Method and device for wireless signal synchronization in power line carrier multi-mode communication system

Abstract

The application discloses a wireless signal synchronization method and device in a power line carrier multi-mode communication system, and belongs to the technical field of power line carrier communication. The wireless signal synchronization method in the power line carrier multi-mode communication system comprises the following steps: sampling a frequency shift keying time domain signal received to obtain a sample point sequence; determining phase differences corresponding to each sample point in the sample point sequence respectively, performing signed aggregation on the phase differences in the same cycle phase to form a cycle phase accumulation sequence; summing absolute values of two phase accumulation values separated by a preset number in the cycle phase accumulation sequence to obtain a peak intensity sequence, and performing signed average on each phase accumulation value to obtain a waveform balance value; and determining a synchronization position of a frequency shift keying preamble according to a cycle phase corresponding to a maximum value of the peak intensity sequence in the case that the maximum value is greater than a first threshold value and an absolute value of the waveform balance value is less than a second threshold value. The application realizes high-precision signal synchronization.

Description

Technical Field

[0001] This invention belongs to the field of power line carrier communication technology, and particularly relates to a method and apparatus for wireless signal synchronization in a power line carrier multimode communication system. Background Technology

[0002] With the development of power Internet of Things (IoT) technology, various services have placed higher demands on the coverage, transmission reliability, and scenario adaptability of communication systems. Single communication methods are no longer sufficient to meet the needs of practical applications. Therefore, multi-mode communication technology has emerged, which can simultaneously support multiple communication methods such as power line carrier communication, domestic wireless communication, and international wireless communication to adapt to different communication scenarios.

[0003] In wireless communication, the receiving end typically needs to synchronize the received signal to determine its starting position. In related technologies, the receiving end usually detects the received signal based on the repetitive characteristics of the preamble sequence, thereby determining whether the target signal has been received and further determining the location for subsequent demodulation of the data in the signal.

[0004] However, in multi-mode communication scenarios, different communication signals may operate simultaneously in the same or adjacent frequency bands. Since the preamble portions of different signals may have certain repetitive characteristics, relying solely on the repetition of the preamble sequence for synchronization detection can easily lead to misidentification of other communication signals as the target signal. Furthermore, factors such as noise, frequency offset, and adjacent channel interference may make the repetitive characteristics of the preamble sequence in the received signal less obvious, making it difficult for the receiver to accurately detect the target signal during synchronization, thereby affecting the accuracy of subsequent data demodulation and communication reliability. 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 a method and apparatus for wireless signal synchronization in a power line carrier multimode communication system to achieve high-precision signal synchronization.

[0006] In a first aspect, the present invention provides a method for wireless signal synchronization in a power line carrier multimode communication system, the method comprising: The received frequency shift keying time domain signal is sampled to obtain a sampling point sequence. Each symbol of the frequency shift keying time domain signal corresponds to a preset number of sampling points. The phase difference corresponding to each sampling point in the sampling point sequence is determined, and the phase differences in the same period phase are signedly aggregated according to the repetition period of the frequency shift keying preamble to form a periodic phase accumulation sequence. Two phase accumulation values ​​separated by a preset number in the periodic phase accumulation sequence are grouped together. The absolute values ​​of the two phase accumulation values ​​in each group are summed to obtain the peak intensity sequence. The signed average of each phase accumulation value in the periodic phase accumulation sequence is then performed to obtain the waveform balance value. When the maximum value of the peak intensity sequence is greater than the first threshold and the absolute value of the waveform balance value is less than the second threshold, the synchronization position of the frequency shift keying preamble is determined according to the periodic phase corresponding to the maximum value.

[0007] According to one embodiment of the present invention, the frequency shift keying preamble includes two alternating preamble symbols, with each repetition period corresponding to two preamble symbols. The phase differences of samples in the same period phase are signedly aggregated according to the repetition period of the frequency shift keying preamble to form a periodic phase accumulation sequence. Specifically, this includes: determining twice the preset number of period phases based on the repetition period; for any period phase, accumulating the phase differences of each sampling point in the sampling point sequence that is in the corresponding period phase and has an interval twice the preset number between adjacent sampling points to obtain the phase accumulation value corresponding to the corresponding period phase; and combining the corresponding phase accumulation values ​​according to the order of arrangement of each period phase within the repetition period to obtain the periodic phase accumulation sequence.

[0008] According to one embodiment of the present invention, the second threshold is less than the first threshold; the preset number is 16, and the frequency shift keying preamble includes preamble symbols arranged alternately with 0 and 1.

[0009] According to one embodiment of the present invention, the phase difference corresponding to each sampling point in the sampling point sequence is determined respectively, specifically including: for any sampling point, determining a reference sampling point that is separated from the corresponding sampling point by a phase measurement interval from the sampling point sequence; performing conjugate multiplication on the complex sampling value of the corresponding sampling point and the complex sampling value of the reference sampling point, and determining the phase difference corresponding to the corresponding sampling point based on the conjugate multiplication result.

[0010] According to one embodiment of the present invention, the phase measurement interval is the ratio of a preset number to a scaling factor, wherein the scaling factor is determined based on the modulation index of the frequency shift keying time domain signal.

[0011] According to one embodiment of the present invention, determining the synchronization position of the frequency shift keying preamble based on the periodic phase corresponding to the maximum value specifically includes: determining a set of phase accumulation values ​​corresponding to the maximum value; determining the positive peak phase or negative peak phase of the frequency shift keying preamble based on the periodic phase corresponding to the corresponding set of phase accumulation values; and determining the sampling position corresponding to the positive peak phase or negative peak phase as the synchronization position.

[0012] According to one embodiment of the present invention, the method further includes: determining a plurality of symbol decision sampling points sequentially from the sampling point sequence based on the synchronization position; determining the symbol decision result corresponding to each symbol decision sampling point according to the positive or negative sign of the phase difference corresponding to each symbol decision sampling point; and obtaining a symbol decision sequence according to the symbol decision result corresponding to the timing combination of each symbol decision sampling point.

[0013] According to one embodiment of the present invention, the symbol decision result corresponding to each symbol decision sampling point is determined based on the positive or negative sign of the phase difference corresponding to each symbol decision sampling point. Specifically, this includes: selecting a plurality of decision reference points with an odd total number from the sampling point sequence, centered on any symbol decision sampling point; counting the number of positive phase differences and negative phase differences among the phase differences corresponding to the plurality of decision reference points; when the number of positive phase differences is greater than the number of negative phase differences, determining the symbol decision result corresponding to the corresponding symbol decision sampling point as a first value; and when the number of negative phase differences is greater than the number of positive phase differences, determining the symbol decision result corresponding to the corresponding symbol decision sampling point as a second value.

[0014] According to an embodiment of the present invention, the method further includes: writing the sequentially obtained symbol decision results into a decision window, the length of which is the same as the sequence length of the local frame start delimiter sequence; updating the symbol decision sequence in the decision window for each new symbol decision result obtained, and matching the updated symbol decision sequence with the local frame start delimiter sequence; when the matching is successful, determining the symbol decision sampling point corresponding to the latest symbol decision result written into the decision window as the end position of the frame start delimiter, and determining the sampling position of the symbol after the end position as the start position of the physical layer header.

[0015] In a second aspect, the present invention provides a wireless signal receiving device for use in a power line carrier multimode communication system, the device comprising: Radio frequency receiving circuit, used to receive frequency shift keying time domain signals; The sampling circuit, connected to the RF receiving circuit, is used to sample the frequency shift keying time domain signal; The processor, connected to the sampling circuit, is used to execute the wireless signal synchronization method in the power line carrier multimode communication system described in the first aspect above.

[0016] 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 wireless signal synchronization method in the power line carrier multimode communication system as described in the first aspect above.

[0017] 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 wireless signal synchronization method in a power line carrier multimode communication system as described in the first aspect above.

[0018] Fifthly, the present invention provides a chip comprising 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 wireless signal synchronization method in the power line carrier multimode communication system as described in the first aspect.

[0019] In a sixth aspect, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the wireless signal synchronization method in a power line carrier multimode communication system as described in the first aspect above.

[0020] 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 sampling the received frequency shift keying (FSK) time-domain signal, a sampling point sequence is obtained, with each symbol of the FFS time-domain signal corresponding to a preset number of sampling points. This provides a unified and stable data foundation for subsequent phase difference calculation and aggregation by repetition period, avoiding the impact of inconsistent sampling scales on synchronization judgment. Based on this, by determining the phase difference corresponding to each sampling point in the sampling point sequence and performing signed aggregation of phase differences in the same period phase according to the repetition period of the FFS preamble, a periodic phase accumulation sequence is formed. This allows phase differences conforming to the preamble repetition pattern to accumulate and strengthen in the same period phase, while noise or interference that does not conform to this repetition pattern is difficult to accumulate stably, thereby improving the saliency of the preamble features and enhancing the anti-noise and anti-interference capabilities of signal synchronization detection. Furthermore, two phases separated by a preset number in the periodic phase accumulation sequence are accumulated... The values ​​are divided into groups, and the absolute values ​​of the two phase accumulation values ​​in each group are summed to obtain the peak intensity sequence. Then, the signed average of each phase accumulation value in the periodic phase accumulation sequence is performed to obtain the waveform balance value. This allows us to simultaneously obtain the local peak intensity and the overall positive and negative balance of the preamble, which not only improves the detection capability of the real preamble but also suppresses false detections caused by non-target signals with only local peaks or significant overall bias. Finally, when the maximum value of the peak intensity sequence is greater than the first threshold and the absolute value of the waveform balance value is less than the second threshold, the synchronization position of the frequency shift keying preamble is determined based on the periodic phase corresponding to the maximum value. The synchronization results can be jointly constrained by the local peak intensity and the overall balance, making the determination of the synchronization position more accurate and reliable, thereby reducing the probability of false synchronization and improving the accuracy of frequency shift keying signal synchronization detection and the reliability of subsequent data demodulation.

[0021] 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

[0022] 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 flowchart illustrating a wireless signal synchronization method in a power line carrier multimode communication system provided in some embodiments of the present invention; Figure 2 This is a schematic diagram illustrating the determination of the phase difference corresponding to the sampling point under different phase measurement intervals in some embodiments of the present invention; Figure 3 This is a schematic diagram illustrating the determination of the phase difference corresponding to the sampling point under different phase measurement intervals in other embodiments of the present invention; Figure 4 This is a schematic diagram of the structure of a wireless signal receiving device provided in some embodiments of the present invention; Figure 5 This is a schematic diagram of the structure of an electronic device provided in some embodiments of the present invention. Detailed Implementation

[0023] 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.

