Dual-mode carrier communication system wireless signal synchronization method and device, and electronic equipment

Abstract

The application discloses a kind of dual-mode carrier communication system wireless signal synchronization method, device and electronic equipment, belong to power carrier communication technical field.The method includes: receiving wireless signal frame, and based on the sampling point position of wireless signal frame, extract the frame data matching with the predefined scrambling code sequence length, frame data is divided into multiple groups of data;According to scrambling code sequence, respectively each group of data is descrambled and is handled, obtains multiple groups of descrambled data;According to the preset autocorrelation times, multiple groups of descrambled data are autocorrelated and are calculated, obtain multiple autocorrelation results;Multiple autocorrelation results are superimposed to obtain superimposed result, and based on superimposed result determines the frame synchronization position of wireless signal frame.The application improves the synchronization effect of wireless signal, to realize high-quality wireless signal transmission.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of power carrier communication, and particularly relates to a wireless signal synchronization method and device for a dual-mode carrier communication system and electronic equipment. BACKGROUND

[0002] With the development of smart grid, Internet of Things and smart energy, power line carrier communication (PLC) technology has gradually become a commonly used data transmission method in low-voltage distribution networks and home internal networks. In order to simultaneously support high-speed data transmission and low-power communication, various high-performance dual-mode communication protocols have emerged, among which the High-speed Radio Frequency (HRF) protocol is a typical representative.

[0003] The HRF protocol supports high-speed and low-speed data transmission in different modes at the design stage, and can be applied to wireless signal transmission scenarios and power carrier communication environments. In such systems, the receiving end must complete high-precision frame synchronization under complex interference conditions in order to correctly extract subsequent data.

[0004] In related technologies, the wireless signal synchronization method based on the HRF protocol is usually based on the repetition structure of the short training field (STF) short symbol, and the frame synchronization is realized by performing delay autocorrelation calculation on adjacent short symbols and searching for a peak value on the autocorrelation curve. This method is simple to implement and has low computational complexity, and is therefore widely used.

[0005] However, in the power carrier communication environment, the above-mentioned method is significantly affected by noise interference, resulting in a sharp decline in synchronization performance, and even leading to synchronization failure. SUMMARY

[0006] The present application aims to at least solve one of the technical problems existing in the related art. To this end, the present application provides a wireless signal synchronization method and device for a dual-mode carrier communication system to improve the synchronization effect of wireless signals and realize high-quality wireless signal transmission.

[0007] In a first aspect, the present application provides a wireless signal synchronization method for a dual-mode carrier communication system, the method comprising:

[0008] receiving a wireless signal frame, and based on the sampling point position of the wireless signal frame, extracting frame data matching a predefined scrambling sequence length, the frame data being divided into multiple groups of data;

[0009] According to the scrambling sequence, each group of data is respectively descrambled to obtain multiple groups of descrambled data.

[0010] The self-correlation module is configured to perform self-correlation calculation on the multiple groups of descrambled data according to a preset self-correlation number, and obtain multiple self-correlation results.

[0011] The superposition module is configured to superimpose the multiple self-correlation results to obtain a superposition result, and determine a frame synchronization position of the wireless signal frame based on the superposition result.

[0012] In a second aspect, the present application provides a wireless signal synchronization device of a dual-mode carrier communication system, and the device comprises:

[0013] The extraction module is configured to receive a wireless signal frame, and extract frame data matching a predefined scrambling sequence length based on a sampling point position of the wireless signal frame, wherein the frame data is divided into multiple groups of data.

[0014] The descrambling module is configured to perform descrambling processing on each group of data according to the scrambling sequence, and obtain multiple groups of descrambled data.

[0015] The superposition module is configured to superimpose the multiple self-correlation results to obtain a superposition result, and determine a frame synchronization position of the wireless signal frame based on the superposition result.

[0016] In a third aspect, the present application provides an electronic device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the wireless signal synchronization method of the dual-mode carrier communication system according to the first aspect.

[0017] In a fourth aspect, the present application provides a non-transitory computer readable storage medium, which stores a computer program executable by a processor to implement the wireless signal synchronization method of the dual-mode carrier communication system according to the first aspect.

[0018] In a fifth aspect, the present application provides a chip, which comprises a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to run a computer program or instructions to implement the wireless signal synchronization method of the dual-mode carrier communication system according to the first aspect.

[0019] In a sixth aspect, the present application provides a computer program product, which comprises a computer program executable by a processor to implement the wireless signal synchronization method of the dual-mode carrier communication system according to the first aspect.

[0020] The wireless signal synchronization method of the dual-mode carrier communication system provided by the application, the device, the electronic equipment, the non-transitory computer readable storage medium, the chip and the computer program product, by the sampling point position based on the wireless signal, the frame data matched with the scrambling code sequence is extracted, irrelevant data is avoided to enter the calculation, the calculation redundancy is reduced, and the frame data is divided into multiple groups of data, which is convenient for cooperative verification by multiple groups of data, avoids errors of a single group of data, and affects subsequent calculation; by performing descrambling code processing on each group of data, the randomness of the scrambling code is removed, the structure of the data itself is restored, and subsequent autocorrelation calculation can capture the internal law of the frame, so that synchronization misjudgment is avoided; by presetting the autocorrelation times, the autocorrelation point number is adjusted, multiple autocorrelation calculations are performed on multiple groups of descrambling code data according to the autocorrelation times, which can provide guarantee for selection of subsequent autocorrelation peak values; at the same time, a reasonable delay range is covered, the autocorrelation peak value and noise energy are difficult to distinguish due to insufficient autocorrelation point number, so that the wireless signal can also ensure a high synchronization success rate when the signal-to-noise ratio is low; after that, the multiple autocorrelation results are superimposed, the signal-to-noise ratio of the synchronization point peak value of the wireless signal is enhanced, the influence of burst interference is further weakened, and the wireless signal synchronization under multiple signal-to-noise ratios is suitable for the application scene of weak wireless signal and strong interference, and a reliable reference for subsequent processing of the wireless signal is provided.

[0021] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and / or additional aspects and advantages of the application will become apparent and be readily understood by considering the following detailed description, from which the above-mentioned aspects and advantages of the application will become apparent and be readily understood, in conjunction with the accompanying drawings in which:

[0023] Figure 1 is a flowchart of a wireless signal synchronization method of a dual-mode carrier communication system provided by the application in some embodiments;

[0024] Figure 2 is a scrambling code sequence diagram provided by the application in some embodiments;

[0025] Figure 3 is a superimposition diagram of autocorrelation result amplitudes provided by the application in some embodiments;

[0026] Figure 4 is a superimposition process diagram of autocorrelation results in the wireless signal synchronization method of the dual-mode carrier communication system provided by the application in some embodiments;

[0027] Figure 5 is a descrambling code diagram provided by the application in some embodiments;

[0028] Figure 6 is a schematic diagram of the synchronization effect of a wireless signal of a dual-mode carrier communication system provided by the present application in some embodiments when the bandwidth is 40MHz;

[0029] Figure 7 is a schematic diagram of the synchronization effect of a wireless signal of a dual-mode carrier communication system provided by the present application in some embodiments when the bandwidth is 200Khz;

[0030] Figure 8 is a schematic diagram of the structure of a wireless signal synchronization device of a dual-mode carrier communication system provided by the present application in some embodiments;

[0031] Figure 9 is a schematic diagram of the structure of an electronic device provided by the present application in some embodiments. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0033] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, rather than to describe a particular order or primary and secondary relationships.

[0034] In the present application, "embodiments" means that the specific features, structures or characteristics described in conjunction with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0035] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "attachment" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B together, and the existence of B alone. In addition, the character " / " in the present application generally represents that the front and rear associated objects have an "or" relationship.

[0037] In the present application, "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0038] The HRF protocol has high requirements for the frame synchronization accuracy of wireless signals. When the signal-to-noise ratio in the application scenario is low, if the synchronization deviation is large, it is easy to cause the synchronization of the wireless signal to fail, and then cause the wireless signal to be unable to normally transmit data, trigger the communication system to be disconnected, and cause the communication data to be lost. The peak recognition accuracy of the traditional synchronization algorithm in a low signal-to-noise ratio environment is low, which easily leads to communication frame loss or synchronization failure, and seriously restricts the further improvement of the system performance.

[0039] The current mainstream synchronization method based on the HRF protocol mostly uses delay autocorrelation calculation based on STF. This method has poor robustness in a low signal-to-noise ratio environment, and the autocorrelation peak is easily affected by noise. Moreover, the design of a single delay interval cannot completely cover the delay of different channels when facing a large channel delay spread, and the autocorrelation peak is easily missed.

[0040] In addition, the above problems are particularly prominent in the power line carrier communication scenario. The power line communication chip is usually deployed in the power grid environment and is often affected by various interferences such as impulse noise, periodic noise, white noise, etc. Moreover, the communication channel characteristics are unstable, and the wireless signal is easily severely attenuated in transmission. These complex interference factors will cause the receiving link to have a burst of abnormalities or performance fluctuations, which seriously affects the accuracy of synchronization.

