Method for power line carrier signal multi-band synchronization

Abstract

The application discloses a power line carrier signal multi-frequency band synchronization method, and belongs to the technical field of communication. The power line carrier signal multi-frequency band synchronization method comprises the following steps: performing synchronization calculation on a received signal under a plurality of preset communication frequency bands to obtain synchronization calculation results corresponding to the communication frequency bands; when the synchronization calculation result of a first communication frequency band meets a starting synchronization condition, determining a first peak value parameter of the first communication frequency band, and updating the first peak value parameter according to a new correlation peak; continuing to perform synchronization calculation on the received signal under the preset communication frequency bands; if the synchronization calculation result of a second communication frequency band meets the starting synchronization condition, and a second peak value parameter of the second communication frequency band meets a preset comparison condition with the first peak value parameter obtained through the last update, the target synchronization position of the received signal is determined under the second communication frequency band. The application significantly improves the signal synchronization accuracy in a low signal-to-noise ratio and frequency band overlapping scene.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, and in particular relates to a method for multi-band synchronization of power line carrier signals. Background Technology

[0002] With the development of power line carrier communication technology, multi-band communication technology has been gradually applied to high-speed power line communication systems. This technology allows different nodes in the same communication network to dynamically select different communication frequency bands based on channel conditions, thereby improving spectrum utilization and network flexibility. However, in this application scenario, the signal receiver needs to have the ability to detect signals in multiple frequency bands and accurately identify the frequency band to which the received signal belongs.

[0003] In related technologies, the signal synchronization method for power line carrier communication is usually based on a single-band design, that is, the receiver only performs synchronization calculations on a preset frequency band and determines the synchronization position through methods such as cross-correlation, autocorrelation and continuous correlation peak detection.

[0004] However, when the signal receiver performs synchronization calculations for multiple frequency bands simultaneously, each band will generate its own correlation peak due to the different synchronization sequences of the different frequency bands. The first detected correlation peak may not correspond to the actual transmission frequency band, especially in cases of low signal-to-noise ratio or frequency overlap. The characteristic differences between signals of different frequency bands become blurred, leading to missynchronization. This, in turn, affects the communication reliability of the high-speed power line communication system. Summary of the Invention

[0005] This invention aims to address at least one of the technical problems existing in the prior art. To this end, this invention proposes a multi-band synchronization method for power line carrier signals, which can effectively identify missynchronization states in multi-band communication, thereby significantly improving the signal synchronization accuracy in scenarios with low signal-to-noise ratios and overlapping frequency bands.

[0006] In a first aspect, the present invention provides a method for multi-band synchronization of power line carrier signals, the method comprising: Synchronization calculations are performed on the received signals under multiple preset communication frequency bands to obtain the synchronization calculation results corresponding to each communication frequency band; When the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, the first peak parameter of the first communication frequency band is determined, and when a new correlation peak is detected subsequently, the first peak parameter is updated according to the new correlation peak. Continue to perform synchronous calculations on the received signals under each preset communication frequency band; If the synchronization calculation result of the second communication frequency band meets the initial synchronization condition, and the second peak parameter of the second communication frequency band meets the preset comparison condition with the first peak parameter obtained in the most recent update, the target synchronization position of the received signal is determined in the second communication frequency band.

[0007] According to one embodiment of the present invention, the second peak parameter of the second communication frequency band and the first peak parameter obtained in the most recent update satisfy a preset comparison condition, including: the second peak parameter is greater than or equal to the product of the first peak parameter obtained in the most recent update and a preset overlap coefficient; wherein the preset overlap coefficient is greater than 1.

[0008] According to one embodiment of the present invention, when the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, the gain control coefficient is locked; if the synchronization calculation result of the second communication frequency band meets the initial synchronization condition, and the second peak parameter of the second communication frequency band meets the preset comparison condition with the first peak parameter obtained in the most recent update, the lock on the gain control coefficient is released; the gain control coefficient is adjusted based on the signal energy of the second communication frequency band, and the adjusted gain control coefficient is locked.

[0009] According to one embodiment of the present invention, adjusting the gain control coefficient based on the signal energy of a second communication frequency band specifically includes: determining multiple signal sampling points within a preset symbol period in the second communication frequency band; and adjusting the gain control coefficient according to the comparison result between the signal energy of each sampling point and the target energy range.

[0010] According to one embodiment of the present invention, a plurality of preset communication frequency bands include a main frequency band and a sub-frequency band, wherein the frequency range of the sub-frequency band partially overlaps with the frequency range of the main frequency band; wherein, the first communication frequency band is one of the main frequency band and the sub-frequency band, and the second communication frequency band is the other.