[0024] 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.

[0025] As the business scenarios of the power Internet of Things (IoT) continue to expand, the communication objects, communication environments, and business types in the power system are becoming increasingly complex. Power IoT communication not only needs to support services such as electricity consumption information collection, distribution automation, intelligent monitoring of distribution areas, load control, distributed energy access, and power quality monitoring, but also needs to adapt to different application scenarios such as low-voltage distribution areas, distribution rooms, substations, user-side terminals, and edge sensing devices. Different services have significantly different requirements for communication distance, transmission rate, coverage, real-time performance, power consumption, networking capabilities, and communication reliability. For example, some services prioritize long-distance coverage and low-power transmission, some prioritize high reliability and anti-interference capabilities, while others have high requirements for data transmission rate and latency. Therefore, a single communication mode is usually insufficient to simultaneously meet the communication needs of the diverse business scenarios of the power IoT.

[0026] To improve the adaptability of communication terminals to complex application environments, multi-mode communication technology is increasingly being applied to power IoT communication terminals. Multi-mode communication technology refers to a single communication terminal supporting two or more communication modes, and the ability to select the appropriate mode based on service requirements, channel conditions, network coverage, or interference environments. Typically, a power IoT communication terminal can simultaneously support wired communication based on power line communication (PLC), wireless communication based on domestic wireless communication protocols, and wireless communication based on foreign wireless communication protocols. By introducing a multi-mode communication mechanism, the communication terminal can achieve complementary communication links in different scenarios, improving network coverage, service carrying capacity, and communication reliability.

[0027] However, in a multi-mode communication environment, signals corresponding to different communication modes may coexist in the same terminal, the same spatial area, or adjacent communication frequency bands. Due to differences in modulation methods, spectrum occupancy, transmit power, bandwidth, and time slot planning among different communication systems, problems such as spectrum overlap, adjacent-channel interference, out-of-band leakage, or intermodulation interference can easily arise between various communication signals. For example, frequency-shift keying (FSK) signals typically represent different symbols using different carrier frequencies or frequency offsets, offering advantages such as simple implementation, low power consumption, and suitability for low-speed reliable communication. Orthogonal frequency division multiplexing (OFDM) signals, on the other hand, are typically composed of multiple mutually orthogonal subcarriers, exhibiting high spectrum utilization and strong multipath resistance. When FSK signals and OFDM signals overlap or are adjacent in the frequency domain, the subcarrier components, sidelobe leakage, or adjacent-channel energy of the OFDM signal may fall within the receiving bandwidth of the FSK signal, thus affecting the reception and detection of the FSK signal.

[0028] For the reception of frequency shift keying (FSK) signals, synchronization detection is a crucial step for subsequent demodulation and data recovery. The receiver typically needs to determine the start position, symbol boundary, or sampling decision time of the FFS signal based on the preamble, synchronization word, or a specific training sequence. If the synchronization position is accurately determined, the receiver can complete frequency decision and symbol demodulation within the correct time window; if the synchronization position is offset, it may lead to symbol boundary errors, inaccurate frequency decision, increased bit error rate, or even prevent the correct parsing of subsequent data frames. In the presence of OFDM signals, other wireless signals, PLC noise, impulse interference, or thermal noise, the periodic characteristics and correlation peaks of the FFS preamble may be weakened or masked, causing misjudgments, missed detections, or false alarms in the synchronization detection results.

[0029] Especially in power Internet of Things (IoT) applications, the environment in which communication terminals operate is complex. Both power line channels and wireless channels can be affected by load changes, switching operations, electromagnetic radiation, multipath propagation, fading due to obstruction, and communication activities of nearby devices. These factors can cause the received signal to simultaneously contain target frequency shift keying (FSK) signals, signals from other communication modes, and random noise. This makes it difficult for traditional synchronization methods based on energy detection, fixed threshold detection, or simple correlation detection to maintain stable performance under low signal-to-noise ratio (SNR) or strong interference conditions.

[0030] Therefore, in the multi-mode coexistence of power Internet of Things communication scenarios, how to accurately identify the preamble of the frequency shift keying signal and determine the synchronization position of the frequency shift keying signal in the presence of other signal interference has become a technical problem that urgently needs to be solved to ensure reliable reception of the frequency shift keying signal and correct demodulation of subsequent data.

[0031] In view of this, embodiments of the present invention provide a wireless signal synchronization method in a power line carrier multimode communication system, aiming to solve the problem that frequency shift keying signals are prone to misjudgment of synchronization position when interfered with in a multimode communication coexistence environment. By extracting the phase difference of the frequency shift keying signal and using the periodic repetition characteristic of the preamble of the frequency shift keying signal to perform signed aggregation of the phase differences in the same period phase, the preamble characteristics of the frequency shift keying signal are enhanced, so as to achieve high-precision signal synchronization.

[0032] The wireless signal synchronization method in a power line carrier multimode communication system provided in this invention is applied to a power line carrier communication system including a signal transmitting device and a signal receiving device. The signal transmitting device transmits a frequency shift keying (FSK) time-domain signal to the signal receiving device. The signal receiving device receives the FSK time-domain signal and processes the received FSK time-domain signal.

[0033] 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, wireless communication modules, dual-mode or multi-mode communication modules, communication test terminals, etc. Alternatively, the electronic devices can also be devices with signal processing capabilities to perform signal reception, sampling processing, signed aggregation, period accumulation, peak intensity sequence construction, waveform balance value construction, synchronization position determination, and subsequent demodulation processing as described in the embodiments of the present invention.

[0034] The following description uses a signal receiving device as an example to illustrate the wireless signal synchronization method in a power line carrier multimode communication system provided by the embodiments of the present invention.

[0035] Figure 1 This is a flowchart illustrating a wireless signal synchronization method in a power line carrier multimode communication system provided in some embodiments of the present invention. For example... Figure 1 As shown, the wireless signal synchronization method in the power line carrier multimode communication system includes steps 110 to 140.

[0036] Step 110: Sample the received frequency shift keying time domain signal to obtain a sampling point sequence. Each symbol of the frequency shift keying time domain signal corresponds to a preset number of sampling points.

[0037] Among them, frequency shift keying time domain signal refers to the time domain signal obtained by the wireless signal transmitting device using frequency shift keying modulation to modulate the data to be transmitted and the preamble, and then receiving it after radio frequency transmission.

[0038] Furthermore, each symbol of the frequency shift keying time-domain signal includes multiple sampling points, and each symbol has a corresponding frequency state within the corresponding symbol duration. Different frequency states are used to characterize different information values, so that the signal receiving device can perform phase difference extraction and synchronization detection based on multiple sampling points.

[0039] The signal receiving device first samples the received frequency-shift keying (FSK) time-domain signal based on a preset sampling rate. In some embodiments, the preset sampling rate is determined based on the symbol rate of the FFS time-domain signal and the preset number of sampling points corresponding to each symbol of the FFS time-domain signal.

[0040] Through the above sampling process, the signal receiving device obtains a sampling point sequence, which includes multiple sampling points arranged in chronological order of sampling time. Each sampling point is used to characterize the amplitude value or complex baseband value of the frequency shift keying (FSK) time-domain signal at the corresponding sampling time. Thus, the signal receiving device converts the continuous FFS time-domain signal into a discrete sampling point sequence, which can then be used to perform phase difference extraction, period accumulation, and synchronization position determination.

[0041] Step 120: Determine the phase difference corresponding to each sampling point in the sampling point sequence, and perform signed aggregation of the phase differences in the same period phase according to the repetition period of the frequency shift keying preamble to form a period phase accumulation sequence.

[0042] The phase difference corresponding to a sampling point refers to the phase difference value determined based on the phase change between the sampling point and a reference sampling point. In some embodiments, the reference sampling point can be a sampling point adjacent to the sampling point, or a sampling point spaced apart from the sampling point by a preset number of sampling points.

[0043] In a feasible implementation, for a sequence of sampling points in the form of complex baseband, the phase difference corresponding to any sampling point can be determined based on the phase of the conjugate product of the sampling point and the reference sampling point.

[0044] The repetition period of a frequency-shift keying (FSK) preamble refers to the time length, number of symbols, or number of sampling points corresponding to the repeated symbol patterns in the FPSK preamble. In other words, if the preamble includes symbol segments that are repeated according to a preset pattern, the length of the symbol segment can be used as the repetition period of the preamble. In some implementations, the repetition period can be represented by the number of symbols or the number of sampling points. For example, when each symbol corresponds to N sampling points, and the repeated symbol segments of the preamble include K symbols, the repetition period can correspond to K×N sampling points.

[0045] Phase differences within the same periodic phase refer to phase differences that, when categorizing the phase differences corresponding to each sampling point according to the repetition period of the frequency shift keying preamble, are located within different repetition periods but are in the same relative position to the start position of their respective repetition periods. In other words, if the repetition period of the frequency shift keying preamble is divided into multiple periodic phases, then the phase differences corresponding to sampling points in different repetition periods that correspond to the same periodic phase can be considered to be within the same periodic phase.

[0046] The periodic phase is used to characterize the positional relationship of the phase difference relative to the starting position of its respective repetition period within the period. For example, the periodic phase can be represented by one or more of the following: periodic sequence number, periodic index, periodic sampling position, periodic sign position, or periodic phase state; however, this embodiment of the invention does not limit this representation.

[0047] Signed aggregation refers to the process of retaining the sign of the phase difference when aggregating phase differences and performing algebraic accumulation on multiple phase differences in the same periodic phase. The resulting periodic phase accumulation sequence includes multiple phase accumulation values, each corresponding to a periodic phase and representing the phase difference accumulation result of that periodic phase over multiple repeating periods.

[0048] In some implementations, the signal receiving device can first determine the phase difference corresponding to each sampling point according to the sampling point sequence; then, based on the repetition period of the frequency shift keying preamble, divide each phase difference into the corresponding periodic phase; for multiple phase differences located in different repetition periods but corresponding to the same periodic phase, perform algebraic accumulation while retaining the positive and negative signs of each phase difference to obtain the phase accumulation value corresponding to the periodic phase; finally, combine the phase accumulation values ​​corresponding to each periodic phase according to the order of arrangement of each periodic phase in the repetition period to form a periodic phase accumulation sequence.

[0049] It should be noted that the reason for adopting the above-mentioned signed aggregation method is that frequency shift keying (FSK) preambles have a repetitive structure, and the phase differences at the same periodic phase usually have a consistent or similar structural change trend, while the phase differences corresponding to random noise usually do not have a stable periodic phase pattern. Based on this, when the phase differences at the same periodic phase are signedly accumulated, the structural phase difference corresponding to the preamble can be continuously enhanced at the same periodic phase, while the positive and negative phase differences caused by random noise are more likely to cancel each other out during the accumulation process. This makes the periodic phase accumulation sequence more prominently reflect the periodic peak-valley characteristics of the FSD preamble.