[0041] Therefore, there is an urgent need for a wireless signal synchronization mechanism that can maintain a high signal synchronization success rate in a low signal-to-noise ratio environment and can cover the delay characteristics of different channels.

[0042] Therefore, the application provides a wireless signal synchronization method of a dual-mode carrier communication system.

[0043] The wireless signal synchronization method of the dual-mode carrier communication system provided by the embodiments of the application will be described in detail below in combination with the drawings, specific embodiments and application scenarios.

[0044] The execution subject of the wireless signal synchronization method of the dual-mode carrier communication system can be an electronic device or a functional module or functional entity capable of implementing the wireless signal synchronization method of the dual-mode carrier communication system in the electronic device.

[0045] For example, the electronic device can be a terminal device such as a power line communication terminal, a concentrator device, a smart meter, a communication module embedded device or a communication test terminal. Alternatively, the electronic device can be a device with computing capability or a smart robot, which is used to perform signal receiving, processing and subsequent processing tasks.

[0046] The wireless signal synchronization method of the dual-mode carrier communication system provided by the embodiments of the application will be described below by taking the electronic device of the receiving end as an example.

[0047] Figure 1 is a flowchart of the wireless signal synchronization method of the dual-mode carrier communication system provided by some embodiments of the application. As shown in Figure 1 The wireless signal synchronization method of the dual-mode carrier communication system includes steps 110-150.

[0048] In step 110, a wireless signal frame is received, and frame data matching a predefined scrambling code sequence length is extracted based on the sampling point position of the wireless signal frame. The frame data is divided into multiple groups of data.

[0049] The wireless signal frame is a basic unit of data transmission in wireless communication. The transmitting end of the wireless signal encapsulates original data into a structure containing one or more of synchronization information, valid data and check information according to a specific protocol format, so as to facilitate the identification and analysis of the receiving end of the wireless signal.

[0050] The arrival sampling point position of a wireless signal frame refers to the preliminary judgment made by the receiver, based on specific detection conditions or a preset reference point, of the possible sampling point position of the wireless signal frame when receiving the wireless signal. This position is the starting reference point used by the receiver to intercept a segment of candidate frame data, but it does not represent the true starting position of the wireless signal frame. The true starting position needs to be determined by comprehensive calculations combining descrambling, multi-interval delay autocorrelation, phase difference compensation, and superposition decision.

[0051] A scrambling sequence is a pseudo-random sequence set in a wireless communication system. The signal transmitter uses it to scramble frame data, that is, to disrupt the data pattern and avoid interference caused by long strings of signals. The length of the scrambling sequence is predetermined by the communication protocol.

[0052] Figure 2 This is a schematic diagram of the scrambling sequence provided in some embodiments of the present invention, such as... Figure 2 As shown, the sequence consists of 10 data units of the digits -1 or 1. Using such a sequence, the original data can be scrambled to change its characteristics and avoid long, identical data sequences or overly strong regularities in the original data.

[0053] Specifically, the receiving end first receives the wireless signal frame and determines the sampling point position of the wireless signal. After that, the receiving end extracts frame data with a length matching the scrambling sequence length based on the sampling point position of the wireless signal, according to the scrambling sequence length specified in the communication protocol. The frame data is then divided into multiple data groups according to the grouping rules, and the obtained multiple data groups are used for subsequent descrambling processing.

[0054] For example, if the predefined scrambling sequence length is S sampling points, the receiver traces back along the previous direction of the received data near the sampling points of the frame to extract frame data of length 10×S, ensuring that the extracted data covers the short training field (STF) of the start region of the radio signal frame. The extracted frame data contains multiple repeating short symbols, each with a length equal to the scrambling sequence length.

[0055] The receiver divides the frame data into multiple groups of short symbol data according to the scrambling sequence length, providing a data basis for subsequent descrambling processing, sliding window multi-interval delay autocorrelation calculation, and frame synchronization decision.

[0056] By extracting frame data that matches an integer multiple of the scrambling sequence length, the integrity of the short training field is ensured, thereby obtaining a clear synchronization peak in the subsequent multi-interval delay autocorrelation calculation and frequency offset compensation superposition process, thus enabling precise determination of the starting position of the wireless signal frame.

[0057] Step 120: According to the scrambling sequence, descramble each group of data to obtain multiple groups of descrambled data.

[0058] The wireless communication system cannot directly use the data groups processed by the scrambling sequence at this time. The reason is that the data format after scrambling does not match the subsequent processing requirements. In order to perform subsequent autocorrelation calculation and other operations on the data, the multiple groups of data obtained need to be descrambled.

[0059] For the multiple data groups obtained by division, the receiving end uses the same scrambling sequence as the sending end to perform reverse operation on each data group in the multiple data groups respectively, so as to restore the original data. The process of using the scrambling sequence to restore the original data of the data group is called descrambling. The descrambled data obtained after each data group is descrambled is integrated to obtain multiple groups of descrambled data.

[0060] It should be noted that for multiple data groups that need to be descrambled, the receiving end can simultaneously descramble through a multi-core baseband chip to improve the processing efficiency of the data groups and improve the real-time performance of the wireless communication system. In addition, when a data group in the multiple groups of data fails to be descrambled due to interference, the result of the descrambling failure only affects the current data group, and the descrambling result of the other groups is still effective and can be used for subsequent calculation, thereby improving the robustness of the overall processing.

[0061] Step 130, performing autocorrelation calculation on the multiple groups of descrambled data according to a preset autocorrelation number to obtain multiple autocorrelation results.

[0062] The autocorrelation calculation is a mathematical operation for measuring the correlation between each group of descrambled data and the descrambled data at different positions.

[0063] In this embodiment, after the receiving end completes the descrambling processing of the multiple groups of frame data, the receiving end performs multiple delay autocorrelation calculations based on the multiple groups of descrambled data according to a preset autocorrelation number, to obtain multiple autocorrelation results corresponding to multiple different group intervals.

[0064] When performing autocorrelation calculation, one group of descrambled data is autocorrelated with another group of descrambled data to measure the similarity characteristics of the two groups of data. Through the above method, autocorrelation calculation is performed according to a preset autocorrelation number, and finally multiple autocorrelation results are obtained.

[0065] The autocorrelation number is determined according to the number of short symbol repetitions of the short training field in the wireless signal frame. For example, when the short training field is composed of multiple identical short symbols, the receiving end can select multiple different group intervals (for example, one short symbol length, two short symbol lengths, or three short symbol lengths) to perform delay autocorrelation calculation, so the autocorrelation number is equal to the number of selected group intervals.

[0066] In some embodiments, the number of autocorrelations can also be determined according to the system synchronization performance requirements and the repetition characteristics of the short training field. In an environment with a high signal-to-noise ratio, the number of autocorrelations can be reduced to reduce computational complexity; in an environment with a large amount of noise interference, the number of autocorrelations can be increased to superimpose the correlation results of multiple inter-group intervals to improve synchronization robustness.

[0067] For different wireless signal synchronization scenarios, the more the number of autocorrelations, the more the number of signal feature sampling and matching, which can more fully accumulate effective signal energy and suppress noise interference, thereby reducing the synchronization error rate caused by poor signal quality. However, the number of autocorrelations is not the more the better, in some application scenarios, too much calculation will occupy the processor, memory and other resources of the device, which may cause synchronization delay to increase and affect the real-time performance of communication. Therefore, the number of autocorrelations needs to be dynamically adjusted according to the signal-to-noise ratio of the wireless signal and the number of points in the current frequency band.

[0068] In addition, in the HRF protocol, the number of sampling points of the synchronization symbol under different frequency band configurations is significantly different, for example, in the three frequency band configurations of option1, option2 and option3, the number of sampling points of the synchronization symbol is 64 sampling points, 32 sampling points and 16 sampling points, respectively. Due to the small number of sampling points of the synchronization symbol in some frequency band configurations (such as option2 and option3), in a low signal-to-noise ratio environment, the autocorrelation peak obtained by the delay autocorrelation operation based on the synchronization symbol is not obvious enough, which leads to a significant decrease in frame synchronization performance, and even synchronization failure.

[0069] Based on this, in some embodiments, the determination of the number of autocorrelations includes: selecting a target number of autocorrelations from a plurality of protocol-predefined numbers of autocorrelations according to the frequency band configuration adopted in the current communication, and the frequency band configuration is any one of the three frequency bands specified in the HRF protocol.

[0070] Among them, when the first frequency band (opt1) is selected, the number of autocorrelations is determined as a first preset number of autocorrelations; when the second frequency band (opt2) is selected, the number of autocorrelations is determined as a second preset number of autocorrelations; and when the third frequency band (opt3) is selected, the number of autocorrelations is determined as a third preset number of autocorrelations. The first preset number of autocorrelations is suitable for a frequency band with a synchronization symbol sampling point number of sixteen, the second preset number of autocorrelations is suitable for a frequency band with a synchronization symbol sampling point number of thirty-two, and the third preset number of autocorrelations is suitable for a frequency band with a synchronization symbol sampling point number of sixty-four.