[0011] According to one embodiment of the present invention, when the frequency ranges of the sub-band and the main band partially overlap, the main band and the sub-band are respectively used to perform synchronization calculations using synchronization sequences generated based on different phase rotation factors.

[0012] According to one embodiment of the present invention, when the synchronization calculation results of other communication frequency bands besides the first communication frequency band do not meet the initial synchronization condition, the received signal is synchronized based on the synchronization calculation results of the first communication frequency band.

[0013] According to one embodiment of the present invention, when a correlation peak is detected in any communication frequency band, channel estimation is performed on the received signal to obtain a channel estimation result; the channel estimation result is used to perform channel equalization on the received signal.

[0014] According to one embodiment of the present invention, when the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, the first peak parameter of the first communication frequency band is determined, specifically including: determining that the initial synchronization condition is met when a continuous correlation peak is detected based on the synchronization calculation result of the first communication frequency band; and determining the first peak parameter based on the average value of the peak values ​​of the continuous correlation peaks.

[0015] According to one embodiment of the present invention, determining the detection of continuous correlation peaks based on the synchronization calculation results under the first communication frequency band specifically includes: performing synchronization calculation on the received signal under the first communication frequency band to detect correlation peaks; counting the continuously detected correlation peaks, and determining that the synchronization calculation results under the first communication frequency band indicate the detection of continuous correlation peaks when the count value exceeds a preset number threshold.

[0016] In a second aspect, the present invention provides a multi-band synchronization device for power line carrier signals, the device comprising: The first synchronization module is used to perform synchronization calculations on the received signals under multiple preset communication frequency bands to obtain the synchronization calculation results corresponding to each communication frequency band. The detection module is used to determine the first peak parameter of the first communication frequency band when the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, and to update the first peak parameter according to the new correlation peak when a new correlation peak is detected in the future. The second synchronization module is used to continue to perform synchronization calculations on the received signals under each preset communication frequency band; The determination module is used to determine the target synchronization position of the received signal in the second communication frequency band if the synchronization calculation result of the second communication frequency band meets the initial synchronization condition and the second peak parameter of the second communication frequency band meets the preset comparison condition with the first peak parameter obtained in the most recent update.

[0017] Thirdly, the present invention provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the power line carrier signal multi-band synchronization method as described in the first aspect above.

[0018] Fourthly, the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the power line carrier signal multi-band synchronization method as described in the first aspect above.

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

[0020] In a sixth aspect, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the power line carrier signal multi-band synchronization method as described in the first aspect above.

[0021] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: By performing parallel synchronization calculations on received signals across multiple preset communication frequency bands, the synchronization results of each band can be mutually verified. This avoids the missed detection problem caused by only detecting a single frequency band, which is unpredictable in multi-band networks where the receiver cannot know the actual frequency band of the transmitter. This provides a data foundation for subsequent frequency band selection. When the first communication frequency band meets the initial synchronization conditions, a first peak parameter is determined, and this parameter is continuously updated when new related peaks are detected. This ensures that the first peak parameter reflects the latest signal condition under the current channel conditions, avoiding reference deviations caused by transient noise or fading of early peaks. Under this dynamic reference, the remaining frequency bands are continued to be detected. If the second communication frequency band... If the initial synchronization condition is met and the second peak parameter meets the preset comparison condition with the first peak parameter obtained in the most recent update, then the system switches to the second communication frequency band for synchronization. This allows the system to identify and correct the false correlation peak that appears first in a communication frequency band when the frequency band overlaps or the signal-to-noise ratio is low. At the same time, since the first peak parameter is dynamically updated as the comparison benchmark, it can adapt to the time-varying characteristics of the channel and avoid misjudgment or omission caused by a fixed benchmark. This significantly reduces the false synchronization rate and shortens the recovery time. Finally, the target synchronization position is determined based on the correct second communication frequency band, thereby improving the signal synchronization accuracy in low signal-to-noise ratio and frequency band overlap scenarios.