[0050] Step 130: Divide the two phase accumulation values ​​in the periodic phase accumulation sequence that are separated by a preset number into a group, sum the absolute values ​​of the two phase accumulation values ​​in each group to obtain the peak intensity sequence, and perform a signed average on each phase accumulation value in the periodic phase accumulation sequence to obtain the waveform balance value.

[0051] Here, the two phase accumulation values ​​separated by a preset number refer to the two phase accumulation values ​​whose index positions differ by a preset number in the periodic phase accumulation sequence. In some embodiments, the preset number can be determined based on the repetition period of the frequency shift keying preamble; in other embodiments, the preset number can also be determined based on the number of sampling points corresponding to each symbol in the frequency shift keying time domain signal.

[0052] The signal receiving device first divides two phase accumulation values ​​that are spaced a preset number apart in the periodic phase accumulation sequence into a group, resulting in multiple phase accumulation value groups. Then, for any two phase accumulation values ​​in any phase accumulation value group, the absolute values ​​of the two phase accumulation values ​​are calculated to obtain two phase amplitude representations. The two phase amplitude representations are then summed to obtain the peak intensity value corresponding to that phase accumulation value group. Subsequently, the signal receiving device obtains a peak intensity sequence based on the peak intensity values ​​corresponding to the multiple phase accumulation value groups.

[0053] It should be noted that the periodic phase accumulation sequence is divided into groups of two phase accumulation values ​​separated by a predetermined number of intervals. For any pair of phase accumulation values ​​in any group, the absolute values ​​of the two phase accumulation values ​​are calculated separately and then summed. The reason for this is that the repetitive structure of the frequency shift keying preamble in the periodic phase accumulation sequence typically manifests as positive and negative accumulation regions. If the phase accumulation values ​​in different directions are directly summed algebraically, they may cancel each other out, weakening the peak-valley structure corresponding to the preamble. However, by taking the absolute values ​​separately and then summing them, both the positive peak and the negative valley values ​​are included as intensity contributions in the same peak intensity value, thus obtaining a peak intensity sequence that can characterize the significance of the paired peaks and valleys.

[0054] Signed averaging refers to the process of averaging multiple phase accumulation values ​​in a periodic phase accumulation sequence while retaining the positive or negative sign of each phase accumulation value. For multiple phase accumulation values ​​in a periodic phase accumulation sequence, the signal receiving device performs algebraic summation on the multiple phase accumulation values, and then averages the algebraic summation result according to the number of phase accumulation values. The resulting average phase accumulation value is used as the waveform balance value.

[0055] It should be noted that the purpose of performing a signed average of the accumulated values ​​of each phase in the periodic phase accumulation sequence is to obtain the overall bias of the periodic phase accumulation sequence relative to the zero reference. If the positive and negative accumulated portions of the periodic phase accumulation sequence are relatively balanced, the waveform balance value is usually close to the zero reference. If the periodic phase accumulation sequence is affected by unidirectional bias, asymmetric interference, residual frequency offset, or non-preamble signal components, the waveform balance value may be significantly biased towards positive or negative values. Therefore, the waveform balance value can be used to subsequently determine whether the periodic phase accumulation sequence conforms to the positive and negative balance characteristics of frequency shift keying preambles and to reduce the impact of the overall bias on the preamble detection results.

[0056] In a feasible implementation, a signed average of the accumulated values ​​of each phase in the periodic phase accumulation sequence can be performed. This can be achieved by performing a signed weighted average of the accumulated values ​​based on the weights corresponding to each phase accumulation value. Specifically, the signal receiving device, while retaining the positive or negative sign of each accumulated value, multiplies each accumulated value by its corresponding weight to obtain multiple weighted accumulated values. The multiple weighted accumulated values ​​are then algebraically summed, and the summation result is normalized according to the sum of each weight to obtain the phase accumulation weighted average value. This phase accumulation weighted average value is then used as the waveform balance value.

[0057] The weight of each phase accumulation value can be determined based on one or more of the following: sampling position, signal energy, reliability of the phase accumulation value, or window position. For example, a larger weight can be assigned to the phase accumulation value near the center of the period in the periodic phase accumulation sequence, and a smaller weight can be assigned to the phase accumulation value near the edge of the period; or, a larger weight can be assigned to the phase accumulation value with higher signal energy and more stable phase change.

[0058] Step 140: When the maximum value of the peak intensity sequence is greater than the first threshold and the absolute value of the waveform balance value is less than the second threshold, determine the synchronization position of the frequency shift keying preamble based on the periodic phase corresponding to the maximum value.

[0059] The first threshold refers to the intensity threshold used to determine whether there is a sufficiently significant peak response in the peak intensity sequence, and can be used to determine the strength of the maximum value in the peak intensity sequence. In some implementations, the first threshold can be determined based on one or more of the following: the average, median, maximum, minimum, variance, and standard deviation of multiple peak intensity values ​​in the peak intensity sequence.

[0060] In some embodiments, the first threshold is determined based on non-maximum values ​​in the peak intensity sequence. The signal receiving device identifies one or more non-maximum values ​​in the peak intensity sequence, determines the background intensity level of the peak intensity sequence based on the non-maximum values, and determines the first threshold based on the background intensity level. This can make the determination of whether the maximum value is significantly higher than other positions more reliable.

[0061] In other embodiments, the first threshold is determined based on the length of the periodic phase accumulation sequence. Since the length of the periodic phase accumulation sequence is related to the number and distribution of peak intensity values ​​in the peak intensity sequence, the signal receiving device determines different first thresholds for periodic phase accumulation sequences of different lengths, or modifies the first threshold according to the length of the periodic phase accumulation sequence. Thus, the first threshold can be adapted to periodic phase accumulation sequences of different lengths.

[0062] The second threshold is a balance threshold used to determine whether the overall positive and negative bias of the periodic phase accumulation sequence is within the ideal phase range.

[0063] In feasible implementations, the first threshold and the second threshold can be fixed thresholds set based on engineering experience.

[0064] It is easy to understand that the determination of the first threshold and the second threshold can be based on factors such as the hardware characteristics of the receiving device, the communication environment, the signal bandwidth, the sampling parameters, the frequency shift keying preamble structure, and the detection performance requirements. The above embodiments are only illustrative examples. The technical features in each embodiment can be used individually or combined, substituted, or cross-application without conflict.

[0065] After acquiring the peak intensity sequence, the signal receiving device first determines the maximum value in the sequence. Once the maximum value is determined, its position within the sequence is identified. Based on the correspondence between the peak intensity sequence and the periodic phase accumulation sequence, the corresponding periodic phase is determined. When the maximum value is greater than a first threshold and the absolute value of the waveform balance is less than a second threshold, the signal receiving device obtains the synchronization position of the frequency shift keying preamble based on the determined periodic phase.

[0066] It should be noted that when the signal receiving device detects the arrival of the frequency shift keying (FSK) preamble signal, since the phase difference corresponding to the FSK preamble changes approximately sinusoidally with the periodic phase, the periodic phase accumulation sequence formed by the signed aggregation of phase differences within the same periodic phase can essentially represent a complete or approximately complete sinusoidal waveform. When a signed average is performed on multiple phase accumulation values ​​in this periodic phase accumulation sequence, the phase accumulation values ​​corresponding to the positive half-cycle and the negative half-cycle can cancel each other out, making the resulting waveform balance value close to zero.

[0067] Therefore, if the absolute value of the waveform balance value is less than the second threshold, the periodic phase accumulation sequence is determined to satisfy the positive and negative balance characteristics, thus confirming that the received frequency shift keying (FSK) time-domain signal has the phase difference waveform characteristics corresponding to the FFS preamble. Conversely, if the absolute value of the waveform balance value is not less than the second threshold, it indicates that the periodic phase accumulation sequence as a whole has a significant positive or negative bias, and its phase difference waveform does not conform to the sinusoidal balance characteristics corresponding to the FFS preamble. Therefore, the signal receiving device may not determine the currently received FFS time-domain signal as a FFS preamble signal, or may not determine the synchronization position of the FFS preamble based on the periodic phase accumulation sequence.

[0068] It should also be noted that the maximum value of the peak intensity sequence being greater than the first threshold and the absolute value of the waveform balance value being less than the second threshold correspond to different detection dimensions and cannot be replaced by comparing a single accumulated phase difference with a single threshold. The former condition is used to confirm that the local peak-valley responses of the preamble are sufficiently significant, while the latter condition is used to confirm that the phase changes within the complete repetition period satisfy a positive-negative balance relationship. Only when both conditions are met simultaneously can the synchronization position be determined based on the periodic phase corresponding to the maximum value. This allows for the exclusion of interference signals that only have local spikes but whose overall distribution does not conform to the preamble pattern, as well as signals that only have an overall bias but lack an effective peak-valley structure.

[0069] The wireless signal synchronization method in a power line carrier multimode communication system provided by the present invention samples the received frequency shift keying (FSK) time-domain signal to obtain a sampling point sequence, and makes each symbol of the FFS time-domain signal correspond to a preset number of sampling points. This provides a unified and stable data foundation for subsequent phase difference calculation and aggregation by repetition period, avoiding the impact of inconsistent sampling scales on synchronization judgment. Based on this, by determining the phase difference corresponding to each sampling point in the sampling point sequence, and according to the repetition period of the FFS preamble, the phase differences in the same period phase are signedly aggregated to form a periodic phase accumulation sequence. This allows phase differences conforming to the preamble repetition pattern to accumulate and strengthen in the same period phase, while noise or interference that does not conform to this repetition pattern is difficult to accumulate stably, thereby improving the saliency of the preamble features and enhancing the anti-noise and anti-interference capabilities of signal synchronization detection. Furthermore, the periodic phase accumulation... Two phase summation values ​​separated by a preset number in the sequence are grouped together. The absolute values ​​of the two phase summation values ​​in each group are summed to obtain the peak intensity sequence. A signed average of the phase summation values ​​in the periodic phase summation sequence is then performed to obtain the waveform balance value. This allows for the simultaneous acquisition of the local peak intensity and the overall positive and negative balance of the preamble, improving the detection capability of the true preamble and suppressing false detections caused by non-target signals with only local peaks or significant overall bias. Finally, when the maximum value of the peak intensity sequence is greater than a first threshold and the absolute value of the waveform balance value is less than a second threshold, the synchronization position of the frequency shift keying preamble is determined based on the periodic phase corresponding to the maximum value. The synchronization result can be jointly constrained by the local peak intensity and the overall balance, making the determination of the synchronization position more accurate and reliable, thereby reducing the probability of false synchronization and improving the accuracy of frequency shift keying signal synchronization detection and the reliability of subsequent data demodulation.

