0048] Optionally, the final synchronization point determination unit includes:

[0049] The judgment unit is used to determine whether the difference between the secondary synchronization point and the initial synchronization point is greater than a threshold.

[0050] The final synchronization point determination subunit is used to adjust the initial synchronization point backward by a target duration if the judgment unit determines that the difference between the secondary synchronization point and the initial synchronization point is greater than a threshold, so as to obtain the final synchronization point; wherein, the target duration is determined based on the cyclic shift time of the long training field in the traditional part.

[0051] The final synchronization point determination subunit is further configured to, if the judgment unit determines that the difference between the secondary synchronization point and the initial synchronization point is not greater than a threshold, use the initial synchronization point as the final synchronization point.

[0052] A third aspect of the present invention provides an electronic device, comprising:

[0053] One or more processors;

[0054] A storage device on which one or more programs are stored;

[0055] When the one or more programs are executed by the one or more processors, the one or more processors implement the synchronization method against multi-antenna CSD as described in any one of the first aspects.

[0056] A fourth aspect of the present invention provides a storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the synchronization method against multi-antenna CSD as described in any one of the first aspects.

[0057] As can be seen from the above scheme, the present invention provides a synchronization method, related device, and storage medium to combat multi-antenna CSD. If the currently received signal is a conventional part signal and is not a high signal-to-noise ratio signal, the initial synchronization point is determined based on the long training field of the conventional part stored locally. If the currently received signal is a non-conventional part long training field signal and is not a high signal-to-noise ratio signal while being transmitted without beamforming, the secondary synchronization point is determined based on the long training field of the non-conventional part stored locally. Finally, the final synchronization point is determined based on the initial synchronization point and the secondary synchronization point. The final synchronization point helps the receiver reduce the CSD impact during the first path finding process when receiving medium and low signal-to-noise ratio signals and using the correlation between the received signal and the locally stored signal for synchronization, thereby helping the receiver obtain better synchronization and demodulation performance. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0059] Figure 1 A schematic diagram of the 802.11g protocol PHY frame structure;

[0060] Figure 2 A flowchart illustrating a synchronization method for countering multi-antenna CSD provided in an embodiment of the present invention;

[0061] Figure 3 A flowchart of a method for determining an initial synchronization point is provided in another embodiment of the present invention;

[0062] Figure 4 A flowchart of a method for determining an initial synchronization point is provided in another embodiment of the present invention;

[0063] Figure 5 A flowchart of a method for determining a secondary synchronization point is provided in another embodiment of the present invention;

[0064] Figure 6 A flowchart of a method for determining the final synchronization point is provided in another embodiment of the present invention;

[0065] Figure 7 A flowchart illustrating a synchronization method for countering multi-antenna CSD, provided in another embodiment of the present invention;

[0066] Figure 8 A schematic diagram of a synchronization device for countering multi-antenna CSD provided in another embodiment of the present invention;

[0067] Figure 9 This is a schematic diagram of an electronic device for implementing a synchronization method against multi-antenna CSD, as provided in another embodiment of the present invention. Detailed Implementation

[0068] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0069] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0070] It should be noted that the concepts of "first" and "second" mentioned in this invention are only used to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0071] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0072] Currently, in existing technologies, all protocols from Wi-Fi 4 onwards, whether Wi-Fi 4, Wi-Fi 5, or Wi-Fi 6, share the same Legacy section at the beginning of their frame structures, including L-Stf, L-Ltf, and L-Sig (traditional beacon signal). Their physical layer frame structure is as follows: Figure 1 As shown, the signals are transmitted sequentially in chronological order (the one on the left is transmitted first). The same applies to protocols after Wi-Fi 6; this invention only uses Wi-Fi 4 / 5 / 6 as examples.

[0073] In existing technologies, when synchronizing by correlating the received signal with the locally stored signal, a sliding correlation is performed between the local L-Ltf and the received signal. The received L-Ltf signal is a superposition of L-Ltf signals transmitted by multiple transmit antennas. Taking four antennas as an example, named antennas 1, 2, 3, and 4 respectively, antenna 1 does not undergo CSD processing. Antennas 2, 3, and 4 require CSD processing of 50ns, 100ns, and 150ns respectively, according to the protocol. That is, the initial 50ns / 100ns / 150ns long signals are cyclically shifted to the end to form a signal of the same length; the new signal is simply a cyclic shift of the original signal. Therefore, during sliding correlation, the signal with 150ns CSD processing, when correlated with the local L-Ltf (without any cyclic shift), first generates a point where the correlation value exceeds the threshold. Since the receiver is unaware that the transmitter uses multiple antennas, it usually treats it as a single antenna and considers this point to be the correlation head, i.e., the synchronization point.

