Method for synchronizing hrf signals in dual-mode communication chip

Abstract

The application discloses a HRF signal synchronization method in a dual-mode communication chip, and belongs to the technical field of communication. The HRF signal synchronization method in the dual-mode communication chip comprises the following steps: performing frequency offset pre-compensation on a received signal to obtain a plurality of frequency offset compensation signals; obtaining a cross-correlation result corresponding to each compensation signal respectively, and buffering the cross-correlation result corresponding to each compensation signal into a corresponding buffer window respectively; determining a relative threshold value used for restraining autocorrelation peak judgment under a current signal environment based on the cross-correlation result in each buffer window; determining an autocorrelation result maximum value in the autocorrelation result corresponding to each compensation signal; and determining a synchronization position of the received signal based on a signal position corresponding to a frequency offset compensation signal generating the autocorrelation result maximum value in the case that the autocorrelation result maximum value is greater than a preset autocorrelation threshold value and greater than the relative threshold value. The application realizes high-precision wireless signal synchronization.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, and in particular relates to a method for synchronizing HRF signals in a dual-mode communication chip. Background Technology

[0002] With the integration and development of power line communication (PLC) and wireless communication technologies, dual-mode communication chips are gradually being widely used in fields such as smart grids, smart homes, and the Internet of Things.

[0003] High-speed radio frequency (HRF) is a high-data-rate communication protocol applied to dual-mode communication chips. It supports multiple frequency band configurations and employs structures such as preamble symbols and short training fields (STFs) for signal synchronization and channel estimation. This enables accurate and reliable signal frame synchronization in complex power line channels and multipath fading environments, making it one of the key technologies for ensuring chip communication performance.

[0004] In related technologies, a common approach is to use autocorrelation to synchronize wireless signals. However, when the subcarrier spacing of the wireless signal is narrow, the frequency offset estimation range of the autocorrelation method can only cover part of the subcarrier spacing, making it difficult to accurately estimate the frequency offset of the wireless signal, resulting in poor signal synchronization. If frequency offset pre-compensation is used to cover the possible frequency offset range, and then synchronization is performed based on a preset fixed threshold, the correlation value at the asynchronous position may increase and exceed the preset fixed threshold, causing the synchronization process to be locked prematurely, missing the true signal synchronization position, and thus affecting the synchronization accuracy and communication reliability of the dual-mode communication chip. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes an HRF signal synchronization method in a dual-mode communication chip to achieve high-precision wireless signal synchronization.

[0006] In a first aspect, the present invention provides a method for synchronizing HRF signals in a dual-mode communication chip, the method comprising: Frequency offset pre-compensation is performed on the received signal to obtain multiple frequency offset compensated signals; Cross-correlation calculations are performed on each frequency offset compensation signal to obtain the cross-correlation results for each compensation signal, and the cross-correlation results for each compensation signal are cached in their respective cache windows. Based on the cross-correlation results in each buffer window, a relative threshold for constraining the autocorrelation peak determination is determined under the current signal environment; the relative threshold changes dynamically with the changes in the cross-correlation results. Autocorrelation calculations are performed on the cross-correlation results corresponding to each compensation signal to obtain the autocorrelation results corresponding to each compensation signal, and the maximum value of the autocorrelation results corresponding to each compensation signal is determined. If the maximum value of the autocorrelation result is greater than the preset autocorrelation threshold and greater than the relative threshold, the synchronization position of the received signal is determined based on the signal position in the frequency offset compensation signal that generates the maximum value of the autocorrelation result.

[0007] According to one embodiment of the present invention, a relative threshold for constraining autocorrelation peak determination under the current signal environment is determined based on the cross-correlation results in each buffer window. Specifically, this includes: determining a threshold coefficient based on the communication frequency band of the received signal, and determining a cross-correlation reference value based on the cross-correlation results in each buffer window; and determining a relative threshold based on the threshold coefficient and the cross-correlation reference value.

[0008] According to one embodiment of the present invention, the relative threshold is the product of the threshold coefficient and the square of the cross-correlation reference value.

[0009] According to one embodiment of the present invention, the cross-correlation benchmark value is the maximum value among the cross-correlation results in each buffer window; or, the cross-correlation benchmark value is the maximum value among the cross-correlation results of the current sampling point in each buffer window.

[0010] According to one embodiment of the present invention, the threshold coefficient is positively correlated with the number of repeating sequences in the STF frame of the received signal.

[0011] According to one embodiment of the present invention, determining the synchronization position of the received signal based on the signal position corresponding to the frequency offset compensation signal that generates the maximum autocorrelation result specifically includes: when the maximum autocorrelation value is greater than a preset autocorrelation threshold and greater than a relative threshold, determining the signal position corresponding to the frequency offset compensation signal that generates the maximum autocorrelation result as a candidate synchronization position; continuing to detect autocorrelation results within a preset synchronization range after the candidate synchronization position; if no autocorrelation result greater than the maximum autocorrelation value is detected, determining the candidate synchronization position as the synchronization position of the received signal; if an autocorrelation result greater than the maximum autocorrelation value is detected, updating the candidate synchronization position based on the signal position corresponding to the subsequent autocorrelation result, and determining the synchronization position of the received signal based on the updated candidate synchronization position.

[0012] According to one embodiment of the present invention, the relative threshold is greater than a preset autocorrelation threshold and the degree of difference is related to the signal-to-noise ratio of the current signal environment.

[0013] According to one embodiment of the present invention, the length of the buffer window is associated with the communication frequency band of the received signal and is positively correlated with the number of sampling points in the STF frame.

[0014] According to one embodiment of the present invention, the number of multiple frequency offset compensation signals is less than or equal to 10.

[0015] According to one embodiment of the present invention, frequency offset pre-compensation is performed on the received signal to obtain multiple frequency offset compensation signals, specifically including: dividing the frequency offset range into several frequency offset assumption intervals based on the maximum allowable residual frequency offset range, each frequency offset assumption interval corresponding to a frequency offset assumption; performing frequency offset pre-compensation on the received signal according to each frequency offset assumption interval to obtain multiple frequency offset compensation signals.

[0016] In a second aspect, the present invention provides an HRF signal synchronization device in a dual-mode communication chip, the device comprising: The compensation module is used to perform frequency offset pre-compensation on the received signal to obtain multiple frequency offset compensation signals; The caching module is used to perform cross-correlation calculations on each frequency offset compensation signal, obtain the cross-correlation results corresponding to each compensation signal, and cache the cross-correlation results corresponding to each compensation signal into their respective cache windows. The determination module is used to determine the relative threshold for constraining the autocorrelation peak determination under the current signal environment based on the cross-correlation results in each buffer window; the relative threshold changes dynamically as the cross-correlation results change; The autocorrelation module is used to perform autocorrelation calculations on the cross-correlation results corresponding to each compensation signal, obtain the autocorrelation results corresponding to each compensation signal, and determine the maximum value of the autocorrelation results corresponding to each compensation signal. The synchronization module is used to determine the synchronization position of the received signal based on the signal position in the frequency offset compensation signal that generates the maximum value of the autocorrelation result when the maximum value of the autocorrelation result is greater than a preset autocorrelation threshold and greater than a relative threshold.

[0017] Thirdly, the present invention provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the HRF signal synchronization method in the dual-mode communication chip as described in the first aspect above.

[0018] Fourthly, the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the HRF signal synchronization method in the dual-mode communication chip as described in the first aspect above.

[0019] Fifthly, the present invention provides a chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the HRF signal synchronization method in the dual-mode communication chip as described in the first aspect.

[0020] In a sixth aspect, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the HRF signal synchronization method in a dual-mode communication chip as described in the first aspect above.