[0070] In some related technical solutions, the relationship between phase differences can be used for signal synchronization. For example, the synchronization position can be determined by calculating the difference between the phase difference corresponding to a certain sampling point and another phase difference separated by a predetermined sampling interval, and by determining whether this difference meets a preset condition. The principle is that the phase difference corresponding to a certain sampling point and another phase difference separated by a predetermined sampling interval can reflect the frequency offset of the frequency shift keying signal. When the frequency offset meets the preset condition, the signal receiving device can determine the synchronization position of the frequency shift keying signal accordingly.

[0071] However, the aforementioned technical solutions mainly focus on the synchronous judgment of the phase difference relationship between different times, that is, using the relative change of the phase difference to estimate the synchronization state.

[0072] It should be further explained that in a phase difference-based synchronization process, the difference between two first phase differences separated by a predetermined sampling interval can be used to form a second phase difference. Then, the second phase differences within one symbol interval before and after the current candidate position are accumulated, and the difference between the two accumulated results is calculated. Finally, the single accumulated phase difference is compared with a threshold. The statistical range of this process moves with the candidate position, and the resulting judgment value mainly reflects the relative change between the two local symbol intervals.

[0073] The periodic phase accumulation sequence described in this embodiment is not obtained by further differentiating the first phase difference, nor is it the difference between the accumulation results of two consecutive local symbol intervals. Instead, it is obtained by signedly aggregating the first phase differences that span multiple repetition cycles and are in the same periodic phase according to the complete frequency shift keying preamble repetition cycle. The resulting periodic phase accumulation sequence retains the positive and negative polarities and amplitude distribution of each periodic phase within a complete repetition cycle, enabling the subsequent construction of peak intensity sequences representing local peak-valley responses and waveform balance values ​​representing overall positive and negative biases from the same periodic phase accumulation sequence.

[0074] For wireless preambles with periodic repetition structures, sampling points at the same periodic phase position in different repetition periods usually correspond to the same or similar phase evolution positions. Therefore, the phase differences obtained from these sampling points typically have similar trends, symbol polarities, and amplitude distributions under ideal conditions; even when affected by factors such as noise, channel fading, transient interference, or residual frequency offset, they may still retain a certain degree of periodic correlation and statistical consistency.

[0075] In other words, the phase difference at the same phase position in multiple repetition cycles has the characteristic of accumulating according to the corresponding periodic position, which manifests as a periodic phase accumulation relationship. This feature corresponds to the distribution of multiple phase positions within a complete preamble cycle, and can characterize the phase change pattern within the cycle. This is beneficial for reflecting the positive and negative sign relationship, relative amplitude relationship, and overall balance relationship of the frequency shift keying signal preamble, improving the stability of the preamble detection feature, and thus determining the synchronization position of the frequency shift keying time domain signal under the premise that the preamble can be accurately detected.

[0076] Based on this, in some embodiments, the frequency shift keying preamble includes two alternating preamble symbols, with each repetition period corresponding to two preamble symbols. According to the repetition period of the frequency shift keying preamble, the phase differences within the same periodic phase are signedly aggregated to form a periodic phase accumulation sequence. Specifically, this includes: determining twice the preset number of periodic phases based on the repetition period; for any periodic phase, accumulating the phase differences corresponding to each sampling point in the sampling point sequence that is within the corresponding periodic phase and has an interval twice the preset number between adjacent sampling points to obtain the phase accumulation value corresponding to the corresponding periodic phase; and combining the corresponding phase accumulation values ​​according to the order of arrangement of each periodic phase within the repetition period to obtain the periodic phase accumulation sequence.

[0077] The frequency shift keying (FSK) preamble includes two alternating preamble symbols. Specifically, the FSD preamble is formed by alternating preamble symbols with different frequency characteristics or different phase change trends. For example, the first preamble symbol and the second preamble symbol may appear alternately. For instance, the first preamble symbol may be 1 and the second preamble symbol may be 0, or the first preamble symbol may be 0 and the second preamble symbol may be 1.

[0078] A repetition period corresponds to two preamble symbols, meaning that the first and second preamble symbols are adjacent to each other as a repetition unit, which appears periodically in the preamble code.

[0079] Periodic phase refers to the relative position obtained by dividing the sampling position within a repetition period. If the preset number represents the number of sampling points corresponding to one preamble symbol, since one repetition period includes two preamble symbols, one repetition period can correspond to twice the preset number of periodic phases.

[0080] It should be noted that one repetition period can correspond to twice the preset number of periodic phases. This ensures that twice the preset number of periodic phases allows the repetition period to completely cover the repetition unit consisting of two adjacent preamble symbols. Since the first and second preamble symbols in the frequency shift keying preamble alternate, they typically have different frequency characteristics or phase change trends. If only the preset number corresponding to a single preamble symbol is used as the period length, it may not be possible to simultaneously characterize the alternation relationship between the two preamble symbols. If a larger multiple of the preset number is used as the period length, multiple repetition units may be introduced within one period, leading to redundancy in the periodic phase division, reducing the correspondence between the same periodic phase positions, and increasing the computational load of subsequent accumulation and detection processing.

[0081] Therefore, by setting a repetition period to twice the number of periodic phases, the phase change characteristics corresponding to the first preamble symbol and the second preamble symbol can be retained respectively during the same periodic phase accumulation process, thereby more accurately reflecting the periodic repetition structure of the frequency shift keying preamble.

[0082] After obtaining the sampling point sequence, the signal receiving device determines the phase difference corresponding to each sampling point based on the phase information corresponding to each sampling point in the sampling point sequence. If the number of sampling points corresponding to a preamble symbol is a preset number N, and the repetition period of the frequency shift keying preamble includes two alternating preamble symbols, then one repetition period can be divided into 2N periodic phases.

[0083] For the i-th periodic phase (0 ≤ i < 2N, where i is an integer), the signal receiving device can select multiple sampling points in the i-th periodic phase from the sampling point sequence and determine the phase difference corresponding to the multiple sampling points. For example, sampling points with indices i, i+2N, i+4N, etc., can be selected, or the phase difference data corresponding to that index can be selected. In other words, the interval between two adjacent selected data in the sampling point sequence is 2N. Subsequently, the signal receiving device performs a signed accumulation of these phase differences in the same periodic phase to obtain the phase accumulation value corresponding to the i-th periodic phase; the phase accumulation values ​​corresponding to each periodic phase are combined according to the order of arrangement within the repetition period to obtain the periodic phase accumulation sequence.

[0084] The signal receiving device can perform the above processing on each periodic phase from 0 to 2N-1, obtaining 2N phase accumulation values. Then, the signal receiving device combines these 2N phase accumulation values ​​sequentially according to the order of the periodic phases within the repetition period, forming a periodic phase accumulation sequence. This periodic phase accumulation sequence can characterize the cumulative phase change of the frequency shift keying preamble on different periodic phases within one repetition period.

[0085] For example, with a preset quantity N of 8, one repetition cycle corresponds to 16 cycle phases. The signal receiving device can perform signed accumulation on the phase differences at the 0th cycle phase, the 1st cycle phase, ..., the 15th cycle phase to obtain 16 phase accumulation values, and combine them into a cycle phase accumulation sequence in the order of the 0th cycle phase to the 15th cycle phase.

[0086] Thus, the signal receiving device obtains a cumulative sequence of periodic phases corresponding to multiple periodic phase positions within a repetition period. This cumulative sequence can be used to characterize the periodic phase change distribution of the frequency shift keying (FSK) preamble and serve as a characteristic basis for determining the synchronization position of subsequent preambles, rather than being directly used for signal synchronization. This is because the cumulative sequence reflects the accumulated phase difference at each periodic phase position within a repetition period. This sequence can be used to determine which periodic phase positions better conform to the periodic phase change pattern of the FSK preamble, but the sequence itself is merely a statistical result of the periodic phase characteristics.

[0087] In the above embodiments, by determining a periodic phase twice the number of preset phases based on the repetition period corresponding to two alternating preamble symbols in the frequency shift keying preamble, and by performing signed accumulation on the phase differences corresponding to sampling points in the same periodic phase with an adjacent interval of twice the number of preset phases, the periodic enhancement of the phase change characteristics on the same periodic phase is achieved, thereby reducing the random fluctuations caused by noise, frequency offset or phase disturbances affecting a single sampling point or a single phase difference.

[0088] In the detection of frequency shift keying (FSK) preambles, threshold judgments are typically used to distinguish valid preamble features from noise or interference features. However, if the same threshold is used for different judgment stages or different detection indicators, it may be difficult to balance detection sensitivity and false positive suppression capability. For example, if the threshold is set too high, preambles in weak signal scenarios may be missed; if the threshold is set too low, noise fluctuations may be misjudged as preamble features.

[0089] In some embodiments, the second threshold is less than the first threshold; the preset number is 16, and the frequency shift keying preamble includes preamble symbols arranged alternately with 0 and 1.

[0090] In some implementations, when performing frequency shift keying (FSK) preamble detection, the signal receiving device pre-configures a first threshold and a second threshold, ensuring that the second threshold is less than the first threshold. This is because the first threshold is used to determine whether a sufficiently significant peak response exists in the peak intensity sequence, i.e., to measure whether the maximum value of the peak intensity sequence has a sufficiently strong prominence; the second threshold is used to determine whether the overall positive and negative bias of the periodic phase accumulation sequence is within the ideal phase range, i.e., to measure whether the periodic phase accumulation sequence satisfies the phase balance characteristics corresponding to the preamble. Since the maximum value of the peak intensity sequence is typically used to characterize the concentration of the preamble detection response, its value needs to reach a high level to be considered as having a reliable preamble peak; while the overall positive and negative bias of the periodic phase accumulation sequence mainly characterizes the balance between the positive and negative phase accumulation results, the smaller the bias, the closer it is to the ideal phase distribution.

[0091] Therefore, setting the second threshold used for bias judgment to be less than the first threshold used for peak intensity judgment allows the two thresholds to be adapted to detection indicators with different physical meanings and different numerical scales, thereby improving the rationality and accuracy of preamble decision.