[0074] Of course, the receiver can also add some complex algorithms to counteract the impact of CSD when synchronizing with the received signal and the locally stored signal, but on the one hand, the processing is complex, and on the other hand, it can never make up for the loss caused by the receiver's lack of information about the number of transmitter antennas.

[0075] However, when the transmitter is not performing beamforming, the impact of CSD can be mitigated by leveraging the characteristics of the protocol. This is because, according to the protocol, the CSD value used by the transmitter when sending L-Ltf is different from the CSD value used when sending Wifi4 / 5 / 6-Ltf; the latter has a larger CSD value. For example, with four spacetime streams (the receiver learns the number of spacetime streams after receiving the Wifi4 / 5 / 6-Sig beacon signal), each antenna transmits one spacetime stream (a different signal). However, when transmitting Wifi4 / 5 / 6-Ltf, each antenna still transmits the same Ltf signal, but with different CSD processing applied. Antenna 1 does not receive CSD processing, while antennas 2, 3, and 4 require different CSD processing according to the protocol. Do not add 400ns, 200ns, or 600ns CSD processing. When the transmitter does not perform Beamforming transmission (the receiver will know this information after receiving the Wifi4 / 5 / 6-Sig beacon signal), the local Wifi4 / 5 / 6-Ltf signal can still generate a correlation value that significantly exceeds the threshold when sliding to the received Wifi4 / 5 / 6-Ltf signal. This value is ultimately judged as a false lead point, which is earlier than the lead point found by the normally transmitted antenna signal, resulting in lead point positioning error and damaging receiver performance.

[0076] To address the problems in the prior art, embodiments of the present invention provide a synchronization method to counter multi-antenna CSD, such as... Figure 2 As shown, the specific steps include:

[0077] S201, Real-time signal reception.

[0078] S202. If the currently received signal is a traditional part signal and is not a high signal-to-noise ratio signal, then determine the initial synchronization point based on the long training field of the traditional part stored locally.

[0079] The legacy signal includes L-Stf, L-Ltf, and L-Sig.

[0080] It should be noted that the methods for determining whether a signal is a traditional signal can include, but are not limited to, analyzing the signal modulation method, frame structure, etc., to confirm whether it is a Legacy signal; no limitation is made here.

[0081] In the practical application of this invention, a signal-to-noise ratio (SNR) threshold can be preset. The SNR of the currently received signal is compared with this SNR threshold. If it is lower than the threshold, it is determined that it is not a high SNR signal, i.e., a medium or low SNR signal; otherwise, it is considered a high SNR signal.

[0082] The signal-to-noise ratio threshold is set and modified in advance by experts and relevant authorized technical personnel, and is not limited here.

[0083] Optionally, in another embodiment of the present invention, if the currently received signal is a traditional part signal and is a high signal-to-noise ratio signal, the initial synchronization point is determined based on the long training field of the traditional part of the currently received signal; and the secondary synchronization point is set as the initial synchronization point.

[0084] In the practical application of this invention, if the currently received signal is a traditional portion of the signal and has a high signal-to-noise ratio, one implementation method for determining the initial synchronization point based on the long training field of the traditional portion of the currently received signal is as follows: Figure 3 As shown, it includes:

[0085] S301. If the currently received signal is the traditional part of the signal and is a high signal-to-noise ratio signal, the sliding correlation summation is performed using the long training field of the traditional part of the currently received signal to obtain the first sliding correlation value.

[0086] In the practical application of this invention, the periodicity of L-Stf can be utilized to perform sliding correlation on the signal sequence at intervals of one period, that is, summing after conjugate multiplication. During the process of sliding correlation summation, the sum of the sliding correlation will increase from small to large as the L-Stf signal arrives and remain at this size until the L-Stf signal ends and then gradually decreases again. The inflection point where the correlation sum increases from small to large until it no longer increases is the synchronization point.