[0021] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: By performing cross-correlation calculations on multiple frequency offset compensation signals obtained through frequency offset pre-compensation of the received signal, the cross-correlation results corresponding to each compensation signal are obtained. This enhances the matching response between the signal and the local sequence within a certain frequency offset range, enabling the cross-correlation results to form a significant peak at the true synchronization position, thus achieving enhanced extraction of effective signal components in the received signal. Subsequently, the cross-correlation results corresponding to each compensation signal are cached into their respective cache windows. Based on the cross-correlation results in each cache window, a relative threshold for constraining autocorrelation peak determination under the current signal environment can be determined. This allows the cross-correlation results within the cache window to be dynamically updated, thereby determining a cross-correlation benchmark value that changes with the real-time signal based on the cross-correlation results in the current window, and generating a relative threshold accordingly. This achieves dynamic correlation between synchronization decision and the current signal. Since the relative threshold changes synchronously with the update of the cache window, it always reflects the best matching degree within the most recent signal window, effectively avoiding the problems caused by multi-channel pre-compensation. The risk of misjudging a cross-correlation value abnormally high at asynchronous positions as a synchronization peak is significantly reduced, thus significantly improving the accuracy of synchronization position determination. Subsequently, autocorrelation calculations are performed on the cross-correlation results corresponding to each compensation signal. Based on the obtained autocorrelation results for each compensation signal, the maximum value of the autocorrelation result is determined. This allows for the superposition of effective signal energy while suppressing random noise, resulting in an autocorrelation result for the true synchronization position being significantly higher than that for the asynchronous position, achieving separation of correlation peaks from noise. Finally, when the maximum value of the autocorrelation result is greater than a preset autocorrelation threshold and a relative threshold, the synchronization position of the received signal is determined based on the signal position corresponding to the frequency offset compensation signal that generated the maximum autocorrelation result. The preset autocorrelation threshold can be used to remove low-energy noise, and a dynamic relative threshold can be used to filter out false peaks at asynchronous positions under high signal-to-noise ratio (SNR) conditions. This improves the success rate of low SNR detection while significantly reducing the probability of false synchronization in high SNR environments, achieving high-precision wireless signal synchronization.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of spurious peaks in the autocorrelation results provided in some embodiments of the present invention; Figure 2 This is a flowchart illustrating the HRF signal synchronization method in a dual-mode communication chip provided in some embodiments of the present invention; Figure 3 This is a schematic diagram of STF frames corresponding to different communication frequency bands in the dual-mode communication chip provided in some embodiments of the present invention; Figure 4 This is a schematic diagram of the polarity arrangement and synchronization status of short training symbols in the Option3 communication band provided in some embodiments of the present invention; Figure 5 This is a schematic diagram of the HRF signal synchronization device in a dual-mode communication chip provided in some embodiments of the present invention; Figure 6 This is a schematic diagram of the structure of an electronic device provided in some embodiments of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0025] The terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0026] In dual-mode communication chips, the HRF protocol requires high synchronization accuracy for wireless signals. When the signal-to-noise ratio is low in the application scenario, a large synchronization deviation can easily lead to wireless signal synchronization failure, resulting in the inability to transmit data normally, causing communication system disconnection and data loss. Affected by various complex factors such as crystal oscillator accuracy limitations, ambient temperature changes, and electromagnetic interference, the received signal is highly susceptible to frequency shifts, leading to communication frame loss or synchronization failure, severely restricting further improvements in chip performance.

[0027] In related technologies, wireless signal synchronization is typically based on autocorrelation calculation using the STF (Short Symbol Transmission Frame). This involves extracting the STF from the received wireless signal frame, utilizing the periodic structure of short symbols, and employing autocorrelation calculation to detect synchronization peaks, thereby determining the start position of the wireless signal frame. However, in narrow bandwidth scenarios, the STF method suffers from limitations in frequency offset estimation. In narrow bandwidth environments, the STF duration is short, and the spacing between adjacent subcarriers is small. Autocorrelation-based schemes can only estimate the frequency offset of an incomplete subcarrier spacing, easily leading to missed autocorrelation peaks and making wireless signal synchronization difficult.

[0028] Building upon this, other related technologies have further introduced multi-channel frequency offset pre-compensation mechanisms to overcome the impact of frequency offset. Specifically, the received signal is first pre-compensated for multiple frequencies to obtain multiple compensated signals; then, cross-correlation and autocorrelation calculations are performed on each compensated signal to achieve signal synchronization.

[0029] However, during their research on the synchronization of wireless signals in dual-mode communication chips, the inventors discovered that the above method still carries the risk of missynchronization. Figure 1 This is a schematic diagram of spurious peaks in the autocorrelation results provided in some embodiments of the present invention. For example... Figure 1 As shown, the horizontal axis represents the sampling point location, and the vertical axis represents the autocorrelation value amplitude. Figure 1 The image shows the autocorrelation curves obtained after cross-correlation and autocorrelation calculations for a specific frequency offset compensation signal. The solid black arrows indicate the location of the true synchronization peak, while the dashed black arrows indicate the locations of false peaks caused by improper multi-channel frequency offset pre-compensation and fixed threshold settings. Although the autocorrelation value of the false peaks exceeds the preset autocorrelation threshold, the corresponding signal location is not the true frame start point.

[0030] The reason for this situation is that multi-channel frequency offset pre-compensation makes the compensation results of different channels independent, and each channel performs cross-correlation and autocorrelation calculations. At asynchronous positions, the autocorrelation value of one or more channels after compensation may unexpectedly increase. When the selected maximum value exceeds the autocorrelation threshold, it is misjudged as a candidate synchronization position. On the other hand, to balance high and low signal-to-noise ratio (SNR) environments, the autocorrelation threshold is usually set relatively small. At low SNR, a smaller threshold helps detect synchronization signals even under strong noise interference; however, at high SNR, signal characteristics are obvious, and a smaller threshold can cause a large number of asynchronous positions to also meet the threshold condition, leading to frequent misjudgments. Therefore, even with multi-channel frequency offset pre-compensation and a combination of cross-correlation and autocorrelation, the problem of misjudging asynchronous positions as synchronization positions can still occur, directly affecting synchronization accuracy and communication reliability.

[0031] In view of this, embodiments of the present invention provide an HRF signal synchronization method in a dual-mode communication chip, aiming to solve the problem of misjudgment of synchronization position caused by the poor adaptability of fixed thresholds to different signal environments and the introduction of false peaks by multi-path pre-compensation; by sliding the cross-correlation results into a buffer and updating the relative threshold based on the cross-correlation results within the buffer window, the dynamic relative threshold and the preset fixed threshold are used to jointly constrain the autocorrelation peak decision, thereby improving the success rate of low signal-to-noise ratio detection while significantly reducing the probability of missynchronization in high signal-to-noise ratio environments, and achieving high-precision wireless signal synchronization.

[0032] The HRF signal synchronization method in the dual-mode communication chip provided by the present invention will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0033] The HRF signal synchronization method in a dual-mode communication chip provided in this invention can be applied to a dual-mode communication chip or system including a signal transmitting device and a signal receiving device. The signal transmitting device is used to transmit signals, and the signal receiving device enters a signal synchronization state after receiving the signal from the signal transmitting device, so as to extract key data from the subsequent signal.

[0034] Furthermore, the signal transmitting and receiving devices can be, for example, electronic devices, such as power line communication terminals, concentrator devices, smart meters, communication module embedded devices, or communication test terminals. Alternatively, the electronic devices can also be devices with computing capabilities or intelligent robots to perform the signal acquisition, processing, and synchronization steps in this invention.

[0035] The HRF signal synchronization method in the dual-mode communication chip provided by this invention can be implemented by a signal receiving device or a functional module or entity in the signal receiving device that can implement the method.

[0036] The following description uses a signal receiving device as an example to illustrate the HRF signal synchronization method in a dual-mode communication chip provided in this embodiment of the invention.

[0037] Figure 2 This is a flowchart illustrating the HRF signal synchronization method in a dual-mode communication chip provided in some embodiments of the present invention. For example... Figure 2 As shown, the HRF signal synchronization method in this dual-mode communication chip includes steps 210 to 250.

[0038] Step 210: Perform frequency offset pre-compensation on the received signal to obtain multiple frequency offset compensation signals.