[0092] In other implementations, the second threshold is less than the first threshold, and the second threshold is not zero. That is, the second threshold may not be strictly zero, but is set as a non-zero balanced threshold that allows for a certain positive and negative bias in the periodic phase accumulation sequence. Therefore, when determining whether the overall positive and negative bias of the periodic phase accumulation sequence is within the ideal phase range, the signal receiving device can allow for a certain range of deviation in the detection result, thereby avoiding misjudgments caused by noise interference, frequency shift, or sampling errors, and improving the robustness of frequency shift keying preamble detection.

[0093] In some embodiments, the signal receiving device can set a preset quantity of 16, that is, set the number of sampling points or basic processing units corresponding to one preamble symbol to 16. Since the frequency shift keying preamble includes preamble symbols arranged alternately with 0s and 1s, an adjacent 0 symbol and a 1 symbol can constitute a repetition period, which corresponds to 32 sampling points or 32 basic processing units. The signal receiving device can perform periodic phase division, phase difference accumulation, or detection window matching processing on the sampling point sequence based on the repetition period of these 32 sampling points.

[0094] For example, a signal receiving device can process the received sample point sequence in such a way that every 16 sample points correspond to one preamble symbol, and determine that every two preamble symbols constitute a repeating unit according to the periodic pattern corresponding to the alternating arrangement of 0, 1, 0, 1. Subsequently, the signal receiving device can determine 32 periodic phases within this repeating unit and accumulate the phase differences of phases within the same periodic phase.

[0095] In the above embodiments, by setting the second threshold to be less than the first threshold, the signal receiving device can employ decision criteria of varying stringency at different detection stages or under different detection conditions. This achieves hierarchical screening and reliable confirmation of preamble features, thus balancing detection sensitivity in weak signal scenarios and false detection suppression capability in complex noise scenarios. Simultaneously, by limiting the preset quantity to 16 and defining the frequency shift keying preamble as including preamble symbols arranged in alternating 0 and 1, the signal receiving device can perform phase difference processing according to a fixed symbol length and a defined repetition period, improving the stability of the preamble detection results.

[0096] When signal receiving equipment performs frequency shift keying (FSK) preamble detection, it typically needs to determine the presence of a preamble based on the phase change characteristics of the received signal. However, directly judging based on the instantaneous phase of a single sampling point is easily affected by noise, frequency offset, amplitude fluctuations, or phase abrupt changes, resulting in poor stability of the obtained phase characteristics and thus affecting the accuracy of preamble detection.

[0097] Based on this, in some embodiments, the phase difference corresponding to each sampling point in the sampling point sequence is determined respectively, specifically including: for any sampling point, determining a reference sampling point that is separated from the corresponding sampling point by a phase measurement interval from the sampling point sequence; performing conjugate multiplication on the complex sampling value of the corresponding sampling point and the complex sampling value of the reference sampling point, and determining the phase difference corresponding to the corresponding sampling point based on the conjugate multiplication result.

[0098] Among them, the sampling point sequence refers to the sequence formed by arranging multiple sampling points obtained by the signal receiving device after sampling the received wireless signal in chronological order.

[0099] Complex sample values ​​refer to the complex form of sample values ​​composed of the in-phase and quadrature components corresponding to the sample point; the phase measurement interval refers to the number of sample point intervals used to determine the phase difference between two sample points. In feasible implementations, the phase measurement interval can be determined based on one or more of the modulation parameters, sampling rate, symbol length, or detection accuracy requirements of the frequency shift keying time domain signal.

[0100] Conjugate multiplication refers to the process of multiplying the complex sample value of one sampling point with the conjugate value of the complex sample value of another sampling point to obtain a complex result that can characterize the phase change relationship between the two sampling points.

[0101] The signal receiving device can process each sampling point in the sampling point sequence sequentially according to the order of the sampling point sequence. For any sampling point currently being processed, the signal receiving device can search for a reference sampling point in the sampling point sequence that is separated from the current sampling point by a preset phase measurement interval. For example, if the current sampling point is the [number missing]th sampling point... There are sampling points, and the phase measurement interval is . Then the first The sampling point or the first Each sampling point is designated as a reference sampling point, and the specific direction can be determined based on the implementation method of the detection algorithm.

[0102] After determining the reference sampling point, the signal receiving device can acquire the complex sample value of the current sampling point and the complex sample value of the reference sampling point. Assume the complex sample value of the current sampling point is x(n), and the complex sample value of the reference sampling point is... Then the signal receiving device can calculate and The product between the conjugate values, i.e., calculating This yields the result of conjugate multiplication. Among them, Indicates taking The conjugate value; the phase of the conjugate multiplication result can reflect the phase change of the current sampling point relative to the reference sampling point. Therefore, the signal receiving device can determine the phase difference corresponding to the current sampling point based on the phase angle of the conjugate multiplication result.

[0103] In one feasible implementation, the signal receiving device can determine the phase angle of the conjugate multiplication result through arctangent operation and use this phase angle as the phase difference corresponding to the corresponding sampling point. In another feasible implementation, the signal receiving device can also determine the phase difference sign or phase difference category corresponding to the corresponding sampling point based on one or more of the sign relationship, magnitude relationship, or quantization result of the real and imaginary parts of the conjugate multiplication result, thereby reducing computational complexity.

[0104] In the above embodiments, by determining a reference sampling point separated from any sampling point by a phase measurement interval, and performing conjugate multiplication on the complex sampled value of the corresponding sampling point and the complex sampled value of the reference sampling point, the signal receiving device can determine the phase difference based on the relative phase relationship between the two sampling points, rather than relying solely on the instantaneous phase of a single sampling point. This effectively reduces the impact of received signal amplitude variations on phase difference calculation and more accurately extracts the phase change characteristics of the frequency shift keying signal, thereby improving the stability and accuracy of frequency shift keying preamble detection.

[0105] When determining the phase difference corresponding to a sampling point, signal receiving equipment typically needs to pre-set the phase measurement interval. If the phase measurement interval is set too small, the phase change between two sampling points will not be obvious enough and will be easily masked by noise or quantization errors, resulting in insufficient phase difference discrimination. If the phase measurement interval is set too large, it may span too many symbols or sampling points, causing the phase difference to be affected by symbol jumps, frequency offset accumulation, or channel changes, resulting in the phase difference not accurately reflecting the modulation characteristics of the frequency shift keying time domain signal.

[0106] Based on this, in some embodiments, the phase measurement interval is the ratio of a preset number to a scaling factor, which is determined based on the modulation index of the frequency shift keying time-domain signal.

[0107] The phase measurement interval refers to the number of sampling point intervals in the sampling point sequence used to determine the distance between the current sampling point and the reference sampling point, and it is used to control the time span of phase difference measurement. In some implementations, the preset number is determined based on one or more of the following: sampling rate, symbol period, preamble period, detection window length, or hardware implementation requirements.

[0108] The scaling factor is a factor used to proportionally adjust a preset quantity. It can be used to characterize the difference in phase change rate or frequency offset amplitude under different modulation indices. The modulation index is a parameter relating the frequency offset to the symbol rate in a frequency shift keying (FSK) time-domain signal. It reflects the degree of frequency separation of the FFS signal under different symbol states and the rate at which the phase changes over time.

[0109] The signal receiving device can first acquire or determine the modulation index corresponding to the frequency shift keying time domain signal. In some embodiments, the modulation index can be predetermined based on the communication protocol; in other embodiments, the modulation index is determined based on one or more of the following: channel configuration, modulation scheme identifier, or received signal parameters.

[0110] Subsequently, the signal receiving device can determine the scaling factor based on the modulation index. In feasible implementations, the scaling factor is positively correlated with the modulation index. In other words, when the modulation index is large, the frequency shift of the frequency shift keying time-domain signal is large, and the phase changes rapidly with time, allowing for a larger scaling factor to be determined; conversely, when the modulation index is small, the frequency shift is small, and the phase changes slowly with time, allowing for a smaller scaling factor to be determined.

[0111] After determining the scaling factor, the signal receiving device can divide a preset number by the scaling factor to obtain the phase measurement interval. In other words, when the modulation index and scaling factor are large, the phase measurement interval is reduced accordingly to avoid phase aliasing or cross-symbol errors caused by excessive phase change span; when the modulation index and scaling factor are small, the phase measurement interval is increased accordingly so that sufficient detectable phase change can accumulate between two sampling points. Therefore, the signal receiving device can adapt the sampling point interval used for phase difference measurement according to the modulation index of the frequency shift keying time-domain signal.

[0112] In one feasible implementation, the preset quantity can be the number of sampling points determined based on the sampling rate and symbol period, and the scaling factor can be an integer, fraction, or floating-point number obtained by mapping the modulation index. In some implementations, if the ratio of the preset quantity to the scaling factor is not an integer, the signal receiving device can perform rounding, squaring, or limiting on the ratio to obtain a phase measurement interval that can be used for sampling point indexing.

[0113] In other implementations, the phase measurement interval is greater than a preset minimum interval and less than a preset maximum interval, in order to avoid insufficient noise immunity due to an excessively small phase measurement interval, or reduced phase difference measurement accuracy due to an excessively large phase measurement interval that spans too many sampling points.

[0114] For example, the phase measurement interval can be calculated using the following formula: (1) Where N represents the phase measurement interval, and Ns represents the number of sampling points corresponding to each frequency shift keying symbol. This is the scaling factor.

[0115] In some implementations, the scaling factor is calculated using the following formula: (2) in, Indicates the modulation index; in some implementations... The value range is from 0 to 1, and can be set according to the actual communication scenario. , These are preset parameters. In feasible implementations, This makes the calculation of the scaling factor more standardized, facilitating parameter configuration and implementation; in other feasible implementations, and It can also be set to different values ​​to adapt to different modulation schemes, channel conditions, or system requirements. For example, It can be a base parameter of 2, e, 10 or other values ​​greater than 1, used to control the exponential mapping base of the scaling factor; It can be 1, 2, 3 or other positive integers, used to adjust the degree of influence of the modulation index on the scaling factor.