[0087] Understandably, this inflection point is prone to significant errors due to noise interference, and therefore is generally suitable for situations with a high signal-to-noise ratio.

[0088] S302, take the data point after the first sliding correlation value increment is less than the first threshold value twice in a row as the initial synchronization point.

[0089] The first threshold value is set and modified in advance by experts and relevant authorized technical personnel, and is not limited here.

[0090] For example: if the first sliding correlation value increment sequence is [3, 1, 0.5, 0.3, 0.2], and the first threshold value is 1, then:

[0091] The third increment of 0.5 and the fourth increment of 0.3 are both less than the first threshold. The data point after the fourth increment (i.e. the fifth data point) is set as the initial synchronization point.

[0092] The present invention ensures that the synchronization point is at the beginning of the data stability period through the above method, avoiding misjudgment due to a single fluctuation.

[0093] Optionally, in another embodiment of the present invention, one implementation of step S202 is as follows: Figure 4 As shown, it specifically includes:

[0094] S401. If the currently received signal is a traditional part signal and is not a high signal-to-noise ratio signal, perform sliding correlation summation using the long training field of the traditional part stored locally to obtain the second sliding correlation value.

[0095] It should be noted that the specific implementation of the sliding correlation summation in this step can be found in step S301, and will not be repeated here.

[0096] S402, take the correlation point where the second sliding correlation value is initially greater than the second threshold value as the initial synchronization point.

[0097] The second threshold value is set and modified in advance by experts and relevant authorized technical personnel, and is not limited here.

[0098] S203. If the currently received signal is a long training field signal of the non-traditional part, and is not a high signal-to-noise ratio signal and is transmitted without beamforming, then determine the secondary synchronization point based on the long training field of the non-traditional part stored locally.

[0099] Among them, the non-traditional signals include Wifi4 / 5 / 6-Stf (Short Training Field), Wifi4 / 5 / 6-Ltf (Long Training Field), and Wifi4 / 5 / 6-Sig (Beacon Signal).

[0100] It should be noted that the same applies to protocols after Wi-Fi 6; this invention only uses Wi-Fi 4 / 5 / 6 as examples for explanation.

[0101] In the practical application of this invention, it can be determined whether it is beamforming transmission by checking the beamforming flag output by the demodulator, but this is not limited to that.

[0102] Optionally, in another embodiment of the present invention, if the currently received signal is a long training field signal of a non-traditional part, and is a high signal-to-noise ratio signal or a beamforming transmission, then the secondary synchronization point is set as the initial synchronization point.

[0103] Optionally, in another embodiment of the present invention, one implementation of step S203 is as follows: Figure 5 As shown, it specifically includes:

[0104] S501. If the currently received signal is a long training field signal of the non-traditional part, and is not a high signal-to-noise ratio signal and is transmitted without beamforming, then the long training field of the non-traditional part stored locally is used to perform sliding correlation summation to obtain the third sliding correlation value.

[0105] It should be noted that the specific implementation of the sliding correlation summation in this step can be found in step S301, and will not be repeated here.

[0106] S502, take the correlation point where the third sliding correlation value is first greater than the third threshold value as the target correlation point.

[0107] The third threshold value is set and modified in advance by experts and relevant authorized technical personnel, and is not limited here.

[0108] S503. Use the time difference between the target's relevant point and the target's time interval as the secondary synchronization point.

[0109] The target time interval is the time interval between the long training field of the traditional part and the long training field of the non-traditional part.

[0110] S204. Determine the final synchronization point based on the initial synchronization point and the secondary synchronization point.

[0111] Understandably, if there is no CSD during single-antenna transmission, the initial synchronization point and the secondary synchronization point are consistent. However, considering related errors, there may be differences, but these are usually small, within 25ns. According to the protocol, as long as there are multiple antennas transmitting, Legacy is handled by CSD. Even if Wifi4 / 5 / 6-Ltf transmits only one spacetime stream, the secondary synchronization point will be 150ns later than the initial synchronization point. If Wifi4 / 5 / 6-Ltf transmits multiple spacetime streams, the secondary synchronization point will be at least 200ns earlier than the initial synchronization point.