[0039] Frequency offset pre-compensation refers to the process of applying reverse phase rotation to the received signal according to multiple preset frequency offset assumptions, in order to offset or reduce the impact of frequency offset caused by factors such as local oscillator frequency error, temperature drift, and Doppler effect on subsequent related calculations.

[0040] In this embodiment of the invention, the signal receiving device first divides multiple frequency offset assumption intervals according to the maximum residual frequency offset range allowed by the communication protocol, with each interval corresponding to a frequency offset assumption value; then, based on each frequency offset assumption value, the original received signal is processed by reverse phase rotation compensation and other processes to obtain multiple frequency offset compensation signals equal to the number of frequency offset assumptions.

[0041] In some implementations, the signal receiving device can dynamically adjust the number and range of frequency offset assumption intervals based on the quality of the current channel environment. For example, when the signal-to-noise ratio is high, since the actual frequency offset fluctuation is small, fewer frequency offset assumption intervals can be used to reduce computational overhead; when the signal-to-noise ratio is low, the actual frequency offset may fluctuate more due to noise interference, so the number of frequency offset assumption intervals can be increased or their coverage expanded to effectively compensate for the true frequency offset value.

[0042] In other implementations, the frequency offset assumption value is not limited to the center frequency of each interval. The signal receiving device can also set it in a non-uniform distribution manner according to the channel statistical characteristics or historical frequency offset estimation results. For example, a denser assumption value can be set in the area where the frequency offset is more likely to occur in order to improve the frequency offset compensation accuracy.

[0043] Step 220: Perform cross-correlation calculations on each frequency offset compensation signal to obtain the cross-correlation results for each compensation signal, and cache the cross-correlation results for each compensation signal into their respective cache windows.

[0044] Cross-correlation calculation refers to performing a sliding matching operation between the sampling point sequence of the frequency offset compensation signal and the reference sequence (such as the short training symbol sequence in the STF frame) stored locally at the signal receiver. That is, for each alignment position, the complex numbers of the corresponding points of the two sequences are multiplied and accumulated. The accumulated value can reflect the similarity between the signal at that position and the reference sequence. This accumulated value is called the cross-correlation result.

[0045] A buffer window is a storage queue or window of fixed length allocated for the cross-correlation results corresponding to each compensation signal.

[0046] For example, the cache window can adopt a first-in-first-out sliding storage structure, where newly generated cross-correlation results are written to the tail of the queue, and when the queue is full, the earliest stored cross-correlation results are removed, so that the cache window always stores cross-correlation results from the most recent period.

[0047] The signal receiving device first acquires a sequence of sampling points of the same length as the local reference sequence for each frequency offset compensation signal, and calculates the cross-correlation result corresponding to each position, forming a cross-correlation result sequence for that frequency offset compensation signal. Then, the signal receiving device writes multiple cross-correlation results from each channel into a buffer window allocated to that channel, according to the signal's chronological order. When a new cross-correlation result is generated, it is stored at the end of the buffer window; if the buffer window is full, the old cross-correlation result at the beginning of the buffer window is discarded, ensuring that the buffer window always stores a fixed number of cross-correlation results.

[0048] In some implementations, the signal receiving device can make the length of the buffer window related to the total number of STF frame sampling points in the communication frequency band where the received signal is located, so that different communication frequency bands correspond to different buffer window lengths.

[0049] In other implementations, the signal receiving device can configure the buffer window length according to the system processing capacity or synchronization accuracy requirements.

[0050] Step 230: Based on the cross-correlation results in each buffer window, determine the relative threshold used to constrain the autocorrelation peak determination under the current signal environment; the relative threshold changes dynamically with the change of the cross-correlation results.

[0051] The relative threshold refers to the decision threshold calculated based on the actual cross-correlation results stored in the buffer window under the current signal environment. It is used to compare with the autocorrelation peak to determine whether it is the true signal synchronization position.

[0052] The signal receiving device iterates through the cross-correlation results stored in each buffer window and determines the relative threshold used to constrain the autocorrelation peak determination based on these cross-correlation results. It should be noted that since the cross-correlation results in the buffer window are continuously updated as new cross-correlation results are written and old cross-correlation results are removed, the set of cross-correlation results stored in the buffer window changes in real time. Therefore, the relative threshold also changes dynamically to always adapt to the current signal environment.

[0053] The signal receiving device uses the obtained relative threshold as a criterion or limiting condition for determining the validity of the autocorrelation peak. In some embodiments, when making a synchronization decision on the autocorrelation result, the signal receiving device compares the relative threshold with the autocorrelation peak. Only when a preset relationship is met (e.g., the autocorrelation peak is greater than the relative threshold) is the signal position corresponding to the autocorrelation peak considered a valid synchronization position; otherwise, the autocorrelation peak is considered insufficient as a valid basis for synchronization decision, and is thus excluded or the search continues. In other words, the relative threshold plays a role in filtering and limiting the autocorrelation peak.

[0054] In some implementations, the signal receiving device traverses the cross-correlation results in each buffer window and determines a cross-correlation reference value from these cross-correlation results; for example, the cross-correlation reference value may be the maximum cross-correlation value of the cross-correlation results in a single buffer window, or it may be the maximum value among all cross-correlation results in each buffer window.

[0055] In other implementations, the signal receiving device may also multiply the cross-correlation reference value by a preset coefficient and use the result as a relative threshold.

[0056] Step 240: Perform autocorrelation calculation on the cross-correlation results corresponding to each compensation signal to obtain the autocorrelation results corresponding to each compensation signal, and determine the maximum value of the autocorrelation results corresponding to each compensation signal.

[0057] Autocorrelation calculation refers to the process by which a signal receiving device performs complex multiplication and successive summation of two cross-correlation results separated by a preset symbol interval in the same cross-correlation result, in order to enhance the effective signal energy and suppress random noise by utilizing the repetitiveness of symbols in the STF frame. For example, the preset symbol interval can be, for instance, the length of a short training symbol, and each value in the calculated numerical sequence is the autocorrelation result.

[0058] The signal receiving device performs autocorrelation calculations on the cross-correlation results corresponding to each compensated signal, generating the corresponding autocorrelation result for that signal. Then, among the autocorrelation results corresponding to each compensated signal, the one with the largest autocorrelation result is determined as the maximum autocorrelation result.

[0059] In some implementations, for each cross-correlation result sequence, the signal receiving device calculates the complex product of the cross-correlation value at the current sampling point and the cross-correlation value after that sampling point that is separated by a short training symbol length, to obtain the autocorrelation result corresponding to the current sampling point. The calculation is performed sequentially by sampling point to form the autocorrelation result sequence for that path. Then, the autocorrelation result with the largest value among all autocorrelation sequences is determined as the maximum autocorrelation result.

[0060] In other implementations, the signal receiving device can dynamically select the symbol interval used for autocorrelation calculation based on the signal-to-noise ratio (SNR) estimation results of the current signal environment. For example, when the SNR is high, a shorter interval (such as half a short training symbol) can be used to enhance robustness to frequency offset; when the SNR is low, a standard short training symbol interval can be used to maximize the coherent accumulation gain of the signal.

[0061] Step 250: When the maximum value of the autocorrelation result is greater than the preset autocorrelation threshold and greater than the relative threshold, determine the synchronization position of the received signal based on the signal position in the frequency offset compensation signal that generates the maximum value of the autocorrelation result.

[0062] The preset autocorrelation threshold refers to a fixed value threshold set in advance to filter out autocorrelation peaks with sufficiently high energy to eliminate low-energy noise interference. The signal position in the frequency offset compensation signal that generates the maximum autocorrelation result refers to the sampling point index or time offset of that maximum value in the original received signal.

[0063] The signal receiving device first obtains the maximum value of the autocorrelation result determined in step 240, and determines the corresponding frequency offset compensation signal and the signal position corresponding to the maximum value of the autocorrelation result. In some embodiments, the signal receiving device compares the maximum value of the autocorrelation result with a preset autocorrelation threshold and a relative threshold corresponding to the path, respectively. When the maximum value of the autocorrelation result is greater than both the preset autocorrelation threshold and the relative threshold, the signal receiving device determines the signal position corresponding to the maximum value of the autocorrelation result as the synchronization position of the received signal. Otherwise, the signal receiving device determines that the current candidate position is invalid and continues to search for a new signal position.