[0116] Figure 2 This is a schematic diagram illustrating how the present invention determines the phase difference corresponding to sampling points under different phase measurement intervals in some embodiments. For example... Figure 2As shown, the horizontal axis represents the sampling point number, and the vertical axis represents the phase difference corresponding to the sampling point. With a modulation index of 0.5, the scaling factor corresponding to the frequency shift keying time-domain signal corresponds to the modulation index, thus changing the actual sampling point span obtained after the phase measurement interval is the ratio of a preset number to the scaling factor. Because the sampling point span corresponding to the phase measurement interval is different, the time span between the two sampling points involved in the phase difference calculation is different, resulting in different accumulated phase changes and ultimately phase differences of different amplitudes. Figure 2 The three curves in the diagram represent the phase difference changes at each sampling point when the phase measurement intervals are N1, N2, and N3, respectively. N1, N2, and N3 can be different sampling point intervals determined by a preset number and scaling factor, with N1 < N2 < N3. Figure 2 It can be seen that when the phase measurement interval is N1, the time span between the current sampling point and the reference sampling point is small, the cumulative phase change is small, and therefore the determined phase difference amplitude is small. When the phase measurement interval is N2, the time span between the current sampling point and the reference sampling point increases, the cumulative phase change increases, and therefore the determined phase difference amplitude increases accordingly. When the phase measurement interval is N3, the time span between the current sampling point and the reference sampling point further increases, the cumulative phase change further increases, and therefore the determined phase difference amplitude further increases. Therefore, the phase measurement interval affects the amplitude and detectability of the phase difference corresponding to the sampling point by changing the time span of the sampling points involved in the phase difference calculation.

[0117] Figure 3 This is a schematic diagram illustrating the determination of the phase difference corresponding to the sampling point under different phase measurement intervals in other embodiments of the present invention. For example... Figure 3 As shown, the horizontal axis represents the sampling point number, and the vertical axis represents the phase difference corresponding to the sampling point. When the modulation index is 1, the scaling factor corresponding to the frequency shift keying time domain signal changes, thus changing the actual sampling point span corresponding to the phase measurement interval determined by the ratio of the preset number to the scaling factor. Since the phase change pattern of the signal when the modulation index is 1 is different from that when the modulation index is 0.5, different phase measurement intervals will cause the sampling points involved in the phase difference calculation to fall into different phase change intervals, thus causing the phase difference corresponding to the sampling point to change not only in amplitude but also in its change pattern. Figure 3 The three curves in the diagram represent the phase difference changes at each sampling point when the phase measurement intervals are N1, N2, and N3, respectively. N1, N2, and N3 can be different sampling point intervals determined by a preset number and scaling factor, with N1 < N2 < N3. Figure 3It can be seen that when the phase measurement interval is N1, the phase difference corresponding to each sampling point exhibits a small-amplitude periodic change with the sampling point number; when the phase measurement interval is N2, the phase difference corresponding to each sampling point varies between positive and negative phase differences, and shows an approximately plateau-like change within some sampling point intervals; when the phase measurement interval is N3, the phase difference corresponding to each sampling point exhibits a larger-amplitude periodic change. Therefore, with a modulation index of 1, the phase measurement interval affects the amplitude and change pattern of the phase difference corresponding to the sampling point by changing the phase change interval spanned by the sampling point, thus affecting the detectability of the phase difference.

[0118] Therefore, different modulation indices lead to different scaling factors, which in turn result in different actual sampling point spans corresponding to the phase measurement interval. These different sampling point spans, in turn, affect the phase difference corresponding to each sampling point. In this embodiment of the invention, the signal receiving device can determine the scaling factor based on the modulation index of the frequency shift keying (FSK) time-domain signal, and determine the phase measurement interval based on the ratio of a preset quantity to the scaling factor. This allows the phase measurement interval to adaptively adjust as the modulation index changes. In this way, when the modulation index is small, the phase measurement interval can be increased to accumulate sufficient detectable phase changes; when the modulation index is large, the phase measurement interval can be decreased to avoid excessively large phase change spans that could introduce phase aliasing or cross-symbol errors, thereby improving the accuracy and robustness of phase difference acquisition.

[0119] In the above embodiments, by setting the phase measurement interval to the ratio of a preset number to a scaling factor, and by determining the scaling factor based on the modulation index of the frequency shift keying time domain signal, the signal receiving device can adaptively adjust the phase difference measurement span according to the phase change rate under different modulation indices, thereby improving the accuracy, robustness, and versatility of frequency shift keying preamble detection under different modulation parameters.

[0120] In related technologies, the synchronization position of the frequency shift keying (FSK) preamble is typically determined by correlation peaks or energy peaks. While this method is simple to implement, its synchronization result relies heavily on the position and amplitude characteristics of a single peak. When the received signal is in a low signal-to-noise ratio (SNR) environment, or when there are frequency offsets, phase disturbances, channel fading, or strong preamble repetition structures, the correlation peaks or energy peaks may shift, broaden, split, or exhibit local spurious peaks, leading to inaccurate synchronization position determination or even false detections. Especially when the preamble has periodic repetition characteristics, a single peak is easily affected by local abnormal disturbances, making it difficult to stably reflect the true starting position of the preamble, thus affecting the demodulation accuracy of subsequent FFS signals and overall reception reliability.

[0121] Based on this, in some embodiments, the synchronization position of the frequency shift keying preamble is determined according to the periodic phase corresponding to the maximum value. Specifically, this includes: determining a set of phase accumulation values ​​corresponding to the maximum value; determining the positive peak phase or negative peak phase of the frequency shift keying preamble according to the periodic phase corresponding to the corresponding set of phase accumulation values; and determining the sampling position corresponding to the positive peak phase or negative peak phase as the synchronization position.

[0122] Among them, the phase accumulation value refers to the value obtained by accumulating the phase difference or phase correlation results corresponding to multiple sampling points, which is used to characterize the degree of phase change accumulation within the corresponding sampling interval.

[0123] A positive peak phase refers to the phase position where the accumulated phase value is greater than zero and reaches a local maximum; or the phase position where the accumulated phase value is less than zero and reaches a local minimum. The sampling positions corresponding to positive or negative peak phases can be used as synchronization positions for frequency shift keying (FSK) preambles. A periodic phase refers to the phase distribution of the accumulated phase value within the periodic structure of a FSK preamble, used to characterize the peak position and variation pattern of phase changes within one period.

[0124] The signal receiving device can first sample the received frequency shift keying (FSK) time-domain signal and determine the phase difference corresponding to multiple sampling points based on the phase measurement interval. Subsequently, the signal receiving device can accumulate the phase differences corresponding to the multiple sampling points to obtain multiple phase accumulation values, and determine the maximum value from these values. Since the maximum value can reflect the position or interval where the preamble phase change is most significant, the signal receiving device can further determine a set of phase accumulation values ​​corresponding to this maximum value. In some embodiments, the set of phase accumulation values ​​corresponding to the maximum value may include multiple phase accumulation values ​​near the location of the maximum value, or multiple phase accumulation values ​​with the same or similar periodic relationship to the maximum value.

[0125] Furthermore, the signal receiving device can determine the periodic phase corresponding to each set of phase accumulation values, and determine the positive or negative peak phase corresponding to the frequency shift keying preamble based on the distribution of each periodic phase within a preamble period. For example, when the set of phase accumulation values ​​exhibits a positive peak characteristic in the periodic phase, the signal receiving device can determine the corresponding periodic phase as a positive peak phase; when the set of phase accumulation values ​​exhibits a negative peak characteristic in the periodic phase, the signal receiving device can determine the corresponding periodic phase as a negative peak phase.

[0126] The signal receiving device determines the sampling position corresponding to the positive or negative peak phase based on the correspondence between the positive or negative peak phase and the sampling point number, and determines the sampling position as the synchronization position of the frequency shift keying preamble.

[0127] In the above embodiments, by first determining a set of phase accumulation values ​​corresponding to the maximum value, and then determining the positive peak phase or negative peak phase of the frequency shift keying preamble based on the periodic phase corresponding to the set of phase accumulation values, the error caused by determining the synchronization position based solely on the position of a single maximum value can be avoided. This can improve the accuracy and stability of determining the synchronization position of the frequency shift keying preamble, thereby improving the reliability of subsequent frequency shift keying signal demodulation.

[0128] In frequency shift keying (FSK) signals, sign changes cause different phase change trends at sampling points. For example, in related techniques, extreme points of phase change can be determined by the change characteristics in the phase difference sequence, and the phase change range reflected by these extreme points can be used to track the frequency offset or sampling offset state of the received signal. Since extreme points usually correspond to the locations where the phase change trend changes, they can reflect the phase change over time in the effective signal to a certain extent.

[0129] However, in the above processing, symbol decision is primarily used to identify boundary positions or trend transition positions during phase changes. While extreme points can correspond to endpoint features in the frequency shift keying (FSK) symbol change process, the decision information they correspond to mainly reflects the state of the phase change interval, and is subsequently used in signal state adjustment processes such as frequency offset tracking and sampling frequency offset tracking. For scenarios requiring the recovery of the data content carried by the FFS signal, obtaining only the extreme points or interval boundaries of the phase change is insufficient to determine the specific values ​​of each data symbol in the symbol timing after the synchronization position.

[0130] Based on this, in some embodiments, the method provided by the present invention further includes: determining multiple symbol decision sampling points sequentially from the sampling point sequence according to a preset number, based on the synchronization position; determining the symbol decision result corresponding to each symbol decision sampling point according to the positive or negative sign of the phase difference corresponding to each symbol decision sampling point; and obtaining a symbol decision sequence according to the symbol decision result corresponding to the timing combination of each symbol decision sampling point.

[0131] The synchronization position refers to the sampling position determined by the peak phase of the phase accumulation value corresponding to the frequency shift keying preamble. This synchronization position is used as the time reference for subsequent symbol decision.

[0132] The preset quantity refers to the number of symbols that need to be decided after the synchronization position. In feasible implementations, the preset quantity can be determined based on the number of data symbols to be decided in the frequency shift keying signal.

[0133] The symbol decision sampling point refers to the sampling point determined from the sampling point sequence based on the synchronization position and the sampling point interval corresponding to the symbol period; positive or negative sign refers to the direction of phase change represented by the positive or negative phase difference corresponding to the symbol decision sampling point. In frequency shift keying signals, this direction of phase change has a corresponding relationship with the symbol value.

[0134] The symbol decision result refers to the symbol value determined by the signal receiving device based on the positive or negative sign of the phase difference corresponding to the symbol decision sampling point; the symbol decision sequence refers to the sequence obtained by the signal receiving device by combining multiple symbol decision results sequentially according to the time sequence of multiple symbol decision sampling points in the sampling point sequence.

[0135] After determining the synchronization position of the frequency shift keying preamble, the signal receiving device uses this synchronization position as the reference for determining subsequent symbol decision sampling points. Based on the preset symbol interval, sampling rate, and the number of sampling points corresponding to each symbol, the device sequentially determines multiple symbol decision sampling points from the sampling point sequence. For example, starting from the synchronization position, the signal receiving device can sequentially determine the first symbol decision sampling point, the second symbol decision sampling point, and so on, according to the sampling point interval corresponding to one symbol period, until a preset number of symbol decision sampling points are determined.