[0112] Optionally, in another embodiment of the present invention, one implementation of step S204 is as follows: Figure 6 As shown, it includes:

[0113] S601. Determine whether the difference between the secondary synchronization point and the initial synchronization point is greater than the threshold.

[0114] The threshold can be 100ns, and no limit is specified here.

[0115] Continuing with the above example, when the difference between the secondary synchronization point and the initial synchronization point is greater than 100ns, the L-Ltf must have undergone CSD processing, so the initial synchronization point needs to be adjusted to obtain the final synchronization point; when the difference between the two synchronization points is less than 100ns, either the transmitter has performed beamforming transmission, or the transmitter only has one transmitting antenna, so the initial synchronization point can be directly used as the final synchronization point.

[0116] Specifically, if it is determined that the difference between the secondary synchronization point and the initial synchronization point is greater than the threshold, then step S602 is executed; if it is determined that the difference between the secondary synchronization point and the initial synchronization point is not greater than the threshold, then step S603 is executed.

[0117] S602. Adjust the target duration backward from the initial synchronization point to obtain the final synchronization point.

[0118] The target duration is determined based on the cyclic shift time of the long training field in the traditional part.

[0119] Continuing with the above example, according to the protocol, regardless of the number of antennas (except for single antennas), the maximum CSD processing value for L-Ltf is 150ns, 175ns, or 200ns, which is not limited here.

[0120] Understandably, the larger the CSD processing value, the more the signal is staggered in time, and the stronger the anti-interference capability. However, it cannot be infinitely large. Therefore, the current protocol specifies several levels such as 150ns, 175ns, or 200ns in order to achieve a balance between performance and complexity.

[0121] In the actual application of this invention, the initial synchronization point can be adjusted backward by 175ns to obtain the final synchronization point, which is then output to the demodulator. No limitation is made here.

[0122] S603, Use the initial synchronization point as the final synchronization point.

[0123] It should be noted that this invention does not limit the use of existing enhancement algorithms to combat CSD when finding the initial and secondary synchronization points. This can improve the synchronization performance of the Legacy section, and can also improve the synchronization performance of the signal after Legacy when the transmitter performs Beamforming or when the transmitter has only one transmit antenna. When the transmitter does not perform Beamforming and has multiple transmit antennas, this patent can still be used to further optimize the synchronization point to combat the impact of multi-antenna CSD. This invention is not limited here.

[0124] like Figure 7 The diagram shows the overall flowchart of a synchronization method against multi-antenna CSD provided by an embodiment of the present invention. After receiving a signal, it is first determined whether it is a Legacy signal. If it is a Legacy signal, it is then determined whether it is a high signal-to-noise ratio (SNR) signal. If it is a high SNR signal, the autocorrelation synchronizer 0 can be activated to synchronize the signal using the autocorrelation between the preceding and following signals. This method is naturally immune to CSD. The initial synchronization point is output to the synchronization position adjuster, and the secondary synchronization point is directly set as the initial synchronization point. If it is not a high SNR signal, the local correlation synchronizer 1 is activated to perform sliding correlation using the locally stored L-Ltf. A threshold is preset, and the first correlation point with a correlation value higher than this threshold is found and set as the initial synchronization point.

[0125] If the signal is not a Legacy signal, determine whether it is receiving Wifi4 / 5 / 6-Ltf. If so, check the Beamforming flag output by the demodulator and determine whether it is a high signal-to-noise ratio signal. If it is a high signal-to-noise ratio signal or a Beamforming signal, there is no need to start the local correlation synchronizer 2. Directly set the secondary synchronization point as the initial synchronization point and output it to the synchronization position adjuster. Otherwise, start the local correlation synchronizer 2, use the locally stored Wifi4 / 5 / 6-Ltf to perform sliding correlation, and pre-set a threshold. Find the first correlation point with a correlation value higher than this threshold. Subtract a fixed value (the time interval from L-Ltf to Wifi4 / 5 / 6-Ltf) from this point in time and set it as the secondary synchronization point. Output it to the synchronization position adjuster.

[0126] After obtaining the information of the initial synchronization point and the secondary synchronization point, the synchronization position adjuster determines the time difference between the two points and determines the final synchronization point based on the initial synchronization point and the secondary synchronization point, and outputs it to the adjuster.