[0064] Through the aforementioned dual threshold decision, the signal receiving device can improve the detection success rate of the synchronization signal by relying on the preset autocorrelation threshold in a low signal-to-noise ratio environment, while eliminating false peaks caused by asynchronous positions based on the dynamic relative threshold in a high signal-to-noise ratio environment, thereby accurately locking the true signal synchronization position.

[0065] In some implementations, after the maximum value of the autocorrelation result is greater than both a preset autocorrelation threshold and a relative threshold, the signal receiving device continues to monitor the autocorrelation result within a preset time window. If no larger autocorrelation value appears within this window, the synchronization position is confirmed, thereby further enhancing the robustness of the signal synchronization position determination.

[0066] In other implementations, the preset autocorrelation threshold can be fixedly configured according to the communication protocol or chip design parameters, while the relative threshold is calculated in real time from the cross-correlation results within the cache window. The two are independent and complementary, and together constitute the dual threshold conditions for synchronous decision-making.

[0067] According to the HRF signal synchronization method in the dual-mode communication chip provided by the present invention, cross-correlation calculation is performed on multiple frequency offset compensation signals obtained by frequency offset pre-compensation of the received signal to obtain the cross-correlation results corresponding to each compensation signal. This can enhance the matching response between the signal and the local sequence within a certain frequency offset range, thereby enabling the cross-correlation results to form a significant peak at the true synchronization position, thus achieving enhanced extraction of effective signal components in the received signal. Subsequently, the cross-correlation results corresponding to each compensation signal are cached into their respective cache windows. Based on the cross-correlation results in each cache window, a relative threshold for constraining the autocorrelation peak determination under the current signal environment can be determined. This allows the cross-correlation results in the cache windows to be dynamically updated, thereby determining a cross-correlation benchmark value that changes with the real-time signal based on the cross-correlation results in the current window, and generating a relative threshold accordingly. This achieves dynamic correlation between synchronization decision and the current signal. Since the relative threshold changes synchronously with the update of the cache window, it can always reflect the best matching degree within the most recent signal window. This approach effectively avoids the risk of misjudging synchronization peaks due to abnormally increased cross-correlation values ​​at asynchronous positions caused by multi-path pre-compensation, thus significantly improving the accuracy of synchronization position determination. Subsequently, autocorrelation calculations are performed on the cross-correlation results corresponding to each compensation signal. Based on the obtained autocorrelation results for each compensation signal, the maximum value of the autocorrelation result is determined. This allows for the superposition of effective signal energy while suppressing random noise, resulting in a significantly higher autocorrelation result for the true synchronization position compared to the asynchronous position, achieving separation of correlation peaks from noise. Finally, when the maximum value of the autocorrelation result is greater than a preset autocorrelation threshold and a relative threshold, the synchronization position of the received signal is determined based on the signal position corresponding to the frequency offset compensation signal that generates the maximum autocorrelation result. The preset autocorrelation threshold can be used to remove low-energy noise, and a dynamic relative threshold can be used to filter out false peaks at asynchronous positions under high signal-to-noise ratio (SNR) conditions. This improves the success rate of low SNR detection while significantly reducing the probability of false synchronization in high SNR environments, achieving high-precision wireless signal synchronization.

[0068] In some embodiments, the relative threshold is greater than a preset autocorrelation threshold and the degree of difference is related to the signal-to-noise ratio of the current signal environment.

[0069] In feasible implementations, the signal-to-noise ratio (SNR) typically refers to the ratio of effective signal energy to noise energy in the received signal, used to characterize the quality of the current signal environment. Generally, the higher the SNR, the clearer the signal; the lower the SNR, the more severe the signal contamination by noise.

[0070] When calculating the relative threshold, the signal receiving device simultaneously acquires the signal-to-noise ratio (SNR) of the current signal environment (e.g., it can be estimated from the preamble of the received signal). Then, with the relative threshold set to be greater than a preset autocorrelation threshold, a preset autocorrelation threshold is further set based on the relationship between the SNR and the difference between the relative threshold and the preset autocorrelation threshold.

[0071] It should be noted that the preset autocorrelation threshold is a fixed threshold, primarily set to consider the detection success rate in low signal-to-noise ratio (SNR) environments, and is typically set to a low value. In low SNR environments, the energy of the true synchronization peak may only be slightly higher than the noise, and a lower threshold can prevent the signal from being missed. However, in high SNR environments, the multi-channel frequency offset pre-compensation mechanism can unexpectedly increase the cross-correlation and autocorrelation values ​​at asynchronous positions. These increased false peaks are also prone to exceeding the lower preset threshold. Relying solely on the preset threshold for decision-making will lead to a large number of false synchronizations.

[0072] Building upon this, the relative threshold is introduced to provide a more stringent threshold under high signal-to-noise ratio (SNR) conditions. Since the relative threshold is dynamically calculated based on the cross-correlation results within the current buffer window, it reflects the actual matching degree under the current signal environment. Setting the relative threshold to be greater than the preset autocorrelation threshold ensures that only when the autocorrelation peak not only exceeds the basic energy threshold (preset threshold) but also further exceeds a higher threshold proportional to the current signal strength can it be considered a true synchronization position. Therefore, false peaks that exceed the preset threshold but are far below the true peak energy under high SNR conditions will be effectively filtered out by the relative threshold. Simultaneously, the true peak energy is lower under low SNR conditions, and the relative threshold will also decrease accordingly (because the cross-correlation baseline value becomes smaller), thus preventing an excessively high decision threshold.

[0073] Furthermore, the difference between the relative threshold and the preset autocorrelation threshold essentially reflects the energy separation between true and false peaks in the current signal environment. The higher the signal-to-noise ratio (SNR), the larger the cross-correlation value at the true synchronization location. This is because the signal correlation is strong and the noise is weak, while the cross-correlation value at the false peak may also increase, but its increase is usually much smaller than that at the true peak. Therefore, the relative difference between true and false peaks is amplified at high SNR.

[0074] In the above embodiments, the difference between the relative threshold and the preset autocorrelation threshold is correlated with the signal-to-noise ratio of the current signal environment. Through this correlation, the difference between the decision thresholds can adaptively widen as the signal quality improves, thereby effectively shielding false peaks in a high signal-to-noise ratio environment and avoiding missed detections in a low signal-to-noise ratio environment, achieving optimal synchronous decision across the entire signal-to-noise ratio range.

[0075] In practical applications, dual-mode communication chips support multiple communication frequency bands (such as Option1, Option2, Option3, etc.). The STF frame structures corresponding to different frequency bands are different, and the number of short training symbols and the total number of sampling points are also different. If a fixed-length buffer window is used, the window may be too short to accommodate the complete STF frame information, affecting the accuracy of the relative threshold; or the window may be too long, causing unnecessary storage overhead and computational delay.

[0076] Figure 3 This is a schematic diagram of STF frames corresponding to different communication frequency bands in a dual-mode communication chip provided in some embodiments of the present invention. For example... Figure 3 As shown, different communication frequency bands (Option1, Option2, Option3) correspond to STF frames with different structures. Each STF frame consists of multiple short training symbols (each symbol denoted as S), and each S symbol comprises 16 sampling points. Figure 3 The text illustrates the different polarities of the S symbol, including both positive S and negative -S. The polarity arrangement of the S symbol typically alternates according to a pattern specified by the communication protocol, used to indicate the start of a frame and symbol boundaries. Figure 3 It is known that the total number of sampling points in STF frames varies across different communication frequency bands. Therefore, the length of the associated cross-correlation buffer window should be adjusted accordingly. The more total sampling points there are, the longer the window should be to store the cross-correlation results that fully cover the STF frame. Conversely, if a uniform and fixed window length is used, there may be insufficient information in communication frequency bands with a large number of total sampling points, or resource waste in frequency bands with a small number of total sampling points.