[0071] According to the frequency band configuration predefined by the HRF protocol, the number of preset autocorrelations is dynamically selected in combination with the number of synchronization symbol sampling points and the signal-to-noise ratio level of the communication environment, so that in the case of fewer sampling points or lower signal-to-noise ratio, the repeated short symbol information can be fully utilized to enhance the synchronization characteristics; in the case of more sampling points, the number of autocorrelations is automatically reduced to reduce the computational complexity, and the balance between synchronization performance and computational complexity is achieved.

[0072] In some other embodiments, the determination of the number of autocorrelations further includes: obtaining the signal-to-noise ratio of the current wireless signal frame, and selecting a target number of autocorrelations from a plurality of preset numbers of autocorrelations according to the signal-to-noise ratio, wherein the plurality of preset numbers of autocorrelations correspond to different signal-to-noise ratio intervals respectively; wherein the lower the signal-to-noise ratio, the higher the preset number of autocorrelations corresponding thereto, and the higher the signal-to-noise ratio, the lower the preset number of autocorrelations corresponding thereto.

[0073] The signal-to-noise ratio refers to the ratio of the energy of the signal to the energy of the noise, and is used to measure the signal quality. When the signal-to-noise ratio of the signal is low, it reflects that the quality of the wireless signal at this time is poor, and synchronization is more difficult, and the number of autocorrelations needs to be increased to improve the synchronization success rate of the wireless signal.

[0074] By dynamically determining the number of autocorrelations according to the signal-to-noise ratio of the current communication environment, when the signal-to-noise ratio is low, more autocorrelations are selected to enhance the amplitude of the autocorrelation peak, thereby improving the frame synchronization performance in the low signal-to-noise ratio environment; when the signal-to-noise ratio is high, fewer autocorrelations are selected to reduce the computational complexity and improve the processing efficiency.

[0075] In some other embodiments, the preset numbers of autocorrelations can also correspond to different frequency band configurations and different signal-to-noise ratio intervals, so that in the case of fewer synchronization symbol sampling points or lower signal-to-noise ratio, the corresponding preset number of autocorrelations is selected to enhance the autocorrelation peak, and in the case of more synchronization symbol sampling points and higher signal-to-noise ratio, the corresponding preset number of autocorrelations is selected to reduce the computational complexity.

[0076] Of course, the determination of the number of autocorrelations in the embodiments of the present application is not limited to the above-mentioned method based on the protocol frequency band configuration and the signal-to-noise ratio. In other embodiments, the number of autocorrelations can also be determined according to the interference level in the current communication frequency band, the historical frame synchronization performance statistical results, the hardware processing capability of the receiving end, the target synchronization accuracy requirement, etc. to adapt to the synchronization performance requirements and computational resource constraints in different application scenarios.

[0077] Step 140, superimpose a plurality of autocorrelation results to obtain a superimposed result, and determine the frame synchronization position of the wireless signal frame based on the superimposed result.

[0078] The receiving end first acquires a plurality of autocorrelation results; then merges the autocorrelation results into one superposition result through superposition operation; and finally analyzes the superposition result to locate the frame synchronization position of the wireless signal frame through a wireless signal synchronization determination condition.

[0079] For example, the superposition operation may be one or more of summation, weighted summation, etc.; and the synchronization determination condition may be one or more of peak threshold determination, peak uniqueness verification, etc.

[0080] The wireless signal synchronization method of the dual-mode carrier communication system provided by the embodiment of the application extracts frame data matched with the scrambling code sequence based on the sampling point position of the wireless signal, avoids irrelevant data from entering the calculation, reduces the calculation redundancy, divides the frame data into multiple groups of data, facilitates the cooperative verification through the multiple groups of data, avoids the error of a single group of data, and influences the subsequent calculation; the scrambling code processing is performed on each group of data to remove the randomness of the scrambling code and restore the structure of the data itself, facilitating the subsequent autocorrelation calculation to capture the internal law of the frame and avoiding the synchronization misjudgment; the autocorrelation number is adjusted through the preset autocorrelation number, the multiple groups of descrambled data are subjected to multiple autocorrelation calculations according to the autocorrelation number, which can provide guarantee for the selection of the autocorrelation peak value; meanwhile, a reasonable delay range is covered to avoid the difficulty in distinguishing the autocorrelation peak value from the noise energy due to the insufficient autocorrelation number, so that the wireless signal can also ensure a high synchronization success rate when the signal-to-noise ratio is low; after that, the multiple autocorrelation results are superimposed to enhance the signal-to-noise ratio of the synchronization point peak value of the wireless signal, further weaken the influence of the burst interference, and be suitable for the wireless signal synchronization under multiple signal-to-noise ratios, and still ensure a high synchronization success rate in the application scene of weak wireless signal and strong interference, thereby providing a reliable reference for the subsequent processing of the wireless signal.

[0081] When the HRF protocol is applied to a narrow bandwidth scene, the number of autocorrelation points is insufficient, and the signal peak value is easily difficult to distinguish from the noise, so for the autocorrelation calculation of the descrambled data, the autocorrelation number suitable for the current application scene needs to be set. If the autocorrelation number is randomly selected, the effective information is easily missed.

[0082] Based on this, in some embodiments, the multiple groups of descrambled data are subjected to autocorrelation calculation according to the preset autocorrelation number, and multiple autocorrelation results are obtained, specifically including: selecting multiple group intervals based on the total number of the multiple groups of descrambled data; wherein the number of group intervals is the same as the preset autocorrelation number, and the group interval is an integer multiple of the length of the scrambling code sequence; and the multiple groups of descrambled data are subjected to multiple autocorrelation calculations according to each group interval to obtain multiple autocorrelation results corresponding to the autocorrelation number.

[0083] Specifically, the receiving end first determines a plurality of inter-group intervals, which are integer multiples of the length of the scrambling sequence. For example, when the length of the scrambling sequence is S, the inter-group intervals include, but are not limited to, S, 2S, 3S, etc. After that, for each inter-group interval, the receiving end performs autocorrelation calculation on a plurality of groups of descrambled data. In the autocorrelation calculation, one group of descrambled data is autocorrelated with another group of descrambled data, and the interval between the two groups of data is the currently adopted inter-group interval. In this way, the similarity characteristics of the two groups of data are measured. Through such autocorrelation calculation multiple times according to different inter-group intervals, the autocorrelation results corresponding to each inter-group interval are finally obtained. After performing autocorrelation calculation on a plurality of groups of descrambled data according to the same inter-group interval, the average or combined value of the results of the groups, etc. can be taken as the final autocorrelation result of the inter-group interval.

[0084] It should be noted that the number of inter-group intervals is the same as the number of autocorrelation times, because if the number of autocorrelation times is less than the number of inter-group intervals, the autocorrelation results of some intervals will be missing, and if the number of autocorrelation times is more than the number of inter-group intervals, redundant operations of calculating the same interval will occur, wasting computing resources. As for selecting the inter-group interval as an integer multiple of the length of the scrambling sequence, the reason is that in a wireless communication system, the scrambling sequences of the receiving end and the transmitting end must be strictly synchronized, and the scrambling sequence has a fixed period, and the period length is the length of the scrambling sequence. For the correlation regularity of data groups, when the interval of two groups of scrambling sequences is an integer multiple of the period, the autocorrelation value of the two groups will reach the maximum value, i.e., the similarity is the highest, and if the interval is not an integer multiple, the autocorrelation value will decrease rapidly, which is not conducive to the calculation of autocorrelation results and the synchronization of wireless signals.

[0085] In the above embodiment, a plurality of inter-group intervals that are integer multiples of the length of the scrambling sequence are selected, and the number of inter-group intervals is the same as the number of autocorrelation times, which can match the periodicity of the synchronization sequence, avoid missing effective information with a single interval, and through multiple autocorrelation calculations, linear accumulation of signal energy and random cancellation of noise can be realized, which significantly improves the peak signal-to-noise ratio and solves the problem of low peak-to-noise discrimination caused by insufficient effective points in a narrow bandwidth scenario.

[0086] In wireless communication, signal transmission will produce phase rotation due to frequency deviation, and the amount of phase rotation is related to the time interval. If the autocorrelation results are directly superimposed, the superposition of autocorrelation results of different intervals will cause phase confusion, affecting the superposition result.

[0087] Based on this, in some embodiments, the superposition result is obtained by superimposing the plurality of autocorrelation results, including: determining a reference autocorrelation result in the plurality of autocorrelation results; compensating the remaining autocorrelation results in the plurality of autocorrelation results based on the reference autocorrelation result, and superimposing the compensated autocorrelation results and the reference autocorrelation result to obtain the superposition result.