[0127] It is understood that in the actual application of this invention, only one local coordinator can be set up to store both L-Ltf and Wifi4 / 5 / 6-Ltf, and this is not limited here.

[0128] As can be seen from the above scheme, the present invention provides a synchronization method to counteract CSD of multiple antennas. If the currently received signal is a traditional part signal and is not a high signal-to-noise ratio signal, the initial synchronization point is determined based on the long training field of the traditional part stored locally. If the currently received signal is a long training field signal of the non-traditional part and is not a high signal-to-noise ratio signal and is transmitted without beamforming, the secondary synchronization point is determined based on the long training field of the non-traditional part stored locally. Finally, the final synchronization point is determined based on the initial synchronization point and the secondary synchronization point. The final synchronization point helps the receiver reduce the CSD impact during the first path finding process when synchronizing with the received signal in a way that correlates with the locally stored signal, even when receiving a non-high signal-to-noise ratio signal, thereby helping the receiver obtain better synchronization and demodulation performance.

[0129] Another embodiment of the present invention provides a synchronization device for countering multi-antenna CSD, such as Figure 8 As shown, it specifically includes:

[0130] The signal receiving unit 801 is used to receive signals in real time.

[0131] The initial synchronization point determination unit 802 is used to determine the initial synchronization point based on the long training field of the traditional part stored locally if the currently received signal is a traditional part signal and is not a high signal-to-noise ratio signal.

[0132] The secondary synchronization point determination unit 803 is used to determine the secondary synchronization point based on the long training field of the non-traditional part if the currently received signal is a long training field signal of the non-traditional part and is not a high signal-to-noise ratio signal and is transmitted without beamforming.

[0133] The final synchronization point determination unit 804 is used to determine the final synchronization point based on the initial synchronization point and the secondary synchronization point.

[0134] For details on the specific operation of the units disclosed in the above embodiments of the present invention, please refer to the corresponding method embodiments, such as... Figure 2 As shown, it will not be elaborated further here.

[0135] Optionally, in another embodiment of the present invention, the initial synchronization point determination unit 802 is further configured to determine the initial synchronization point based on the long training field of the traditional part of the currently received signal if the currently received signal is a traditional part signal and is a high signal-to-noise ratio signal.

[0136] The specific working process of the units disclosed in the above embodiments of the present invention can be found in the corresponding method embodiments, and will not be repeated here.

[0137] Optionally, in another embodiment of the present invention, one implementation of the initial synchronization point determination unit 802 includes:

[0138] The first sliding correlation unit is used to perform sliding correlation summation using the long training field of the traditional part of the currently received signal if the currently received signal is a traditional part signal and is a high signal-to-noise ratio signal, in order to obtain the first sliding correlation value.

[0139] The first initial synchronization point determination sub-unit is used to take the data point after the first sliding correlation value increment is less than the first threshold value twice consecutively as the initial synchronization point.

[0140] The specific working process of the units disclosed in the above embodiments of the present invention can be found in the corresponding method embodiments, and will not be repeated here.

[0141] Optionally, in another embodiment of the present invention, the secondary synchronization point determination unit 803 is further configured to set the secondary synchronization point as the initial synchronization point if the currently received signal is a long training field signal of a non-traditional part, and is a high signal-to-noise ratio signal or a beamforming transmission.

[0142] The specific working process of the units disclosed in the above embodiments of the present invention can be found in the corresponding method embodiments, and will not be repeated here.

[0143] Optionally, in another embodiment of the present invention, one implementation of the initial synchronization point determination unit 802 includes:

[0144] The second sliding correlation unit is used to perform sliding correlation summation using the long training field of the traditional part stored locally if the currently received signal is the traditional part signal and is not a high signal-to-noise ratio signal, in order to obtain the second sliding correlation value.

[0145] The second initial synchronization point determination sub-unit is used to take the correlation point where the second sliding correlation value, which is initially greater than the second threshold value, is located as the initial synchronization point.

[0146] The specific working process of the units disclosed in the above embodiments of the present invention can be found in the corresponding method embodiments, and will not be repeated here.