[0077] Based on this, in some embodiments, the length of the buffer window is associated with the communication frequency band of the received signal and is positively correlated with the number of sampling points in the STF frame.

[0078] The signal receiving device first determines the frequency band used for the current communication. In some implementations, the signal receiving device can obtain this information, for example, based on the communication protocol configuration or channel estimation results. Different communication frequency bands correspond to different STF frame structures. For example, in the Option 1 band, an STF frame may contain 9 short training symbols, with a total number of sampling points of 9 × 16 = 144; in the Option 3 band, an STF frame may contain 10 short training symbols, with a total number of sampling points of 10 × 16 = 160. The signal receiving device sets the length of the buffer window based on the total number of sampling points in the STF frame of the current communication frequency band, making the buffer window length positively correlated with the total number of sampling points. In other words, the larger the total number of sampling points, the longer the buffer window length.

[0079] For example, taking the Option3 band as an example, its STF frame has 10 S symbols, corresponding to a total of 160 sampling points. Therefore, the buffer window length configured for this communication band is also set to 160, in order to slide and save the most recent 160 cross-correlation results. It is easy to understand that if 10 frequency offset compensation signals are currently used, then an independent buffer window is configured for each signal, for a total of 10 buffer windows.

[0080] In some implementations, the signal receiving device sets the buffer window length to be equal to the total number of sampling points in the STF frame (e.g., 160), so that the buffer window can store exactly the cross-correlation results within the number of sampling points in a complete STF frame from the current moment.

[0081] In other implementations, the signal receiving device sets the buffer window length to a fixed ratio with the total number of sampling points of the STF frame, for example, it can be 1.5 times or 0.5 times, and maintains a positive correlation.

[0082] In the above embodiments, by making the length of the buffer window positively correlated with the number of STF frame sampling points under the current communication frequency band, the length of the buffer window increases as the number of sampling points increases, so that the buffer window can cover a sufficiently long signal segment, and the set of cross-correlation results within the window is sufficient to reflect the complete periodic information of the STF frame, thereby making the calculated relative threshold more accurate and reliable.

[0083] In actual communication using dual-mode communication chips, due to frequency errors in the local oscillators of the signal transmitting and receiving devices and the channel Doppler effect, the received signal will have an unknown frequency offset. If only a single frequency offset compensation value is used, it is difficult to cover the entire frequency offset range allowed by the protocol, resulting in insufficient or excessive compensation, which in turn affects the peak significance of subsequent related calculations.

[0084] Based on this, in some embodiments, frequency offset pre-compensation is performed on the received signal to obtain multiple frequency offset compensation signals. Specifically, this includes: dividing the frequency offset range into several frequency offset assumption intervals based on the maximum allowable residual frequency offset range, with each frequency offset assumption interval corresponding to a frequency offset assumption; and performing frequency offset pre-compensation on the received signal according to each frequency offset assumption interval to obtain multiple frequency offset compensation signals.

[0085] The maximum residual frequency offset range refers to the maximum frequency deviation range that the received signal may exhibit relative to the transmitted signal, as allowed by the communication protocol. For example, the maximum residual frequency offset range could be ±25kHz. In feasible implementations, the maximum residual frequency offset range can be determined by one or more factors such as crystal oscillator accuracy and temperature drift.

[0086] The maximum residual frequency offset range is divided into several continuous sub-intervals, each covering a certain frequency offset width. The resulting sub-intervals are called frequency offset assumption intervals. A specific frequency offset value is set for each frequency offset assumption interval, which is called the frequency offset assumption. In some implementations, the frequency offset assumption can be, for example, the center frequency of the frequency offset assumption interval.

[0087] For example, assuming that the maximum residual frequency offset range allowed by the current communication protocol is [-K, K], and this maximum residual frequency offset range is divided into N frequency offset assumption intervals, then the frequency offset assumption value corresponding to each frequency offset assumption interval can be, for example, 2K / N.

[0088] For each defined frequency offset assumption interval, the signal receiving device performs pre-compensation processing on the received signal to obtain multiple frequency offset compensated signals.

[0089] For example, frequency offset compensation may involve applying reverse phase rotation or frequency shift processing to the received signal based on the frequency offset assumption values ​​corresponding to each frequency offset assumption interval.

[0090] Building upon this, in multi-path frequency offset compensation, if the frequency offset assumption interval is divided too finely and the number of paths is too large, although it can more precisely cover the frequency offset range, it will exponentially increase the computational load of subsequent cross-correlation, autocorrelation, and buffer processing, leading to increased chip power consumption and synchronization delay. This is particularly problematic in resource-constrained dual-mode communication chips, potentially impacting overall performance. Conversely, if the number of paths is too small, it may not effectively cover the maximum residual frequency offset range allowed by the protocol, resulting in insufficient frequency offset compensation. Therefore, a reasonable balance needs to be struck between coverage range and computational overhead.

[0091] Therefore, in some embodiments, the number of multiple frequency offset compensation signals is less than or equal to 10.

[0092] The signal receiving device sets the number of frequency offset assumption intervals to a positive integer not exceeding 10, based on the maximum residual frequency offset range specified in the communication protocol (e.g., ±25kHz) and the chip's processing capability. Specifically, the number of channels N satisfies 2 ≤ N ≤ 10. For example, when N=5, the divided frequency offset assumption intervals are [-25kHz, -15kHz], [-15kHz, -5kHz], [-5kHz, +5kHz], [+5kHz, +15kHz], and [+15kHz, +25kHz], with corresponding frequency offset assumption values ​​(taking the center of the interval) of -20kHz, -10kHz, 0kHz, +10kHz, and +20kHz. The receiving device performs pre-compensation in parallel according to these N frequency offset assumptions, obtaining N frequency offset compensation signals, with the number N less than or equal to 10. For chips with more limited resources, N=3 or N=4 can also be selected to further reduce the computational load.

[0093] In the above embodiments, by dividing the maximum residual frequency offset range into multiple frequency offset assumption intervals and pre-compensating them separately, it is possible to cover all possible frequency offset values ​​allowed by the communication protocol as much as possible, avoiding synchronization failure caused by a single compensation failing to cover the actual frequency offset. Simultaneously, the use of a multi-path parallel compensation structure allows subsequent cross-correlation and autocorrelation operations to be performed independently under multiple frequency offset assumptions, significantly improving robustness to unknown frequency offsets. Limiting the number of multi-path frequency offset compensation signals to less than 10 effectively controls the computational complexity and storage overhead of the dual-mode communication chip's parallel processing, achieving an optimized balance between synchronization accuracy and computational efficiency.

[0094] In practical signal synchronization, the relative threshold needs to reflect both the current signal energy level and the differences in STF frame structure across different frequency bands. Simply setting it may not be suitable for various communication frequency bands, leading to inconsistent decision-making effects of the relative threshold across different frequency bands.

[0095] Based on this, in some embodiments, a relative threshold for constraining the determination of autocorrelation peaks under the current signal environment is determined based on the cross-correlation results in each buffer window. Specifically, this includes: determining a threshold coefficient based on the communication frequency band of the received signal, and determining a cross-correlation reference value based on the cross-correlation results in each buffer window; and determining a relative threshold based on the threshold coefficient and the cross-correlation reference value.

[0096] The threshold coefficient is a numerical parameter related to the current communication frequency band of the signal, used to adjust the magnitude of the relative threshold. In some implementations, the threshold coefficient is usually determined based on the number of short training symbols in the current communication, for example, it can be equal to the number of short training symbols minus one, then divided by two, or it can be proportional to the number of short training symbols.

[0097] The cross-correlation baseline value is a statistical feature value extracted from the cross-correlation results of each buffer window, used to characterize the strength level of cross-correlation under the current signal environment.