[0088] To increase the number of autocorrelation results, the most direct method is to increase the number of autocorrelation involved in superposition, that is, to use autocorrelation results corresponding to multiple inter-group intervals, but autocorrelation data of different inter-group intervals are affected by frequency offset, and their phase rotation factors are different. If superimposed directly, the phases of signal components may cancel each other out, resulting in deterioration of correlation calculation. Therefore, it is necessary to compensate the autocorrelation results for frequency offset to maximize the optimization effect of autocorrelation results on wireless signal synchronization.

[0089] Specifically, the receiving end selects any autocorrelation result corresponding to an interval as a reference autocorrelation result from the autocorrelation results corresponding to multiple inter-group intervals respectively, calculates the phase difference between the autocorrelation results corresponding to other inter-group intervals and the reference autocorrelation result, and then compensates the autocorrelation results corresponding to other inter-group intervals according to the obtained phase difference, so that the phases of these autocorrelation results and the reference autocorrelation result are consistent.

[0090] It should be noted that when selecting the reference autocorrelation result, the smaller the inter-group interval, the better the effect of frequency offset compensation, because the frequency deviation in wireless signal transmission will cause the signal phase to accumulate linearly over time, and the phase deviation is proportional to the time interval. The smaller the inter-group interval, the closer the time sequence distance of the two groups of data, and the higher the similarity of the signal characteristics. For example, among the inter-group intervals of S, 2S, 3S, etc., the autocorrelation result corresponding to S is selected as the reference autocorrelation result, and the frequency offset compensation effect obtained is the best.

[0091] In addition, in different application scenarios, the autocorrelation result or the cross-correlation result can be a real number or a complex number. Specifically, if the original signal is a real signal, such as an audio signal, a single analog voltage signal, etc., the result is a real number; if the transmitted signal is a complex signal, such as a quadrature frequency division multiplexing signal, a modulated signal, etc. Signals containing in-phase components and quadrature components, etc. The result is a complex number. For a wireless communication system using HRF communication protocol, the wireless signal is a complex signal, and the autocorrelation result and the cross-correlation result are also complex numbers.

[0092] In the above embodiments, by selecting a reference autocorrelation result, the autocorrelation results of multiple intervals are compensated for frequency offset, the calculation amount is controllable, the frequency offset compensation can be realized without traversing all cross-compensation, and the reference autocorrelation result is fixed, avoiding errors caused by inconsistent reference to a certain extent, and ensuring that subsequent superposition can effectively improve the synchronization performance.

[0093] For the calculation between the reference autocorrelation result and the autocorrelation results of multiple groups of intervals, if the phase difference is directly calculated by subtracting the two autocorrelation results, the autocorrelation results contain noise, which will cause the phase jitter to be severe, the phase difference error to be extremely large, and the subsequent frequency offset compensation to be completely invalid, and even a new phase deviation is introduced.

[0094] Based on this, in some embodiments, based on the reference autocorrelation result, the other autocorrelation results in the plurality of autocorrelation results are compensated, specifically including: for any autocorrelation result in the remaining autocorrelation results, the reference autocorrelation result and the autocorrelation result are cross-correlated to obtain a cross-correlation result; wherein the cross-correlation result is a complex number; the cross-correlation result is energy-normalized to obtain a normalized cross-correlation result, and the phase value in the normalized cross-correlation result in the complex number form is extracted to obtain the phase difference between the two; and the autocorrelation result is phase-compensated according to the phase difference to obtain a compensated autocorrelation result.

[0095] The cross-correlation calculation is a mathematical operation for measuring the correlation between the autocorrelation results of different groups of intervals, which obtains a result reflecting the similarity between the two by calculating the product integral or sum of one autocorrelation result and another autocorrelation result.

[0096] The energy normalization processing is a standardization operation on the cross-correlation result, which can be achieved by dividing the cross-correlation result by its modulus, i.e. the amplitude of the complex number, for example. The purpose is to eliminate the interference of amplitude difference and only keep the key feature information such as phase.

[0097] Specifically, the receiving end selects any two autocorrelation results of different groups of intervals, performs cross-correlation operation on the two, obtains a cross-correlation result in the form of a complex number, performs energy normalization operation on the cross-correlation result in the form of a complex number, obtains a normalized cross-correlation result, and extracts the phase value from the normalized cross-correlation result. The phase value is the phase difference between the two autocorrelation results of different groups of intervals. Using the extracted phase difference, the receiving end performs phase rotation processing on one of the two autocorrelation results, so that the phase of the autocorrelation result is consistent with the phase of the other autocorrelation result, thereby completing the frequency offset compensation.

[0098] Phase rotation is a process of adjusting the phase of a signal through complex number operation, which can make the phases of two signals consistent, thereby offsetting the phase deviation caused by frequency offset, achieving frequency offset compensation, offsetting the signal phase distortion caused by the mismatch of the frequencies of the oscillators of the sending end and the receiving end, and ensuring the accuracy of signal transmission and processing. The phase rotation may be, for example, multiplication by a complex exponential function with a specific phase.

[0099] The following provides a detailed explanation of the cross-correlation calculation, energy normalization, and frequency offset compensation processes between the autocorrelation results in the embodiments of the present invention.

[0100] For lengths of all Two complex signals (i.e., the autocorrelation result) and The cross-correlation function is as follows:

[0101] (1)

[0102] in, It is a delay parameter, representing the signal. Relative to signal The time offset, Indicates the sampling point index of the signal. Represents complex signals In the The conjugate complex number of the values ​​at each sampling point.

[0103] Simplify and take This is a direct dot product, applicable to short-time stationary signals, yielding the following formula:

[0104] (2)

[0105] in, It is a complex number, and its phase is... Compared to The phase difference. To eliminate the influence of signal amplitude, the cross-correlation results are normalized using the following formula:

[0106] (3)

[0107] (4)

[0108] (5)

[0109] It is the normalized cross-correlation result, with a magnitude range of [0,1], and its phase... It is still a phase difference; For signal Total energy, For signal Total energy, , For signal and The modulus.

[0110] Let the normalized phase difference By using the following formula Perform phase rotation:

[0111] (6)

[0112] is a complex number, is a complex number after phase compensation, is a complex number at the first sampling point, and n is a complex number after phase compensation. is a complex number after phase compensation, ignores the time-varying phase difference caused by residual noise and frequency offset.

[0113] For phase compensation of a time-domain complex signal, the following process can be understood:

[0114] The polar coordinate form of a complex number is described as:

[0115] (7)

[0116] wherein, is an amplitude, is a phase, and phase compensation is equivalent to counterclockwise rotation of the phase of by :

[0117] (8)

[0118] In the above embodiment, by performing energy normalization processing on the cross-correlation result, the interference of signal amplitude difference on phase extraction can be well eliminated, the accuracy of the phase value is ensured, the calculation is simple, frequency offset estimation is not required, the real phase difference can be accurately obtained and phase alignment can be realized in the presence of noise interference and frequency offset, effective signal enhancement and noise suppression after superposition are ensured, phase difference calculation distortion and compensation failure are avoided, and the wireless signal frame synchronization success rate is improved in a low signal-to-noise ratio or large frequency offset scenario.

[0119] For the autocorrelation result after frequency offset compensation, the autocorrelation result is a complex number at this time, and the information of the wireless signal is carried in the real part and the imaginary part of the complex number, and the amplitude and phase characteristics of the signal are reflected by the two parts. In the common correlation technology, only the amplitudes are superimposed, and the phases are not superimposed. Figure 3 is a schematic diagram of amplitude superposition of the autocorrelation result provided in some embodiments of the present application, as shown in Figure 3 In the upper branch, the left input data data0'~data8' are multiplied point by point with another group of data conj(data1')~conj(data9'), represented by the symbol , conj represents the conjugate operation of a complex number, and sum represents the summation operation of the results of point-by-point multiplication.Figure 3 In the sum of the upper branch and the lower branch, the results of the point-by-point multiplication are summed, and the results after the sum operation are calculated in the next step. abs / pow represents the amplitude (absolute value abs) or power (square pow) calculation of the sum of the upper branch and the lower branch. It is easy to understand that the left input data data0'~data7' of the lower branch is multiplied point by point with another group of data conj(data2')~conj(data9'), and the same point-by-point multiplication and sum operation is performed. The results of the upper branch and the lower branch are finally summed, and the results of the two branches are added to obtain the correlation value corr.

[0120] In the process of wireless signal synchronization, the receiving signal end continuously receives signals from the sending end based on time. Therefore, for the synchronization process of wireless signals, if a single fixed point is operated, not only will the processing device be burdened by the continuous accumulation of signals, but also it will be difficult to achieve synchronization due to the limited range of processed data.