[0147] Optionally, in another embodiment of the present invention, one implementation of the secondary synchronization point determination unit 803 includes:

[0148] The third sliding correlation unit is used to perform sliding correlation summation on the long training field signal of the non-traditional part if the currently received signal is a long training field signal of the non-traditional part and is not a high signal-to-noise ratio signal and is transmitted without beamforming. This yields the third sliding correlation value.

[0149] The target correlation point determination unit is used to determine the correlation point where the third sliding correlation value, which is initially greater than the third threshold value, is located as the target correlation point.

[0150] The secondary synchronization point determination sub-unit is used to determine the relevant points corresponding to the time difference between the target relevant point and the target time interval as secondary synchronization points.

[0151] The target time interval is the time interval between the long training field of the traditional part and the long training field of the non-traditional part.

[0152] The specific working process of the units disclosed in the above embodiments of the present invention can be found in the corresponding method embodiments, and will not be repeated here.

[0153] Optionally, in another embodiment of the present invention, one implementation of the final synchronization point determination unit 804 includes:

[0154] The judgment unit is used to determine whether the difference between the secondary synchronization point and the initial synchronization point is greater than the threshold.

[0155] The final synchronization point determination subunit is used to adjust the target duration of the initial synchronization point to obtain the final synchronization point if the judgment unit determines that the difference between the secondary synchronization point and the initial synchronization point is greater than the threshold.

[0156] The target duration is determined based on the cyclic shift time of the long training field in the traditional part.

[0157] The final synchronization point determination sub-unit is also used to determine the final synchronization point if the judgment unit determines that the difference between the secondary synchronization point and the initial synchronization point is not greater than the threshold.

[0158] As can be seen from the above scheme, the present invention provides a synchronization device to counter multi-antenna CSD. The signal receiving unit 801 receives signals in real time. If the currently received signal is a traditional part signal and is not a high signal-to-noise ratio signal, the initial synchronization point determination unit 802 determines the initial synchronization point based on the long training field of the traditional part stored locally. If the currently received signal is a long training field signal of the non-traditional part and is not a high signal-to-noise ratio signal and is transmitted without beamforming, the secondary synchronization point determination unit 803 determines the secondary synchronization point based on the long training field of the non-traditional part stored locally. The final synchronization point determination unit 804 determines the final synchronization point based on the initial synchronization point and the secondary synchronization point. The final synchronization point helps the receiver reduce the CSD impact during the first path finding process when synchronizing with the received signal in a way that correlates with the locally stored signal when receiving a non-high signal-to-noise ratio signal, thereby helping the receiver obtain better synchronization and demodulation performance.

[0159] The functions described above in this document can be performed at least in part by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), and so on.

[0160] Another embodiment of the present invention provides an electronic device, such as... Figure 9 As shown, it includes:

[0161] One or more processors 901.

[0162] Storage device 902, on which one or more programs are stored.

[0163] When the one or more programs are executed by the one or more processors 901, the one or more processors 901 implement the synchronization method against multi-antenna CSD as described in the above embodiments.

[0164] Another embodiment of the present invention provides a storage medium on which a computer program is stored, wherein the computer program, when executed by a processor, implements the synchronization method against multi-antenna CSD as described in the above embodiments.

[0165] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0166] It should be noted that the computer-readable medium described above in this invention can be a computer-readable signal medium, a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this invention, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0167] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device.

[0168] Another embodiment of the present invention provides a computer program product, which, when executed, is used to perform the above-described synchronization method against multi-antenna CSD.

[0169] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from a storage device, or installed from a ROM. When the computer program is executed by a processing device, it performs the functions defined in the methods of the embodiments of the present invention.

[0170] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in this invention is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely exemplary forms for implementing the invention.

[0171] While several specific implementation details are included in the foregoing discussion, these should not be construed as limiting the scope of the invention. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0172] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with technical features of the present invention (but not limited to) that have similar functions.

Claims

1. A method of synchronizing against multi-antenna CSD, characterized by, The method comprises the following steps: receiving a signal in real time; if the current received signal is a legacy part signal and is not a high signal-to-noise ratio signal, determining an initial synchronization point according to a locally stored long training field of the legacy part; if the current received signal is a non-legacy part long training field signal and is not a high signal-to-noise ratio signal and is not a non-beamforming transmission, determining a secondary synchronization point according to a locally stored long training field of the non-legacy part; determining a final synchronization point according to the initial synchronization point and the secondary synchronization point.