[0136] For each symbol decision sampling point, the signal receiving device can determine the phase difference corresponding to that symbol decision sampling point. In some embodiments, the signal receiving device can determine the phase change between that symbol decision sampling point and another sampling point with a preset phase measurement interval as the phase difference corresponding to that symbol decision sampling point.

[0137] Subsequently, the signal receiving device can determine the sign of the phase difference and, based on a preset correspondence between the sign and the symbol value, determine the symbol decision result corresponding to the symbol decision sampling point. In feasible implementations, when the phase difference is greater than zero, the signal receiving device can determine that the symbol decision sampling point corresponds to a first symbol value; when the phase difference is less than zero, the signal receiving device can determine that the symbol decision sampling point corresponds to a second symbol value. In other feasible implementations, when the phase difference is equal to zero, or the absolute value of the phase difference is less than a preset threshold, the signal receiving device can determine the symbol decision result corresponding to the current symbol decision sampling point based on the symbol decision results corresponding to adjacent symbol decision sampling points, the symbol decision result corresponding to the previous symbol decision sampling point, or preset decision rules.

[0138] After obtaining the symbol decision results corresponding to multiple symbol decision sampling points, the signal receiving device can combine the multiple symbol decision results according to the timing of the multiple symbol decision sampling points in the sampling point sequence to obtain a symbol decision sequence. In some embodiments, the symbol decision sequence can be used to represent the symbol information carried in the received frequency shift keying signal, and can also be further used for bit mapping, frame parsing, verification, or subsequent data processing.

[0139] In the above embodiments, by sequentially determining multiple symbol decision sampling points based on the synchronization position, and determining the symbol decision result according to the positive or negative sign of the phase difference corresponding to each symbol decision sampling point, the symbol decision sampling points can be time-aligned with the symbol to be decided, and the symbol decision can be completed using the phase change direction. Then, the symbol decision results are combined according to the time sequence to obtain the symbol decision sequence. Therefore, the risk of misjudgment caused by the offset of symbol decision sampling points can be reduced, complex calculations can be reduced, and the accuracy and processing efficiency of symbol decision can be improved.

[0140] In related technologies, symbol decision mainly relies on the phase difference corresponding to a single symbol decision sampling point, and directly determines the symbol decision result based on the sign of this phase difference. In other words, this type of related scheme focuses on the local phase change at the symbol decision sampling point, without fully utilizing the phase evolution information reflected by multiple sampling points within the symbol interval.

[0141] Because the phase difference at a single sampling point is easily affected by factors such as noise, residual frequency offset, sampling clock jitter, symbol boundary offset, and instantaneous channel disturbances, the positive and negative symbols may flip abnormally, leading to inconsistencies between the symbol decision result and the true symbol. Especially in low signal-to-noise ratio scenarios, the single-point decision method is highly sensitive to local phase disturbances and lacks decision stability. Therefore, relying solely on the phase difference of a single symbol decision sampling point makes it difficult to stably characterize the overall phase change trend of the symbol in complex receiving environments.

[0142] Based on this, in some embodiments, the symbol decision result corresponding to each symbol decision sampling point is determined according to the positive or negative sign of the phase difference corresponding to each symbol decision sampling point. Specifically, this includes: taking any symbol decision sampling point as the center, selecting multiple decision reference points from the sampling point sequence with an odd total number; counting the number of positive phase differences and negative phase differences among the phase differences corresponding to the multiple decision reference points; when the number of positive phase differences is greater than the number of negative phase differences, determining the symbol decision result corresponding to the corresponding symbol decision sampling point as the first value; when the number of negative phase differences is greater than the number of positive phase differences, determining the symbol decision result corresponding to the corresponding symbol decision sampling point as the second value.

[0143] Among them, the decision reference point refers to the sampling point selected from the sampling point sequence with the symbol decision sampling point as the center, which is used to assist in determining the symbol decision result.

[0144] Furthermore, the total number of decision reference points is odd because an odd number of decision reference points can effectively prevent the number of positive phase differences from being equal to the number of negative phase differences.

[0145] A positive phase difference refers to a phase difference greater than zero corresponding to the decision reference point, while a negative phase difference refers to a phase difference less than zero corresponding to the decision reference point. The first and second values ​​represent the two symbol values ​​corresponding to different phase change directions in the frequency shift keying signal, respectively. In some implementations, the first value may be, for example, 1, and the second value may be, for example, 0.

[0146] After determining any symbol decision sampling point, the signal receiving device can select multiple decision reference points in the sampling point sequence, either forward, backward, or both, centered on that symbol decision sampling point. For example, the signal receiving device can select the symbol decision sampling point itself and several adjacent sampling points before and after it, forming a set of decision reference points with an odd total number. For each decision reference point, the signal receiving device can calculate the phase difference corresponding to that decision reference point and determine whether the phase difference is a positive or negative phase difference.

[0147] Subsequently, the signal receiving device counts the number of positive phase differences and the number of negative phase differences among multiple decision reference points. If the number of positive phase differences is greater than the number of negative phase differences, it indicates that most sampling points near the symbol decision sampling point exhibit a positive phase change direction, and the signal receiving device determines the symbol decision result corresponding to that symbol decision sampling point as the first value. If the number of negative phase differences is greater than the number of positive phase differences, it indicates that most sampling points near the symbol decision sampling point exhibit a negative phase change direction, and the signal receiving device determines the symbol decision result corresponding to that symbol decision sampling point as the second value. The signal receiving device performs the above statistical decision processing for each symbol decision sampling point to obtain the symbol decision result corresponding to each symbol decision sampling point.

[0148] In the above embodiments, by selecting multiple decision reference points with an odd total number centered on the symbol decision sampling point, and counting the number of positive and negative phase differences corresponding to the multiple decision reference points, symbol decision based on the majority phase change direction is realized, reducing the impact of phase difference of a single sampling point on the symbol decision result, and effectively improving the stability and accuracy of symbol decision of frequency shift keying signal under noise, sampling jitter or local phase disturbance scenarios.

[0149] In related technologies, after the frequency shift keying signal completes preamble synchronization, the frame start delimiter and the starting position of the subsequent physical layer header are usually calculated based solely on the preamble synchronization position and a fixed time interval or symbol interval. However, this method does not effectively correct for clock deviations, sampling offsets, and cumulative errors introduced by individual symbol misjudgments during the symbol decision process. Therefore, if there is a slight offset in the preamble synchronization result, the subsequently calculated frame boundary may shift, thus affecting the correct parsing of the physical layer header.

[0150] Based on this, in some embodiments, the method provided by the present invention further includes: writing the sequentially obtained symbol decision results into a decision window, the length of which is the same as the sequence length of the local frame start delimiter sequence; updating the symbol decision sequence in the decision window for each new symbol decision result, and matching the updated symbol decision sequence with the local frame start delimiter sequence; when the matching is successful, determining the symbol decision sampling point corresponding to the latest symbol decision result written into the decision window as the end position of the frame start delimiter, and determining the sampling position of the symbol after the end position as the start position of the physical layer header.

[0151] The decision window refers to a sliding window used to temporarily store the decision results of consecutive symbols, and its length is the same as the sequence length of the local frame start delimiter sequence. The local frame start delimiter sequence refers to the symbol sequence pre-stored by the signal receiving device, corresponding to the frame start delimiter specified in the communication protocol.

[0152] A symbol decision sequence refers to multiple symbol decision results arranged in the write sequence within the decision window; a successful match means that the symbol decision sequence within the decision window and the local frame start delimiter sequence meet a preset matching condition. In feasible implementations, the preset matching condition may be that the symbol decision sequence and the local frame start delimiter sequence are identical bit by bit. In other implementations, the preset matching condition may also be that the bit difference between the symbol decision sequence and the local frame start delimiter sequence does not exceed a preset threshold.

[0153] The end position of the frame start delimiter refers to the position of the last symbol in the local frame start delimiter sequence in the sampling point sequence when a match is successful; the start position of the physical layer header refers to the sampling position corresponding to the first symbol after the frame start delimiter.

[0154] The signal receiving device can pre-store the local frame start delimiter sequence and establish a decision window with the same length as the local frame start delimiter sequence. The signal receiving device obtains symbol decision results sequentially according to the timing of the symbol decision sampling points and writes the newly obtained symbol decision results into the decision window. While the decision window is not yet full, the signal receiving device continues to write subsequent symbol decision results; when the decision window is full, for each new symbol decision result obtained, the signal receiving device writes the new symbol decision result into the decision window and removes the earliest written symbol decision result from the decision window, thereby updating the symbol decision sequence within the decision window.

[0155] After each update of the decision window, the signal receiving device matches the current symbol decision sequence within the decision window with the local start-of-frame (FOB) delimiter sequence. If the match is successful, it indicates that the symbol decision sequence within the current decision window corresponds to the FOB delimiter in the received signal. At this point, the most recently written symbol decision result in the decision window corresponds to the last symbol in the local FOB delimiter sequence, and the signal receiving device determines the symbol decision sampling point corresponding to this most recently written symbol decision result as the end position of the FOB delimiter. Further, based on the sampling point interval corresponding to the symbol period, the signal receiving device offsets by one symbol after this end position to obtain the start position of the physical layer header. Thus, the signal receiving device can determine the starting sampling position of the physical layer header based on the actually determined FOB delimiter position.

[0156] In the above embodiments, sliding detection of the frame start delimiter is achieved by writing the symbol decision result into a decision window of the same length as the local frame start delimiter sequence, and updating the window and performing matching as new results are written. When a match is successful, the end position of the frame start delimiter is determined based on the symbol decision sampling point corresponding to the latest written result, and the start position of the physical layer header is further determined. This improves the accuracy of frame boundary positioning, reduces the risk of boundary offset, and enhances the reliability of subsequent frame parsing.

[0157] The wireless signal synchronization method in a power line carrier multimode communication system provided in this embodiment of the invention can be executed by a wireless signal receiving device. This embodiment of the invention uses the execution of the wireless signal synchronization method in a power line carrier multimode communication system by a wireless signal receiving device as an example to illustrate the wireless signal receiving device provided in this embodiment of the invention. Figure 4 This is a schematic diagram of the structure of a wireless signal receiving device provided in some embodiments of the present invention. For example... Figure 4 As shown, the wireless signal receiving device 400 includes an RF receiving circuit 401, a sampling circuit 402, and a processor 403.

[0158] RF receiving circuit 401 is used to receive frequency shift keying time domain signals; The sampling circuit 402 is connected to the radio frequency receiving circuit 401 and is used to sample the frequency shift keying time domain signal; The processor 403, connected to the sampling circuit 402, is used to execute the wireless signal synchronization method in the power line carrier multimode communication system described above.