[0121] Therefore, in some embodiments, the autocorrelation calculation is performed on multiple groups of descrambled data according to the autocorrelation times, and autocorrelation results corresponding to multiple group interval are obtained. Specifically, for any group interval, a sliding window with a length equal to the length of the scrambling code sequence is set on the multiple groups of descrambled data. For the current window, another window located at the starting position of the current window by the group interval is selected, and the corresponding sampling points in the two windows are conjugate multiplied in the complex domain to obtain a multiplication result. The multiplication result is accumulated in the current window to obtain a single autocorrelation value corresponding to the starting position of the current window. With the sliding of the window starting position, the calculation is repeated, and all single autocorrelation values in the current window are arranged in order of the window starting position to form an autocorrelation result corresponding to the group interval. The above calculation is repeated for different group intervals to obtain autocorrelation results corresponding to multiple group intervals.

[0122] The sliding window is a time range for statistical correlation in the signal, and is a data analysis window with a fixed length of the scrambling code sequence length, which can slide along the data sequence to intercept signal segments at different positions for calculation.

[0123] Specifically, the receiving end selects any one of the preset multiple group interval as the interval reference for current calculation, creates a fixed-length sliding window on the sequence of the multiple groups of descrambled data, positions the starting position of the sliding window at the starting end of the sequence of the descrambled data, and positions another window with the same length as the current window as a comparison window by moving the starting position of the current window according to the selected group interval. The sampling points in the current window and the comparison window that correspond to each other are paired, and a conjugate multiplication operation is performed on each pair of matched sampling points, that is, the sampling points in the comparison window are conjugated, and then multiplied by the corresponding sampling points in the current window to obtain a set of multiplication results in complex form.

[0124] It should be noted that in the conjugate multiplication operation, the sampling points in the current window can also be conjugated, and then multiplied by the sampling points in the comparison window.

[0125] The multiplication results of all paired sampling points in the current window are accumulated, and the real parts are added together and the imaginary parts are added together, to obtain a comprehensive complex value, which is the single autocorrelation value corresponding to the starting position of the current window. The starting position of the current window is moved by 1 sampling point, and a new comparison window is positioned according to the same group interval. The conjugate multiplication and accumulation process is repeated for the new current window and the comparison window to generate a new single autocorrelation value. The window is continuously slid until the starting position of the window traverses the entire sequence of descrambled data. All generated single autocorrelation values are arranged in the order of the starting positions of the windows to obtain the autocorrelation result corresponding to the current group interval.

[0126] After that, the receiving end traverses the multiple group intervals, and repeats the above process for each of the other preset group intervals until all autocorrelation results are generated, and multiple autocorrelation results corresponding to the multiple group intervals are obtained.

[0127] The theoretical process of autocorrelation calculation will be described in detail below in conjunction with the formula.

[0128] Let be the signal received by the receiving end, be the original signal sent by the transmitting end, which is a known useful signal. Let be the channel coefficient, representing the attenuation, i.e., the phase change, of the signal affected by the channel during transmission, which can also be understood as the change rate of the signal after passing through the channel. Then there is the following relationship:

[0129] (9)

[0130] wherein is noise, and there is the following relationship:

[0131] (10)

[0132] (11)

[0133] Assume that the calculation is made under the condition that the energy of the original signal is fixed and the average energy of the channel is fixed, where, is the conjugate transpose, represents the calculation of the signal energy, and the result is equal to S, S being the length of the scrambling sequence, and represents the energy fixation of the original signal. Equation (11) refers to the overall attenuation / gain of the channel to the signal being 1, and the average energy being fixed.

[0134] The autocorrelation result of the previous data group and the next data group is calculated:

[0135] (12)

[0136] (13)

[0137] where the cross-correlation result of the previous data group and the next data group is calculated, equation (12) is the previous group of data, and equation (13) is the next group of data. is the channel coefficient of the previous group of data, is the noise of the previous group of data. It is easy to understand that, is the channel coefficient of the next group of data, is the noise of the previous group of data. For the first group of data, .

[0138] The channel coefficient is calculated based on the following equation:

[0139] (14)

[0140] where, is the imaginary unit, is the frequency offset, i.e., the deviation between the frequency of the received signal and the original frequency of the transmitting end; is the time difference, i.e., the time interval between the two signals of and .

[0141] Thus, the autocorrelation value is:

[0142] (15)

[0143] Define a new noise , Therefore, the autocorrelation sum of a single S length is:

[0144] (16)

[0145] Taking the autocorrelation of the data with the scrambling sequence length of 10S as an example, the calculation is as follows:

[0146] (17)

[0147] At this time, the signal-to-noise ratio of the signal is:

[0148] (18)

[0149] As the length of S increases, the signal-to-noise ratio of the autocorrelation peak improves, so in the HRF, the performance of the large bandwidth scenario will be significantly better than that of the narrow bandwidth scenario, and it can be seen that the noise energy of the autocorrelation is the square of the original noise energy, so when the original data signal-to-noise ratio is lower than 0dB, the autocorrelation performance will deteriorate rapidly.

[0150] Especially for the mode with a working bandwidth of 200Khz in the HRF protocol, i.e., the opt3 mode, the number of points of the fast Fourier transform is set to 32. This setting directly leads to insufficient effective data points available for autocorrelation calculation, making it difficult for the synchronization peak value obtained through autocorrelation operation to form a significant amplitude difference with the noise energy. In this case, when the signal-to-noise ratio in the communication environment is low, the noise interference will further blur the peak value characteristics, making it difficult for the receiving end to accurately distinguish between the true synchronization peak value and the noise pseudo-peak value, ultimately leading to a significant decrease in the success rate of wireless signal synchronization.

[0151] In the above embodiments, by performing multiple autocorrelation calculations on multiple groups of descrambled data with multiple group interval spacings, signals of different time spans can be covered, the number of autocorrelation calculations is increased, even if the periodic characteristics of the synchronization identifier are blurred due to channel interference, the relevant peak values can still be obtained through calculation with multiple interval spacings, avoiding the loss of synchronization information due to a single interval error, and through the fusion of the results of multiple interval spacings, the peak value characteristics of the effective signal can be further amplified, ultimately improving the accuracy of the judgment of the frame synchronization position of the wireless signal, improving the applicability of the synchronization algorithm under various channel conditions, and improving the synchronization success of the wireless signal.

[0152] After the superposition result is calculated, the synchronization position of the wireless signal frame is determined according to the superposition result. The synchronization position of the wireless signal frame needs to be selected according to the characteristic that the amplitude of the superposition result is positively correlated with the signal correlation, otherwise the non-key point position with a smaller amplitude in the superposition result may be incorrectly determined as the frame synchronization position, leading to synchronization failure.

[0153] Based on this, in some embodiments, the frame synchronization position of the wireless signal frame is determined based on the superposition result, specifically including: searching for a peak point with the largest amplitude based on the superposition result; in the case that the peak point satisfies the autocorrelation threshold condition, determining the frame synchronization position of the wireless signal based on the time position corresponding to the peak point.

[0154] The acquired superposition result further processed from the autocorrelation result is essentially the enhancement of the signal autocorrelation characteristics and the suppression of the noise. In this process, the autocorrelation peak at the synchronization sequence is amplified. Due to the strong correlation of the synchronization sequence, the autocorrelation result itself has a higher amplitude. After the superposition processing, the energy of the autocorrelation component corresponding to the synchronization sequence is accumulated, and the amplitude is further increased to form the maximum peak point in the superposition result. The noise and the non-synchronization component are suppressed. The autocorrelation result amplitude of the non-synchronization part in the wireless signal frame is low, and the noise has randomness. After superposition, they will cancel each other out and will not form a significant peak.

[0155] Therefore, the peak point in the superposition result is essentially the result of the synchronization sequence after the autocorrelation result superposition processing. The corresponding position is the frame synchronization position.

[0156] The receiving end first arranges all the autocorrelation superposition results after the frequency offset compensation according to their corresponding sampling time sequence. Based on this sorting result, the receiving end constructs an autocorrelation time spectrum. The autocorrelation time spectrum is a two-dimensional data spectrum with the time axis as the horizontal axis and the autocorrelation amplitude as the vertical axis. On the autocorrelation time spectrum, the receiving end searches for the peak point with the maximum amplitude. Since the starting position of the wireless signal frame will form a significant energy peak in the autocorrelation calculation due to the periodic characteristics of the signal structure, the position corresponding to this peak point is the frame synchronization position of the wireless signal frame.

[0157] In the above embodiment, by selecting the peak point with the maximum amplitude, the synchronization feature with the strongest signal correlation and the most concentrated energy is selected. This synchronization feature can more accurately reflect the true position of the synchronization sequence, avoid synchronization failure due to the limitations of a single superposition result, and has simple and intuitive calculation logic. The receiving end can quickly locate the peak without complex feature extraction or multi-dimensional matching, reducing the hardware implementation difficulty and software operation amount.