2. The method of claim 1, wherein, The method further comprises the following steps: if the current received signal is a legacy part signal and is a high signal-to-noise ratio signal, determining an initial synchronization point according to a long training field of a legacy part of the current received signal; setting a secondary synchronization point as the initial synchronization point.

3. The method of claim 2, wherein, The step of determining the initial synchronization point according to the long training field of the legacy part of the current received signal if the current received signal is a legacy part signal and is a high signal-to-noise ratio signal comprises the following steps: if the current received signal is a legacy part signal and is a high signal-to-noise ratio signal, performing a sliding correlation sum on the long training field of the legacy part of the current received signal to obtain a first sliding correlation value; taking a data point, which is located after the first sliding correlation value and is less than a first threshold value for two consecutive times, as the initial synchronization point.

4. The method of claim 1, wherein, The method further comprises the following steps: if the current received signal is a non-legacy part long training field signal and is a high signal-to-noise ratio signal or is a beamforming transmission, setting a secondary synchronization point as the initial synchronization point.

5. The method of claim 1, wherein, The step of determining the initial synchronization point according to the long training field of the legacy part stored locally if the current received signal is a legacy part signal and is not a high signal-to-noise ratio signal comprises the following steps: if the current received signal is a legacy part signal and is not a high signal-to-noise ratio signal, performing a sliding correlation sum on the long training field of the legacy part stored locally to obtain a second sliding correlation value; taking a correlation point, in which the second sliding correlation value is greater than a second threshold value for the first time, as the initial synchronization point.

6. The method of claim 1, wherein, The step of determining the secondary synchronization point according to the long training field of the non-legacy part stored locally if the current received signal is a non-legacy part long training field signal and is not a high signal-to-noise ratio signal and is not a non-beamforming transmission comprises the following steps: if the current received signal is a non-legacy part long training field signal and is not a high signal-to-noise ratio signal and is not a non-beamforming transmission, performing a sliding correlation sum on the long training field of the non-legacy part stored locally to obtain a third sliding correlation value; taking a correlation point, in which the third sliding correlation value is greater than a third threshold value for the first time, as a target correlation point; taking a correlation point, which is located at a time interval corresponding to a difference between a time of the target correlation point and a target time interval, as the secondary synchronization point; wherein the target time interval is a time interval between the long training field of the legacy part and the long training field of the non-legacy part.

7. The method of claim 1, wherein, The step of determining the final synchronization point according to the initial synchronization point and the secondary synchronization point comprises the following steps: determining whether a difference between the secondary synchronization point and the initial synchronization point is greater than a threshold value; If it is judged that the difference between the second synchronization point and the initial synchronization point is greater than a threshold, the initial synchronization point is adjusted backward by a target time length to obtain a final synchronization point; wherein the target time length is determined according to a cyclic shift time amount of a long training field of a legacy part; If it is judged that the difference between the second synchronization point and the initial synchronization point is not greater than a threshold, the initial synchronization point is taken as the final synchronization point.

8. A synchronization apparatus against multi-antenna CSD, characterized by, The method comprises: a signal receiving unit, configured to receive a signal in real time; an initial synchronization point determining unit, configured to, if the currently received signal is a legacy part signal and is not a high signal-to-noise ratio signal, determine an initial synchronization point according to a locally stored long training field of a legacy part; a second synchronization point determining unit, configured to, if the currently received signal is a non-legacy part long training field signal and is not a high signal-to-noise ratio signal and is a non-beamforming transmission at the same time, determine a second synchronization point according to a locally stored non-legacy part long training field; a final synchronization point determining unit, configured to determine a final synchronization point according to the initial synchronization point and the second synchronization point.

9. An electronic device, comprising: The method comprises: one or more processors; a storage device having one or more programs stored thereon; when the one or more programs are executed by the one or more processors, the one or more processors implement the synchronization method against multi-antenna CSD as claimed in any one of claims 1 to 7.

10. A storage medium, characterized by a computer program is stored thereon, wherein the computer program is executed by a processor to implement the synchronization method against multi-antenna CSD as claimed in any one of claims 1 to 7.

Images