[0159] According to the wireless signal receiving device provided in the embodiments of the present invention, by sampling the received frequency shift keying (FSK) time-domain signal to obtain a sampling point sequence, and making each symbol of the FFS time-domain signal correspond to a preset number of sampling points, a unified and stable data foundation can be provided for subsequent phase difference calculation and aggregation according to the repetition period, avoiding the impact of inconsistent sampling scales on synchronization judgment. On this basis, by determining the phase difference corresponding to each sampling point in the sampling point sequence, and according to the repetition period of the FFS preamble, the phase differences in the same period phase are signedly aggregated to form a periodic phase accumulation sequence. This allows phase differences that conform to the preamble repetition pattern to accumulate and enhance on the same period phase, while noise or interference that does not conform to the repetition pattern is difficult to form a stable accumulation, thereby improving the saliency of the preamble feature and enhancing the anti-noise and anti-interference capability of signal synchronization detection. Furthermore, the periodic phase accumulation sequence is further divided into a pre-spaced... The two phase summation values ​​are grouped together. The absolute values ​​of the two phase summation values ​​in each group are summed to obtain the peak intensity sequence. The signed average of the phase summation values ​​in the periodic phase summation sequence is then performed to obtain the waveform balance value. This allows for the simultaneous acquisition of the local peak intensity and the overall positive and negative balance of the preamble, improving the detection capability of the true preamble and suppressing false detections caused by non-target signals with only local peaks or significant overall bias. Finally, when the maximum value of the peak intensity sequence is greater than the first threshold and the absolute value of the waveform balance value is less than the second threshold, the synchronization position of the frequency shift keying preamble is determined based on the periodic phase corresponding to the maximum value. The synchronization result can be jointly constrained by the local peak intensity and the overall balance, making the determination of the synchronization position more accurate and reliable, thereby reducing the probability of false synchronization and improving the accuracy of frequency shift keying signal synchronization detection and the reliability of subsequent data demodulation.

[0160] In some embodiments, the processor is further configured to determine a periodic phase of twice the preset number based on the repetition period; for any periodic phase, accumulate the phase differences corresponding to each sampling point in the sampling point sequence that is in the corresponding periodic phase and the interval between two adjacent sampling points is twice the preset number, to obtain the phase accumulation value corresponding to the corresponding periodic phase; and combine the corresponding phase accumulation values ​​according to the arrangement order of each periodic phase in the repetition period to obtain the periodic phase accumulation sequence.

[0161] In some embodiments, the processor is further configured to, for any sampling point, determine a reference sampling point from the sampling point sequence that is separated from the corresponding sampling point by a phase measurement interval; perform conjugate multiplication on the complex sample value of the corresponding sampling point and the complex sample value of the reference sampling point; and determine the phase difference corresponding to the corresponding sampling point based on the conjugate multiplication result.

[0162] In some embodiments, the processor is further configured to determine a set of phase accumulation values ​​corresponding to the maximum value; determine the positive peak phase or negative peak phase of the frequency shift keying preamble according to the periodic phase corresponding to the corresponding set of phase accumulation values; and determine the sampling position corresponding to the positive peak phase or negative peak phase as the synchronization position.

[0163] In some embodiments, the processor is further configured to determine a plurality of symbol decision sampling points sequentially from the sampling point sequence based on the synchronization position; determine the symbol decision result corresponding to each symbol decision sampling point according to the positive or negative sign of the phase difference corresponding to each symbol decision sampling point; and obtain a symbol decision sequence according to the symbol decision result corresponding to the timing combination of each symbol decision sampling point.

[0164] In some embodiments, the processor is further configured to select a plurality of decision reference points of an odd number from the sampling point sequence, centered on any symbol decision sampling point; count the number of positive phase differences and negative phase differences in the phase differences corresponding to the plurality of decision reference points; when the number of positive phase differences is greater than the number of negative phase differences, determine the symbol decision result corresponding to the corresponding symbol decision sampling point as a first value; when the number of negative phase differences is greater than the number of positive phase differences, determine the symbol decision result corresponding to the corresponding symbol decision sampling point as a second value.

[0165] In some embodiments, the processor is further configured to write the sequentially obtained symbol decision results into a decision window, the length of which is the same as the sequence length of the local frame start delimiter sequence; for each new symbol decision result obtained, the symbol decision sequence in the decision window is updated, and the updated symbol decision sequence is matched with the local frame start delimiter sequence; when the match is successful, the symbol decision sampling point corresponding to the latest symbol decision result written into the decision window is determined as the end position of the frame start delimiter, and the sampling position of the symbol after the end position is determined as the start position of the physical layer header.

[0166] 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.

[0167] The wireless signal receiving device in this embodiment of the invention can be an electronic device or a component within an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other devices besides a terminal, such as a server.

[0168] The wireless signal receiving device provided in this embodiment of the invention can implement all the processes implemented in the above-described wireless signal receiving method embodiments. To avoid repetition, these processes will not be described again here.

[0169] In some embodiments, Figure 5 These are schematic diagrams of the structure of an electronic device provided in some embodiments of the present invention. For example... Figure 5 As shown, this embodiment of the invention also provides an electronic device 500, including a processor 501, a memory 502, and a computer program stored in the memory 502 and executable on the processor 501. When the program is executed by the processor 501, it implements the various processes of the wireless signal synchronization method embodiment in the above-described power line carrier multimode communication system and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0170] 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 wireless signal synchronization method embodiment in the above-described power line carrier multimode communication system and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0171] 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.

[0172] The computer-readable storage medium may include: read-only memory (ROM), random-access memory (RAM), magnetic disk or optical disk, etc.

[0173] This invention provides a computer program product, including a computer program that, when executed by a processor, implements the wireless signal synchronization method in the power line carrier multimode communication system described above.

[0174] 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 wireless signal synchronization method embodiment in the above-described power line carrier multimode communication system, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] 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 wireless signal synchronization in a power line carrier multimode communication system, characterized in that, include: The received frequency shift keying time-domain signal is sampled to obtain a sampling point sequence, wherein each symbol of the frequency shift keying time-domain signal corresponds to a preset number of sampling points; For any sampling point, a reference sampling point with a phase measurement interval separated from the corresponding sampling point is determined from the sampling point sequence; the phase measurement interval is the ratio of the preset number to the scaling factor, and the scaling factor is determined based on the modulation index of the frequency shift keying time domain signal; Perform conjugate multiplication on the complex sampled value of the corresponding sampling point and the complex sampled value of the reference sampling point, and determine the phase difference corresponding to the corresponding sampling point based on the conjugate multiplication result; According to the repetition period of the frequency shift keying preamble, a periodic phase twice the preset number is determined; the frequency shift keying preamble includes two alternating preamble symbols, and the repetition period corresponds to two preamble symbols; For any periodic phase, the phase difference of each sampling point in the sampling point sequence that is in the corresponding periodic phase and the interval between two adjacent sampling points is twice the preset number is accumulated to obtain the phase accumulation value corresponding to the corresponding periodic phase. By combining the corresponding phase accumulation values ​​according to the arrangement order of each periodic phase in the repeating period, a periodic phase accumulation sequence is obtained. The two phase accumulation values ​​that are separated by the preset number in the periodic phase accumulation sequence are divided into a group. The absolute values ​​of the two phase accumulation values ​​in each group are summed to obtain the peak intensity sequence. The signed average of each phase accumulation value in the periodic phase accumulation sequence is then performed to obtain the waveform balance value. When the maximum value of the peak intensity sequence is greater than the first threshold and the absolute value of the waveform balance value is less than the second threshold, the synchronization position of the frequency shift keying preamble is determined according to the periodic phase corresponding to the maximum value.

2. The wireless signal synchronization method in a power line carrier multimode communication system according to claim 1, characterized in that, The second threshold is less than the first threshold; the preset number is 16, and the frequency shift keying preamble includes preamble symbols arranged alternately with 0 and 1.

3. The wireless signal synchronization method in a power line carrier multimode communication system according to claim 1, characterized in that, Determining the synchronization position of the frequency shift keying preamble based on the periodic phase corresponding to the maximum value includes: Determine a set of phase accumulation values ​​corresponding to the maximum value; Based on the periodic phase corresponding to the phase accumulation value of each group, the positive peak phase or negative peak phase of the frequency shift keying preamble is determined. The sampling position corresponding to the positive peak phase or the negative peak phase is determined as the synchronization position.

4. The wireless signal synchronization method in a power line carrier multimode communication system according to claim 1, characterized in that, The method further includes: Based on the synchronization position, multiple symbol decision sampling points are sequentially determined from the sampling point sequence according to the preset number; Based on the sign of the phase difference corresponding to each symbol decision sampling point, the symbol decision result corresponding to each symbol decision sampling point is determined respectively; The symbol decision sequence is obtained by combining the symbol decision sampling points according to their temporal combinations.

5. The wireless signal synchronization method in a power line carrier multimode communication system according to claim 4, characterized in that, The step of determining the symbol decision result corresponding to each symbol decision sampling point based on the positive or negative sign of the phase difference corresponding to each symbol decision sampling point includes: Centered on any symbol decision sampling point, select multiple decision reference points from the sampling point sequence, with an odd total number; Count the number of positive and negative phase differences among the phase differences corresponding to the multiple decision reference points; When the number of positive phase differences is greater than the number of negative phase differences, the symbol decision result corresponding to the corresponding symbol decision sampling point is determined as the first value; When the number of negative phase differences is greater than the number of positive phase differences, the symbol decision result corresponding to the corresponding symbol decision sampling point is determined as the second value.

6. The wireless signal synchronization method in a power line carrier multimode communication system according to claim 4 or 5, characterized in that, The method further includes: The symbol decision results obtained sequentially are written into the decision window, the length of which is the same as the sequence length of the local frame start delimiter sequence; For each new symbol decision result obtained, the symbol decision sequence in the decision window is updated, and the updated symbol decision sequence is matched with the local frame start delimiter sequence; When a match is successful, the symbol decision sampling point corresponding to the latest symbol decision result written into the decision window is determined as the end position of the frame start delimiter, and the sampling position of the symbol one symbol after the end position is determined as the start position of the physical layer header.

7. A wireless signal receiving device, applied to a power line carrier multimode communication system, characterized in that, include: Radio frequency receiving circuit, used to receive frequency shift keying time domain signals; A sampling circuit, connected to the radio frequency receiving circuit, is used to sample the frequency shift keying time domain signal; A processor, connected to the sampling circuit, is used to execute the wireless signal synchronization method in a power line carrier multimode communication system as described in any one of claims 1 to 6.

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