[0158] In some embodiments, the process of superimposing multiple autocorrelation results can also be to calculate the phase difference between the autocorrelation results of any two different group intervals, and to compensate the frequency offset of one of them using the phase difference. The autocorrelation results after frequency offset compensation are superimposed with the other one to obtain the superposition result. Specifically, the receiving end selects any two autocorrelation results with different intervals from the autocorrelation results corresponding to multiple group intervals that have been obtained, calculates the phase difference between the two autocorrelation results, and compensates the frequency offset of one of the autocorrelation results according to the calculated phase difference to adjust its phase and offset the influence of the frequency offset. After that, the autocorrelation result after frequency offset compensation is superimposed with the other autocorrelation result that has not been compensated, and the result of the superposition operation is taken as the superposition result.

[0159] For example, preset group interval is S, 2S and 3S. The receiving end respectively performs autocorrelation calculation according to the group interval S, 2S and 3S, and obtains autocorrelation A1, A2 and A3 corresponding to the group interval S, 2S and 3S respectively. The receiving end calculates the phase difference σ1 of the autocorrelation result A1 of the group interval S and the autocorrelation result A2 of the group interval 2S, performs frequency offset compensation on one of the autocorrelation results, for example, A1 based on the phase difference σ1, obtains the frequency offset compensated A1', and then superimposes the frequency offset compensated A1' and the corresponding other autocorrelation result A2 to obtain the superimposition result SUM1. Similarly, the receiving end calculates the phase difference σ2 of the autocorrelation result A2 of the group interval 2S and the autocorrelation result A3 of the group interval 3S, performs frequency offset compensation on one of the autocorrelation results, for example, A2 based on the phase difference σ2, obtains the frequency offset compensated A2', and then superimposes the frequency offset compensated A2' and the corresponding other autocorrelation result A3 to obtain the superimposition result SUM2; the receiving end calculates the phase difference σ3 of the autocorrelation result A1 of the group interval 1S and the autocorrelation result A3 of the group interval 3S, performs frequency offset compensation on one of the autocorrelation results, for example, A1 based on the phase difference σ3, obtains the frequency offset compensated A1', and then superimposes the frequency offset compensated A1' and the corresponding other autocorrelation result A3 to obtain the superimposition result SUM3. In this way, in the case of presetting different group intervals, the receiving end can obtain multiple superimposition results through the above steps.

[0160] The superposition process of the autocorrelation result in the wireless signal synchronization method of the dual-mode carrier communication system will be described below in combination with the accompanying drawings.

[0161] Figure 4 is a schematic diagram of the superposition process of the autocorrelation result in the wireless signal synchronization method of the dual-mode carrier communication system provided in some embodiments of the present application. As shown in Figure 4 In the upper branch, the left input data data0'~data8' are multiplied point by point with another group of data conj(data1')~conj(data9'), as shown by the symbol In the lower branch, the left input data data0'~data7' are multiplied point by point with another group of data conj(data2')~conj(data9'), and the point-by-point multiplication and summation sum operation are also performed. After that, the summation result of the lower branch is subjected to a complex conjugate operation again. The result of the branch after the complex conjugate operation is subjected to a frequency offset compensation operation on one hand and a cross-correlation operation with the summation result of the upper branch on the other hand. Based on the summation result of the upper branch, the frequency offset compensated result of the lower branch, and the cross-correlation result of the lower branch and the upper branch, a final summation sum is performed to obtain the correlation value corr.Figure 4 In the present disclosure, "correlation" refers to a cross-correlation calculation, and "compensation" refers to a frequency offset compensation operation based on a phase difference.

[0162] It should be noted that, Figure 4 In the figure, only two autocorrelation results are shown as an example. In some actual embodiments, the autocorrelation results can be autocorrelation results of different group intervals, and the number of autocorrelation results is not limited to two. When there are three or more autocorrelation results, the autocorrelation results can be superimposed according to similar logic, and finally a correlation value reflecting the correlation degree between the multiple groups of autocorrelation results can be obtained.

[0163] In the wireless signal synchronization process, autocorrelation calculation is the core link for extracting signal features and identifying synchronization identifiers. Autocorrelation calculation provides a basis for key links such as synchronization, feature extraction, and interference suppression of wireless signals. In the wireless communication system under the HRF communication protocol, autocorrelation calculation is relied on to achieve frame synchronization of wireless signals and locate the data transmission position of wireless signals. However, in the related art, autocorrelation calculation is usually based on the repeated structure of the STF, and adjacent short symbols are delayed for autocorrelation calculation. This method is significantly affected by noise interference in a low signal-to-noise ratio (SNR) condition, resulting in a sharp decline in synchronization performance.

[0164] In a dual-mode carrier communication system based on the HRF protocol, the sending end will scramble the original data with a scrambling code sequence before transmission. Therefore, the receiving end receives mixed data of the original wireless signal and the scrambling code sequence, and the periodicity, correlation, and other synchronization identifiers of the signal are masked. If the received wireless signal is directly used for synchronization calculation, the subsequent autocorrelation calculation cannot capture a significant peak value, and frame synchronization cannot be achieved. Therefore, according to the scrambling code sequence, each group of data needs to be descrambled to obtain the original wireless signal and the information carried in the signal.

[0165] Based on this, in some embodiments, each group of data is descrambled according to a scrambling code sequence to obtain multiple groups of descrambled data, specifically including: for each sampling point in each group of data to be descrambled, performing point-by-point operation on the sampling point and the scrambling code value at the corresponding position in the predefined scrambling code sequence to obtain the descrambled data of the corresponding group; and performing the above steps on each group of descrambled data to obtain multiple groups of descrambled data.

[0166] The point-by-point operation is a corresponding operation on the sampling point at each position in the data group and the scrambling code value at the same position in the scrambling code sequence, and the point-by-point operation in the descrambling process and the scrambling operation at the sending end are inverse operations of each other, which is used to offset the influence of the scrambling code sequence.

[0167] Specifically, the receiving end reads the scrambling sequence consistent with the sending end, and obtains a plurality of groups of data to be descrambled, wherein the length of each group of data to be descrambled is consistent with the length of the scrambling sequence, ensuring point-by-point matching. Thereafter, the receiving end traverses each group of data to be descrambled, and performs point-by-point operation on each sampling point in the data group and the scrambling value at the corresponding position in the scrambling sequence, to obtain descrambled data corresponding to each group of data to be descrambled. All groups of data to be descrambled are subjected to descrambling operation, and finally a plurality of groups of descrambled data are obtained.

[0168] For example, Figure 5 is a descrambling schematic diagram provided by the present application in some embodiments. As Figure 5 shown, the upper long bar represents data DATA, and the time axis is t. With the reception time t0 of the wireless signal as the reference, frame data matching the length of the predefined scrambling sequence is selected forwardly. At this time, the frame data is divided into 10 data groups, and S is the length of the scrambling sequence. The original data units from left to right are data9~ data0, and the length of the scrambling sequence S is 10 units from left to right, which are -1, -1, -1, -1, 1, 1, -1, -1, -1, and 1. Figure 5 In descrambling operation, which may be one or more of, for example, exclusive OR operation, modulo operation, multiplication operation, etc. The original data units and the corresponding scrambling sequence units are subjected to descrambling operation, and the obtained result is Figure 5 In the scrambling sequence, the 10 data units pointed to by each unit arrow from left to right are data9’~ data0’, i.e., data9’~ data0’ are the data after descrambling. In this way, the descrambling operation of all data groups is completed.

[0169] In the above embodiments, each group of data is subjected to point-by-point descrambling processing according to the scrambling sequence, to obtain a plurality of groups of descrambled data. The sampling points of each group of data are subjected to point-by-point operation with the scrambling values of the predefined scrambling sequence at the corresponding positions, which can effectively restore the original signal characteristics, provide good input for subsequent autocorrelation calculation, and provide a unified signal format for the dual-mode carrier communication system based on the HRF protocol, thereby ensuring the compatibility of the system.

[0170] When extracting frame data, the data amount and the direction of the frame data affect the effect of subsequent descrambling. If the frame data is too much, it is easy to cause redundant calculation, affecting the real-time performance of the system, and if the frame data is too little, the periodicity of the signal cannot be guaranteed. If the frame data is cut back, noise and interference data of other frames may be mistakenly cut as frame data, or the key features of the current frame data may be missed. In addition, if the cut frame data is not matched with the sequence length, there may be remaining unmatched sampling points in the frame data that cannot be descrambled, resulting in residual scrambling codes, and the position alignment relationship of point-by-point operation is broken, and the descrambled signal will introduce additional noise.

[0171] Based on this, in some embodiments, based on the arrival position of the wireless signal frame, frame data matching the predefined scrambling code sequence length is extracted, which mainly includes: based on the arrival position of the wireless signal frame, cutting the received data in the previous direction of the received data as the extracted frame data, and the length of the received data is an integer multiple of the scrambling code sequence length.