[0098] The signal receiving device first determines the corresponding threshold coefficient based on the communication frequency band of the currently received signal. Then, it determines a cross-correlation reference value from the cross-correlation results stored in each buffer window. After this, the device calculates the threshold coefficient and the cross-correlation reference value to obtain the relative threshold for that channel or the entire signal. Through this process, the signal receiving device obtains a relative threshold that is correlated with the frequency band characteristics and the real-time signal strength.

[0099] In the above embodiments, by converting the relative threshold into two parts—a frequency-band-related threshold coefficient and a cross-correlation reference value—decoupling and integration of multiple influencing factors are achieved. On the one hand, the threshold coefficient ensures the rationality of the decision threshold under communication frequency bands with different numbers of short training symbols; on the other hand, the cross-correlation reference value allows the relative threshold to follow changes in signal amplitude and matching degree in real time, without the need for manual parameter tuning. The relative threshold generated by combining the two reflects both the structural characteristics at the protocol level and the real-time state at the channel level, thus providing accurate decision boundaries under different communication frequency bands and different signal-to-noise ratios, effectively filtering out false peaks at asynchronous positions, and improving the robustness and adaptability of synchronization.

[0100] In actual synchronization, the selection of the cross-correlation reference value directly affects the sensitivity and stability of the relative threshold. If the cross-correlation reference value only reflects the instantaneous cross-correlation state of the current sampling point, it may generate a large variance due to noise fluctuations, resulting in relative threshold jitter. If the cross-correlation reference value is taken from the global maximum value within a longer time window, the relative threshold will be more stable, but the response to signal changes may be slightly slower.

[0101] Based on this, in some embodiments, the cross-correlation benchmark value is the maximum value of the cross-correlation results within each cache window; or, the cross-correlation benchmark value is the maximum value of the cross-correlation results of the current sampling point within each cache window.

[0102] The maximum value among all cross-correlation results in each buffer window refers to the maximum value among all currently stored cross-correlation results in each buffer window after the signal receiving device has traversed all the buffer windows of the frequency offset compensation signal, and the cross-correlation reference value is taken as the cross-correlation reference value. The maximum value among the cross-correlation results of the current sampling point in each buffer window refers to the maximum value among the cross-correlation values ​​corresponding to the sampling point in all buffer windows at the same sampling point time, which is taken as the cross-correlation reference value.

[0103] It is easy to understand that, under normal circumstances, the maximum value among all cross-correlation results within each buffer window reflects the best performance of the matching degree with the local reference sequence within the most recent signal window; while the maximum value among the cross-correlation results of the current sampling point within each buffer window can reflect the best matching result among each frequency offset hypothesis in the current state.

[0104] In some implementations, the signal receiving device traverses all buffer windows, judges all cross-correlation results stored in each window, finds the maximum value, and then compares the maximum values ​​of each window, taking the largest one as the cross-correlation reference value. For example, if there are 10 buffer windows, and each buffer window stores 160 cross-correlation results, the signal receiving device finds the maximum value among these 1600 values, which is the cross-correlation reference value.

[0105] In other implementations, the signal receiving device acquires the latest cross-correlation result (i.e., the cross-correlation value corresponding to the current sampling point) stored in each buffer window at each sampling point, then compares these values ​​and takes the maximum value as the cross-correlation reference value. This reference value is updated synchronously with each sampling point, thereby reflecting in real time the best matching degree of each frequency offset assumption under the current signal environment.

[0106] In the above embodiments, a flexible trade-off between stability and response speed is achieved by using two different methods to determine the cross-correlation reference value. When using the global maximum value method of the buffer window, the cross-correlation reference value is based on the best cross-correlation result over a longer period of time, is less affected by instantaneous noise, and has a relatively smooth threshold fluctuation. When using the maximum value method of the current sampling point, the cross-correlation reference value follows the best match of each sampling point in real time, has a rapid relative threshold response, and can capture changes in the signal environment more quickly.

[0107] It should be noted that in actual signal synchronization of dual-mode communication, the determination methods of the two cross-correlation reference values ​​can be selected or switched according to the processing delay, storage resources, and channel characteristics of the chip or system, thereby further improving the adaptability and flexibility of the signal synchronization method.

[0108] The threshold coefficient is a crucial parameter affecting the relative threshold size. If a fixed value is used, it becomes difficult to adapt to varying numbers of short training symbols across different communication frequency bands, leading to inconsistent decision criteria for the relative threshold under different configurations. For example, frequency bands with a larger number of short training symbols have more autocorrelation accumulation terms and higher autocorrelation peak amplitudes; therefore, a correspondingly larger threshold coefficient is needed to effectively constrain false peaks in the relative threshold.

[0109] Based on this, in some embodiments, the threshold coefficient is positively correlated with the number of repeating sequences in the STF frame of the received signal.

[0110] The number of repeated sequences in an STF frame refers to the number of short training symbols within the STF frame. These symbols typically have a repetitive structure, and the number of repeated sequences determines the number of adjacent cross-correlation values ​​that participate in the accumulation during autocorrelation calculation.

[0111] The signal receiving device first determines the number N of repeating sequences (i.e., short training symbols) in the STF frame under the current communication frequency band. For example, let N=9 under Option 1 band and N=10 under Option 3 band, and then set the threshold coefficient. It is positively correlated with N.

[0112] In some implementations... When N=9, =4; when N=10 =4.5.

[0113] In other implementations, a linear relationship may also be used, making That is, set This is a scaling factor that makes the threshold coefficient increase as the number of repeating sequences increases, and decrease as the number of repeating sequences decreases.

[0114] In the above embodiments, by making the threshold coefficient positively correlated with the number of repeating sequences in the STF frame, adaptive matching of the relative threshold to frame structure differences is achieved. Specifically, the more repeating sequences there are, the more terms are accumulated during autocorrelation calculation (the number of times adjacent cross-correlation values ​​are multiplied and accumulated), and the larger the amplitude of the autocorrelation peak under ideal synchronization. If the threshold coefficient does not increase with N, the relative threshold may be too small relative to the autocorrelation peak, making it easier for false peaks to exceed the threshold in high N frequency bands. By setting a positive correlation, the threshold coefficient can rise synchronously with the increase of the number of accumulated terms, so that the relative threshold is kept at an energy level that can effectively constrain the autocorrelation peak. This ensures that synchronization decisions under different frequency bands have consistent false alarm performance, avoids the problem of needing to recalibrate the threshold coefficient due to frequency band switching, and improves the versatility and robustness of the dual-mode communication chip in multi-mode configurations.

[0115] When determining the relative threshold, relying solely on the linear relationship between the threshold coefficient and the cross-correlation baseline may not accurately reflect the energy accumulation characteristics of the autocorrelation results.

[0116] Therefore, in some embodiments, the relative threshold is the product of the threshold coefficient and the square of the cross-correlation baseline value.

[0117] After acquiring the threshold coefficient and the cross-correlation reference value, the signal receiving device calculates the relative threshold based on both. Specifically, let the threshold coefficient be... The cross-correlation baseline value is Then relative threshold The calculation is as follows: .

[0118] For example, taking Option 3 as an example, the threshold coefficient is equal to the number of short training symbols, 10 minus 1, divided by 2. Let the cross-correlation baseline value be... relative threshold Through the above calculations, the signal receiving device can obtain a relative threshold that is proportional to the square of the cross-correlation reference value.

[0119] Figure 4 This is a schematic diagram of the polarity arrangement and synchronization status of short training symbols in the Option3 communication band provided in some embodiments of the present invention. For example... Figure 4 As shown, taking the Option3 band as an example, the STF frame contains 10 short training symbols, labeled a1 to a10 respectively, and each symbol corresponds to a sampling point position (i.e., the output position of the cross-correlation result). Figure 4 The polarity of each short training symbol is shown: a1 is S, a2 is -S, a3 is -S, a4 is -S, a5 is S, a6 is S, a7 is -S, a8 is -S, a9 is -S, and a10 is -S. Furthermore, Figure 4 In this context, t0 represents the starting position of the STF frame, and t1 represents the position where the current sampling point is perfectly aligned. Under ideal synchronization, the cross-correlation value a1 at time t1 reaches its maximum value, and the cross-correlation values ​​a2 to a10 for subsequent symbols are approximately equal to a1. At this point, autocorrelation is calculated on the cross-correlation values ​​between adjacent symbols (i.e.,...). The result is approximately equal to .