[0172] Specifically, the receiving end locates the arrival position of the wireless signal frame, and takes the arrival position as the reference for subsequent cutting operation. Illustratively, the receiving end can locate the positioning position of the wireless signal by identifying the preset synchronization sequence, the preamble.

[0173] After that, the previous direction of the received data is determined, for example, the forward direction can be the opposite direction of the time of data reception, that is, the extension direction of the data obtained earlier than the arrival position is taken as the forward direction. Taking the arrival position as the end of the cutting range, the starting end of the cutting is determined in the previous direction, and the position of the starting end is determined by the cutting length. For the cutting length, the receiving end reads the scrambling code sequence length l , and determines the integer multiple K according to the requirement. The final cutting length is calculated. Finally, the arrival position is cut sampling points in the forward direction, and the data composed of these sampling points is the frame data.

[0174] In the above embodiments, by cutting the sampling point data with a length of an integer multiple of the scrambling code sequence as frame data based on the arrival position of the wireless signal frame, the correspondence between the scrambling code period of the sending end and the descrambling period of the receiving end can be realized, the key features such as periodicity and correlation of the signal are ensured not to be truncated and damaged, and a reliable foundation is provided for subsequent capture of synchronization peak value and analysis of service data through autocorrelation calculation.

[0175] The wireless signal synchronization method of the dual-mode carrier communication system provided in the embodiment of the present application can be executed by the wireless signal synchronization device of the dual-mode carrier communication system.

[0176] The wireless signal synchronization method of the dual-mode carrier communication system provided in the embodiment of the present application can be executed by the wireless signal synchronization device of the dual-mode carrier communication system.

[0177] Figure 6 FIG. 4 is a diagram of the synchronization effect of the wireless signal of the dual-mode carrier communication system in the bandwidth of 40 MHz provided in some embodiments of the present application. Figure 6 As shown in FIG. 4, the horizontal coordinate is the distance from the correct synchronization position, and the value range is about -100 to 150; and the vertical coordinate is the cumulative distribution probability, and the value range is 0 to 1. Figure 6 The solid line curve cdf1 in FIG. 4 represents the original traditional synchronization algorithm, and the dotted line curve cdf5 represents the result after 5 times of accumulation and phase compensation. It can be seen that, compared with cdf1, the curve of cdf5 rises more steeply and is concentrated in the area close to the cumulative distribution probability of 0. When the horizontal coordinate is near 0, cdf5 rapidly rises from a low probability to close to 1, indicating that the deviation distance of most samples is very small, and the synchronization accuracy is high. It is proved that the result after 5 times of accumulation can effectively improve the synchronization performance.

[0178] Figure 7 FIG. 5 is a diagram of the synchronization effect of the wireless signal of the dual-mode carrier communication system in the bandwidth of 200 kHz provided in some embodiments of the present application. Figure 7 As shown in FIG. 5, the horizontal coordinate is the distance from the correct synchronization position, and the value range is -1500 to 1500; and the vertical coordinate is the cumulative distribution probability, and the value range is 0 to 1. Figure 7 In FIG. 5, the solid line cdf1 is the curve without accumulation, and it can be seen that, for the HRF protocol mode with smaller bandwidth, the traditional synchronization algorithm without accumulation has poorer performance. The dotted line curve cdf5 is the result after 5 times of accumulation and phase compensation. The superposition can show more obvious optimization of the synchronization performance. It can be known from the curve result in the figure that the synchronization effect of the synchronization algorithm in the narrow bandwidth condition is poor, while the synchronization after the accumulation algorithm can ensure good synchronization results in different bandwidth modes, verifying the effectiveness and stability of the wireless signal synchronization method of the dual-mode carrier communication system.

[0179] The embodiment of the present application also provides a wireless signal synchronization device of a dual-mode carrier communication system, which is applied to an electronic device.

[0180] Figure 8 Figure 1 is a structural schematic diagram of the wireless signal synchronization device of the dual-mode carrier communication system provided by some embodiments of the present application. Figure 8 As shown in the figure, the wireless signal synchronization device of the dual-mode carrier communication system comprises an extraction module 800, a descrambling module 801, an autocorrelation module 802 and a superposition module 803.

[0181] The extraction module 800 is used for receiving a wireless signal frame and extracting frame data matching a predefined scrambling sequence length based on a sampling point position of the wireless signal frame, wherein the frame data is divided into multiple groups of data.

[0182] The descrambling module 801 is used for performing descrambling processing on each group of data respectively according to a scrambling sequence to obtain multiple groups of descrambled data.

[0183] The autocorrelation module 802 is used for performing autocorrelation calculation on the multiple groups of descrambled data according to a preset autocorrelation number to obtain multiple autocorrelation results.

[0184] The superposition module 803 is used for superimposing the multiple autocorrelation results to obtain a superposition result and determining a frame synchronization position of the wireless signal frame based on the superposition result.

[0185] According to the wireless signal synchronization device of the dual-mode carrier communication system provided by the embodiment of the present application, the frame data matching the scrambling sequence is extracted based on the sampling point position of the wireless signal, which avoids irrelevant data from entering the calculation, reduces the calculation redundancy, divides the frame data into multiple groups of data, facilitates the collaborative verification through the multiple groups of data, avoids the error of a single group of data and influences the subsequent calculation, removes the randomness of the scrambling through the descrambling processing on each group of data, recovers the structure of the data itself, facilitates the subsequent autocorrelation calculation to capture the internal law of the frame and avoids the synchronization misjudgment, adjusts the autocorrelation point number through the preset autocorrelation number, and the multiple groups of descrambled data are calculated multiple times according to the autocorrelation number, which can provide guarantee for the selection of the subsequent autocorrelation peak value, simultaneously covers a reasonable delay range, avoids the difficulty in distinguishing the autocorrelation peak value and the noise energy caused by the insufficient autocorrelation point number, enables the wireless signal to also have a high synchronization success rate when the signal-to-noise ratio is low, superimposes the multiple autocorrelation results after that, enhances the signal-to-noise ratio of the synchronization point peak value of the wireless signal, further weakens the influence of the burst interference, is suitable for the wireless signal synchronization under multiple signal-to-noise ratios, still can guarantee a high synchronization success rate in the application scene of the weak wireless signal and strong interference, and provides a reliable reference for the subsequent other processing of the wireless signal.

[0186] In some embodiments, the self-correlation module is further configured to select a plurality of inter-group intervals based on a total number of the plurality of groups of descrambled data; wherein the number of the inter-group intervals is the same as the preset number of self-correlation times, and the inter-group interval is an integer multiple of the length of the scrambling sequence; and perform a plurality of self-correlation calculations on the plurality of groups of descrambled data according to each inter-group interval, to obtain a plurality of self-correlation results corresponding to the number of self-correlation times.

[0187] In some embodiments, the superposition module is further configured to determine a reference self-correlation result from the plurality of self-correlation results; compensate the remaining self-correlation results in the plurality of self-correlation results based on the reference self-correlation result; superimpose the compensated self-correlation results and the reference self-correlation result to obtain a superimposed result.

[0188] In some embodiments, the superposition module is further configured to, for any self-correlation result from the remaining self-correlation results, perform a cross-correlation calculation on the reference self-correlation result and the self-correlation result to obtain a cross-correlation result; wherein the cross-correlation result is in a complex number form; perform energy normalization processing on the cross-correlation result to obtain a normalized cross-correlation result, and extract a phase value in the normalized cross-correlation result in the complex number form to obtain a phase difference therebetween; and perform phase compensation on the self-correlation result according to the phase difference to obtain a compensated self-correlation result.

[0189] In some embodiments, the self-correlation module is further configured to, for any inter-group interval, set a sliding window with a length equal to the length of the scrambling sequence on the plurality of groups of descrambled data; for a current window, select another window positioned at the inter-group interval from a starting position of the current window, and perform a conjugate multiplication on corresponding sampling points in the two windows in a complex domain to obtain a multiplication result; accumulate the multiplication result in the current window to obtain a single self-correlation value corresponding to the starting position of the current window; repeat the calculation with the sliding of the starting position of the window, and arrange all the single self-correlation values in the current window in a sequence of the starting positions of the windows to form a self-correlation result corresponding to the inter-group interval; and repeat the above calculation for different inter-group intervals to obtain self-correlation results corresponding to the plurality of inter-group intervals respectively.

[0190] In some embodiments, the superposition module is further configured to search for a peak point with the largest amplitude based on the superimposed result; and determine a frame synchronization position of the wireless signal based on a time position corresponding to the peak point, in a case where the peak point satisfies a self-correlation threshold condition.

[0191] In some embodiments, the descrambling module is further configured to, for each sampling point in each group of to-be-descrambled data, perform a point-by-point operation on the sampling point and a scrambling value at a corresponding position in the predefined scrambling sequence to obtain descrambled data of the corresponding group; and perform the above steps on each group of descrambled data to obtain the plurality of groups of descrambled data.

[0192] In some embodiments, the extraction module is further configured to intercept, along the previous direction of receiving the data, the received data with an integer multiple of the length of the scrambling sequence as the extracted frame data based on the arrival position of the wireless signal frame.

[0193] In some embodiments, the apparatus can be an electronic device or a component of an electronic device, such as an integrated circuit or a chip.

[0194] In some embodiments, the apparatus can be an electronic device or a component of an electronic device, such as an integrated circuit or a chip.

[0195] In some embodiments, the apparatus can be an electronic device or a component of an electronic device, such as an integrated circuit or a chip.

[0196] Figure 9 FIG. 1 is a structural schematic diagram of an electronic device according to some embodiments of the present application. Figure 9 As shown in FIG. 1, the electronic device 100 includes a processor 101, a memory 102, and a computer program stored in the memory 102 and executable on the processor 101.

[0197] It should be noted that the electronic device in the embodiments of the present application includes the mobile electronic device and the non-mobile electronic device.

[0198] The present application also provides a non-transitory computer readable storage medium having a computer program stored thereon, wherein the computer program is executable by a processor to implement the processes of the above-mentioned wireless signal synchronization method for a dual-mode carrier communication system.

[0199] The processor is the processor of the electronic device described in the above embodiments. The readable storage medium includes a computer readable storage medium, such as a computer readable only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0200] The present application also provides a computer program product including a computer program executable by a processor to implement the above-mentioned wireless signal synchronization method for a dual-mode carrier communication system.

[0201] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes a computer readable storage medium, such as a computer readable only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0202] The embodiment of the present application further provides a chip, which comprises a processor and a communication interface, the communication interface is coupled with the processor, the processor is used for running programs or instructions to realize each process of the wireless signal synchronization method of the dual-mode carrier communication system and achieve the same technical effects. To avoid repetition, details are not described herein.

[0203] It should be understood that the chip mentioned in the embodiment of the present application can also be referred to as a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0204] It should be noted that in this document, the term "comprising" or "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of additional identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to the order of performing the functions as shown or discussed, but can also include performing the functions in a substantially simultaneous manner or in reverse order, for example, the described method can be performed in an order different from that described, and various steps can also be added, omitted or combined. In addition, the features described with reference to certain examples can be combined in other examples.

[0205] From the above description of the embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment method can be realized by means of software and necessary general hardware platform, of course, it can also be realized by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present application or the parts that contribute to the related art can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk, etc.), and includes a plurality of instructions for making a terminal (which can be a mobile phone, computer, server or network device, etc.) execute the method described in each embodiment of the present application.

[0206] The embodiments of the present application are described above with reference to the accompanying drawings, but the present application is not limited to the above-described specific embodiments, and the above-described specific embodiments are merely illustrative, but not restrictive, and a person of ordinary skill in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, and all of them belong to the protection of the present application.

[0207] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an illustrative embodiment", "an example", "a specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0208] If not specifically stated, all the embodiments and optional embodiments of the present application can be combined to form new technical solutions.

[0209] If not specifically stated, all the technical features and optional technical features of the present application can be combined to form new technical solutions.

[0210] If not specifically stated, all the steps of the present application can be performed in sequence or randomly, and the sequence is preferred. For example, the method comprises steps (a) and (b), which means that the method can comprise steps (a) and (b) performed in sequence, or steps (b) and (a) performed in sequence. For example, it is mentioned that the method can further comprise step (c), which means that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0211] The above is only the preferred embodiment of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for synchronizing wireless signals in a dual-mode carrier communication system, comprising the steps of: The method comprises: receiving a wireless signal frame, and extracting frame data matching a predefined scrambling sequence length based on a sampling point position of the wireless signal frame, the frame data being divided into multiple groups of data; respectively performing descrambling processing on each group of data according to the scrambling sequence to obtain multiple groups of descrambled data; and selecting multiple inter-group intervals based on a total quantity of the multiple groups of descrambled data; wherein the quantity of the inter-group intervals is the same as a preset autocorrelation time, and the inter-group interval is an integer multiple of the scrambling sequence length; for each inter-group interval, performing autocorrelation operation on one group of descrambled data and another group of descrambled data to obtain an autocorrelation result corresponding to each inter-group interval; wherein the interval between the two groups of data is the inter-group interval currently used; after performing autocorrelation calculation on the multiple groups of descrambled data with the same inter-group interval, taking an average value or a merged value of each group of autocorrelation results as a final autocorrelation result of the corresponding inter-group interval; performing autocorrelation calculation on the multiple groups of descrambled data according to a preset autocorrelation time to obtain multiple autocorrelation results; superimposing the multiple autocorrelation results to obtain a superimposed result, and determining a frame synchronization position of the wireless signal frame based on the superimposed result.

2. The method of claim 1, wherein, The superimposing the multiple autocorrelation results to obtain a superimposed result comprises: determining a reference autocorrelation result in the multiple autocorrelation results; based on the reference autocorrelation result, compensating the remaining autocorrelation results in the multiple autocorrelation results, and superimposing the compensated autocorrelation results and the reference autocorrelation result to obtain a superimposed result.

3. The method of claim 2, wherein, The compensating the remaining autocorrelation results in the multiple autocorrelation results based on the reference autocorrelation result comprises: for any autocorrelation result in the remaining autocorrelation results, performing cross-correlation calculation on the reference autocorrelation result and the autocorrelation result to obtain a cross-correlation result; wherein the cross-correlation result is in a complex number form; performing energy normalization processing on the cross-correlation result to obtain a normalized cross-correlation result, and extracting a phase value in the complex number form of the normalized cross-correlation result to obtain a phase difference therebetween; performing phase compensation on the autocorrelation result according to the phase difference to obtain a compensated autocorrelation result.

4. The method of claim 1, wherein, The performing autocorrelation calculation on the multiple groups of descrambled data according to a preset autocorrelation time to obtain multiple autocorrelation results comprises: for any inter-group interval, setting a sliding window with a length equal to the scrambling sequence length on the multiple groups of descrambled data; for the current window, selecting another window positioned from a starting position of the current window by the inter-group interval, and performing conjugate multiplication on corresponding sampling points in the two windows in a complex domain to obtain a multiplication result; performing accumulation on the multiplication result in the current window to obtain a single autocorrelation value corresponding to the starting position of the current window; with the sliding of the window starting position, repeating the calculation, and arranging all single autocorrelation values in the current window in a sequence of window starting positions to form an autocorrelation result corresponding to the inter-group interval; and The above calculation is repeated for different inter-group intervals to obtain autocorrelation results corresponding to a plurality of inter-group intervals respectively.

5. The method according to any one of claims 1 to 4, characterized in that, The method further includes: searching for a peak point with a maximum amplitude based on the superposition result; in a case where the peak point satisfies an autocorrelation threshold condition, determining a frame synchronization position of the wireless signal based on a time position corresponding to the peak point.

6. The method of claim 1, wherein, The method further includes: performing point-by-point operation on each sampling point in each group of data to be descrambled and a scrambling value at a corresponding position in a predefined scrambling sequence to obtain descrambled data of the corresponding group; performing the above operation on each group of descrambled data to obtain a plurality of groups of descrambled data.

7. The method according to claim 1 or 6, characterized in that, The method further includes: based on the sampling point position of the wireless signal frame, intercepting received data with an integer multiple of the length of the scrambling sequence as the extracted frame data in a previous direction of the received data.

8. A wireless signal synchronization device for a dual-mode carrier communication system, characterized in that, The apparatus includes: an extraction module configured to receive a wireless signal frame and extract frame data matching a length of a predefined scrambling sequence based on a sampling point position of the wireless signal frame, the frame data being divided into a plurality of groups of data; a descrambling module configured to perform descrambling on each group of data based on the scrambling sequence to obtain a plurality of groups of descrambled data, select a plurality of inter-group intervals based on a total number of the plurality of groups of descrambled data, wherein the number of the inter-group intervals is the same as a preset autocorrelation number, and the inter-group intervals are integer multiples of the length of the scrambling sequence; an autocorrelation module configured to perform autocorrelation operation on one group of descrambled data and another group of descrambled data for each inter-group interval to obtain an autocorrelation result corresponding to each inter-group interval, wherein the interval between the two groups of data is the currently used inter-group interval, and the average or combined value of the autocorrelation results of each group is taken as the final autocorrelation result of the corresponding inter-group interval after performing autocorrelation calculation on the plurality of groups of descrambled data with the same inter-group interval, and performing autocorrelation calculation on the plurality of groups of descrambled data according to the preset autocorrelation number to obtain a plurality of autocorrelation results; a superposition module configured to superimpose the plurality of autocorrelation results to obtain a superposition result, and determine a frame synchronization position of the wireless signal frame based on the superposition result.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor implements the wireless signal synchronization method of the dual-mode carrier communication system when executing the computer program. The processor implements the wireless signal synchronization method of the dual-mode carrier communication system when executing the computer program.

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