[0120] Therefore, the reason for squaring the cross-correlation benchmark value is that, under ideal synchronization, the result of autocorrelation calculation (multiplying adjacent terms and then summing) of multiple consecutive cross-correlation results is approximately equal to (number of short training symbols - 1) multiplied by the square of the cross-correlation benchmark value. The energy level of the autocorrelation result is proportional to the square of the cross-correlation benchmark value. If the relative threshold is set to have a linear relationship with the cross-correlation benchmark value, it is difficult to accurately match the actual amplitude of the autocorrelation result. This results in the relative threshold being relatively low when the signal is strong (insufficient to filter out false peaks) or relatively high when the signal is weak (potentially missing true peaks). By using the square operation, the relative threshold can correspond to the energy characteristics of the autocorrelation result, thereby more accurately determining whether the autocorrelation peak has reached the energy level that true synchronization should have, significantly improving the ability to distinguish between true and false peaks.

[0121] In the above embodiments, by setting the relative threshold as the product of the threshold coefficient and the square of the cross-correlation benchmark value, the relative threshold can be directly correlated with the order of magnitude of the cross-correlation result, thereby more accurately determining whether the autocorrelation peak has reached the energy level that true synchronization should have, thus significantly enhancing the relative threshold's ability to distinguish between true and false peaks.

[0122] After initially identifying candidate synchronization locations, multiple candidate peaks may exist due to multipath effects or noise interference. Relying solely on a single peak comparison may lead to the identification of a non-true synchronization location. For example, a slightly smaller false peak may exist near the true synchronization peak. Directly determining the first candidate location that meets the criteria as the synchronization point may miss larger true peaks later on. Therefore, it is necessary to continue monitoring within a preset range after the candidate location.

[0123] Based on this, in some embodiments, the synchronization position of the received signal is determined based on the signal position corresponding to the frequency offset compensation signal that generates the maximum autocorrelation result. Specifically, this includes: when the maximum autocorrelation value is greater than a preset autocorrelation threshold and greater than a relative threshold, determining the signal position corresponding to the frequency offset compensation signal that generates the maximum autocorrelation result as a candidate synchronization position; continuing to detect autocorrelation results within a preset synchronization range after the candidate synchronization position; if no autocorrelation result greater than the maximum autocorrelation value is detected, determining the candidate synchronization position as the synchronization position of the received signal; if an autocorrelation result greater than the maximum autocorrelation value is detected, updating the candidate synchronization position based on the signal position corresponding to the subsequent autocorrelation result, and determining the synchronization position of the received signal based on the updated candidate synchronization position.

[0124] The candidate synchronization position refers to the signal position corresponding to the maximum autocorrelation value when it first simultaneously exceeds both the preset autocorrelation threshold and the relative threshold. The signal receiving device considers it a potential synchronization point, but does not directly use it as the signal synchronization point.

[0125] The preset synchronization range refers to a pre-defined time length used to continue searching for a larger autocorrelation result within a certain interval after the candidate synchronization position. For example, the preset synchronization range can be the number of sampling points corresponding to 1.5 short training symbols, or it can be the number of sampling points corresponding to 1 short training symbol.

[0126] Updating candidate synchronization position refers to the process of replacing the original candidate position with the signal position corresponding to the larger autocorrelation result when the signal receiving device detects a larger autocorrelation result within a preset synchronization range, and continuing to monitor after the new position until the synchronization range ends.

[0127] When the maximum autocorrelation value of a signal receiving device is simultaneously greater than both a preset autocorrelation threshold and a relative threshold, it first records the signal position corresponding to the maximum value as a candidate synchronization position. Then, within a preset synchronization range following the candidate synchronization position, it continues to calculate the autocorrelation result for subsequent sampling points. If an autocorrelation result greater than the currently recorded maximum value is detected at a position within the preset synchronization range, that position is updated as a new candidate synchronization position, and the larger autocorrelation value is used as the new comparison benchmark. Monitoring then continues from the new candidate synchronization position until the entire preset synchronization range has been traversed. Finally, the candidate synchronization position updated in the last update is taken as the synchronization position of the received signal.

[0128] In the above embodiments, by setting a preset synchronization range after the candidate synchronization position and continuing detection, false synchronization caused by prematurely locking the synchronization point due to the first appearance of a peak value that meets the conditions is avoided. Continuous comparison within the preset range ensures that the finally selected synchronization position is the maximum value point of the autocorrelation result within the cache window, thereby significantly improving the accuracy of synchronization position determination. At the same time, by dynamically updating the candidate synchronization positions, stronger signal peaks can be adaptively determined without restarting the entire synchronization process, balancing detection accuracy and computational efficiency.

[0129] The HRF signal synchronization method in a dual-mode communication chip provided in this embodiment of the invention can be executed by an HRF signal synchronization device in a dual-mode communication chip. This embodiment of the invention uses an HRF signal synchronization device in a dual-mode communication chip executing the HRF signal synchronization method as an example to illustrate the HRF signal synchronization device in a dual-mode communication chip provided in this embodiment of the invention.

[0130] Figure 5 This is a schematic diagram of the HRF signal synchronization device structure in a dual-mode communication chip provided in some embodiments of the present invention. For example... Figure 5 As shown, the HRF signal synchronization device in the dual-mode communication chip includes: a compensation module 501, a buffer module 502, a determination module 503, an autocorrelation module 504, and a synchronization module 505.

[0131] The compensation module 501 is used to perform frequency offset pre-compensation on the received signal to obtain multiple frequency offset compensation signals; The cache module 502 is used to perform cross-correlation calculations on each frequency offset compensation signal to obtain the cross-correlation results corresponding to each compensation signal, and cache the cross-correlation results corresponding to each compensation signal into their respective cache windows. The determination module 503 is used to determine the relative threshold for constraining the autocorrelation peak determination under the current signal environment based on the cross-correlation results in each buffer window; the relative threshold changes dynamically with the change of the cross-correlation results. The autocorrelation module 504 is used to perform autocorrelation calculations on the cross-correlation results corresponding to each compensation signal, obtain the autocorrelation results corresponding to each compensation signal, and determine the maximum value of the autocorrelation results corresponding to each compensation signal. The synchronization module 505 is used to determine the synchronization position of the received signal based on the signal position in the frequency offset compensation signal that generates the maximum value of the autocorrelation result when the maximum value of the autocorrelation result is greater than a preset autocorrelation threshold and greater than a relative threshold.

[0132] The HRF signal synchronization device in the dual-mode communication chip provided by the present invention performs cross-correlation calculation on multiple frequency offset compensation signals obtained by frequency offset pre-compensation of the received signal to obtain the cross-correlation results corresponding to each compensation signal. This enhances the matching response between the signal and the local sequence within a certain frequency offset range, thereby enabling the cross-correlation results to form a significant peak at the true synchronization position, thus achieving enhanced extraction of effective signal components in the received signal. Subsequently, the cross-correlation results corresponding to each compensation signal are cached into their respective cache windows. Based on the cross-correlation results in each cache window, a relative threshold for constraining autocorrelation peak determination under the current signal environment can be determined. This allows the cross-correlation results within the cache window to be dynamically updated, thereby determining a cross-correlation benchmark value that changes with the real-time signal based on the cross-correlation results in the current window, and generating a relative threshold accordingly. This achieves dynamic correlation between synchronization decision and the current signal. Since the relative threshold changes synchronously with the update of the cache window, it always reflects the best matching degree within the most recent signal window. This approach effectively avoids the risk of misjudging synchronization peaks due to abnormally increased cross-correlation values ​​at asynchronous positions caused by multi-path pre-compensation, thus significantly improving the accuracy of synchronization position determination. Subsequently, autocorrelation calculations are performed on the cross-correlation results corresponding to each compensation signal. Based on the obtained autocorrelation results for each compensation signal, the maximum value of the autocorrelation result is determined. This allows for the superposition of effective signal energy while suppressing random noise, resulting in a significantly higher autocorrelation result for the true synchronization position compared to the asynchronous position, achieving separation of correlation peaks from noise. Finally, when the maximum value of the autocorrelation result is greater than a preset autocorrelation threshold and a relative threshold, the synchronization position of the received signal is determined based on the signal position corresponding to the frequency offset compensation signal that generates the maximum autocorrelation result. The preset autocorrelation threshold can be used to remove low-energy noise, and a dynamic relative threshold can be used to filter out false peaks at asynchronous positions under high signal-to-noise ratio (SNR) conditions. This improves the success rate of low SNR detection while significantly reducing the probability of false synchronization in high SNR environments, achieving high-precision wireless signal synchronization.

[0133] In some embodiments, the determining module is further configured to determine a threshold coefficient based on the communication frequency band of the received signal, and determine a cross-correlation reference value based on the cross-correlation results in each buffer window; and determine a relative threshold based on the threshold coefficient and the cross-correlation reference value.

[0134] In some embodiments, the synchronization module is further configured to: when the maximum autocorrelation value is greater than a preset autocorrelation threshold and greater than a relative threshold, determine the signal position corresponding to the frequency offset compensation signal that generates the maximum autocorrelation result as a candidate synchronization position; continue to detect autocorrelation results within a preset synchronization range after the candidate synchronization position; if no autocorrelation result greater than the maximum autocorrelation value is detected, determine the candidate synchronization position as the synchronization position of the received signal; if an autocorrelation result greater than the maximum autocorrelation value is detected, update the candidate synchronization position based on the signal position corresponding to the subsequent autocorrelation result, and determine the synchronization position of the received signal based on the updated candidate synchronization position.

[0135] In some embodiments, the compensation module is further configured to divide the frequency offset range into several frequency offset assumption intervals based on the maximum allowable residual frequency offset range, with each frequency offset assumption interval corresponding to a frequency offset assumption; and to perform frequency offset pre-compensation on the received signal according to each frequency offset assumption interval to obtain multiple frequency offset compensation signals.

[0136] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0137] In this embodiment of the invention, the HRF signal synchronization device in the dual-mode communication chip can be an electronic device or a component within an electronic device, such as an integrated circuit or a chip. This electronic device can be a terminal or other devices besides a terminal, such as a server.

[0138] The HRF signal synchronization device in the dual-mode communication chip provided in this embodiment of the invention can realize all the processes implemented in the above-described embodiment of the HRF signal synchronization method in the dual-mode communication chip. To avoid repetition, these processes will not be described again here.

[0139] In some embodiments, Figure 6These are schematic diagrams of the electronic device provided in some embodiments of the present invention. For example... Figure 6 As shown, this embodiment of the invention also provides an electronic device 600, including a processor 601, a memory 602, and a computer program stored in the memory 602 and executable on the processor 601. When the program is executed by the processor 601, it implements the various processes of the HRF signal synchronization method embodiment in the dual-mode communication chip described above, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0140] This invention provides a non-transitory computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the various processes of the HRF signal synchronization method embodiment in the dual-mode communication chip described above, and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0141] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable media, such as computer read-only memory (ROM), random-access memory (RAM), magnetic disks, or optical disks.

[0142] The computer-readable storage medium may include: read-only memory (ROM), random-access memory (RAM), magnetic disk or optical disk, etc.

[0143] This invention provides a computer program product, including a computer program that, when executed by a processor, implements the HRF signal synchronization method in the dual-mode communication chip described above.

[0144] This invention provides a chip that includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the HRF signal synchronization method embodiment in the dual-mode communication chip described above, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0145] It should be understood that the chip mentioned in the embodiments of the present invention may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0146] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0147] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the related technology, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0148] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

[0149] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0150] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for synchronizing HRF signals in a dual-mode communication chip, characterized in that, include: Frequency offset pre-compensation is performed on the received signal to obtain multiple frequency offset compensated signals; Cross-correlation calculations are performed on each frequency offset compensation signal to obtain the cross-correlation results for each compensation signal, and the cross-correlation results for each compensation signal are cached in their respective cache windows. Based on the cross-correlation results in each buffer window, a relative threshold for constraining the autocorrelation peak determination is determined under the current signal environment; the relative threshold changes dynamically with the change of the cross-correlation results. Autocorrelation calculations are performed on the cross-correlation results corresponding to each compensation signal to obtain the autocorrelation results corresponding to each compensation signal, and the maximum value of the autocorrelation results corresponding to each compensation signal is determined. If the maximum value of the autocorrelation result is greater than a preset autocorrelation threshold and greater than the relative threshold, the synchronization position of the received signal is determined based on the signal position corresponding to the frequency offset compensation signal that generates the maximum value of the autocorrelation result.

2. The HRF signal synchronization method in a dual-mode communication chip according to claim 1, characterized in that, The determination of the relative threshold for constraining autocorrelation peak determination under the current signal environment based on the cross-correlation results in each buffer window includes: The threshold coefficient is determined based on the communication frequency band of the received signal, and the cross-correlation reference value is determined based on the cross-correlation results in each buffer window. The relative threshold is determined based on the threshold coefficient and the cross-correlation benchmark value.

3. The HRF signal synchronization method in a dual-mode communication chip according to claim 2, characterized in that, The relative threshold is the product of the threshold coefficient and the square of the cross-correlation benchmark value.

4. The HRF signal synchronization method in a dual-mode communication chip according to claim 2, characterized in that, The cross-correlation benchmark value is the maximum value among the cross-correlation results in each cache window; or, the cross-correlation benchmark value is the maximum value among the cross-correlation results of the current sampling point in each cache window.

5. The HRF signal synchronization method in a dual-mode communication chip according to claim 2, characterized in that, The threshold coefficient is positively correlated with the number of repeating sequences in the STF frame of the received signal.

6. The HRF signal synchronization method in a dual-mode communication chip according to any one of claims 1 to 5, characterized in that, Determining the synchronization position of the received signal based on the signal position corresponding to the frequency offset compensation signal that generates the maximum value of the autocorrelation result includes: When the maximum value of the autocorrelation is greater than the preset autocorrelation threshold and greater than the relative threshold, the signal position corresponding to the frequency offset compensation signal that generates the maximum value of the autocorrelation result is determined as the candidate synchronization position. Within a preset synchronization range after the candidate synchronization position, the autocorrelation result is continued to be detected; if no autocorrelation result greater than the maximum value of the autocorrelation is detected, the candidate synchronization position is determined as the synchronization position of the received signal; If an autocorrelation result greater than the maximum value of the autocorrelation is detected, the candidate synchronization position is updated based on the signal position corresponding to the subsequent autocorrelation result, and the synchronization position of the received signal is determined according to the updated candidate synchronization position.

7. The HRF signal synchronization method in a dual-mode communication chip according to claim 1, characterized in that, The step of performing frequency offset pre-compensation on the received signal to obtain multiple frequency offset compensated signals includes: Based on the maximum allowable residual frequency offset range, the frequency offset range is divided into several frequency offset hypothesis intervals, and each frequency offset hypothesis interval corresponds to a frequency offset hypothesis. The received signal is pre-compensated for frequency offset according to each frequency offset assumption interval to obtain multiple frequency offset compensated signals.

8. The HRF signal synchronization method in a dual-mode communication chip according to claim 1, characterized in that, The relative threshold is greater than the preset autocorrelation threshold, and the degree of difference is related to the signal-to-noise ratio of the current signal environment.

9. The HRF signal synchronization method in a dual-mode communication chip according to claim 1, characterized in that, The length of the buffer window is associated with the communication frequency band of the received signal and is positively correlated with the number of sampling points in the STF frame.

10. The HRF signal synchronization method in a dual-mode communication chip according to claim 1, characterized in that, The number of the multi-channel frequency offset compensation signals is less than or equal to 10.

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