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

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a multi-band power line communication network architecture provided in some embodiments of the present invention; Figure 2 This is a flowchart illustrating a multi-band synchronization method for power line carrier signals provided in some embodiments of the present invention; Figure 3 This is a schematic diagram of the gain control and signal processing link in a signal receiving device provided in some embodiments of the present invention; Figure 4 This is a flowchart illustrating the multi-band synchronization calculation provided in some embodiments of the present invention; Figure 5 This is a schematic diagram of the overall process of the multi-band synchronization method provided in some embodiments of the present invention; Figure 6 This is a schematic diagram of the structure of a power line carrier signal multi-band synchronization device provided in some embodiments of the present invention; Figure 7This is a schematic diagram of the structure of an electronic device provided in some embodiments of the present invention. Detailed Implementation

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

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

[0026] In power line communication systems, traditional communication networks typically employ a single-band communication mechanism, where all nodes use the same frequency band for data transmission. With the introduction of multi-band communication technology, different nodes can use different communication bands at the same time, improving network flexibility and spectrum utilization. However, this places demands on the signal receiver's multi-band detection capabilities. For example, when two frequency bands exist, the signal receiver needs to perform synchronization calculations for both bands separately, and then locate the synchronization position and determine the communication band to which the signal belongs based on the resulting signal correlation peaks.

[0027] However, in practical applications, especially in low signal-to-noise ratio environments, signals are severely interfered with by noise, resulting in weak effective signal components. This significantly reduces the accuracy and reliability of signal correlation peaks during synchronization calculations. Furthermore, when different communication frequency bands overlap, the differences in signal characteristics between the bands become blurred, easily causing confusion at the signal receiver when determining signal synchronization, leading to missynchronization. Once missynchronization occurs, subsequent signal demodulation will be severely affected, reducing the accuracy and reliability of data transmission.

[0028] In view of this, embodiments of the present invention provide a multi-band synchronization method for power line carrier signals, which aims to solve the problem of signal missynchronization that easily occurs in scenarios with multiple frequency bands, low signal-to-noise ratio, and overlapping frequency bands. By establishing a benchmark based on the frequency band that first meets the conditions under multiple preset communication frequency bands, and using the correlation peak-to-peak value of subsequent frequency bands to identify missynchronization and switch to the correct frequency band to relock, false synchronization is automatically corrected and the signal synchronization accuracy is improved.

[0029] The multi-band synchronization method for power line carrier signals provided by the present invention will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0030] Figure 1 This is a schematic diagram of a multi-band power line communication network architecture provided in some embodiments of the present invention. For example... Figure 1 As shown, the multi-band power line communication network includes a Central Coordinator (CCO), three Proxy Coordinators (PCOs), namely PCO1, PCO2, and PCO3, and eight Stations (STAs), namely STA1, STA2, STA3, STA4, STA5, STA6, STA7, and STA8. The CCO is connected to each PCO and STA via power lines, forming a hierarchical network topology. In this network, different nodes can use different communication frequency bands for data transmission. Figure 1 Frequency band A, represented by a black straight line, and frequency band B, represented by a black dashed line, are two preset communication frequency bands. CCO, PCO1, STA1, and STA2 use frequency band A; PCO2, PCO3, STA3, STA4, STA5, STA6, STA7, and STA8 use frequency band B. Frequency bands A and B may have partial frequency overlap or be completely separate. This multi-band parallel communication mechanism improves spectrum utilization and network flexibility, but it also requires the signal receiver to have multi-band synchronization detection capabilities. That is, after receiving a signal, synchronization calculations must be performed separately for frequency bands A and B to accurately identify the frequency band to which the received signal belongs and determine the signal's synchronization position.

[0031] The multi-band synchronization method for power line carrier signals provided by this invention can be applied to a power line communication system including a signal transmitting device and a signal receiving device. The signal transmitting device is used to transmit signals, and the signal receiving device enters a signal synchronization state after receiving the signal from the signal transmitting device, so as to extract key data from the subsequent signal.

[0032] Furthermore, the signal transmitting and receiving devices can be, for example, electronic devices, such as power line communication terminals, concentrator devices, smart meters, communication module embedded devices, or communication test terminals. Alternatively, the electronic devices can also be devices with computing capabilities or intelligent robots to perform the signal acquisition, processing, and synchronization steps in this invention.

[0033] The present invention provides a multi-band synchronization method for power line carrier signals. The subject executing the method can be a signal receiving device, or a functional module or functional entity in the signal receiving device that can implement the method.

[0034] The following description uses a signal receiving device as an example to illustrate the multi-band synchronization method for power line carrier signals provided in this embodiment of the invention.

[0035] Figure 2 This is a flowchart illustrating a multi-band synchronization method for power line carrier signals provided in some embodiments of the present invention. For example... Figure 2 As shown, the multi-band synchronization method for power line carrier signals includes steps 210 to 240.

[0036] Step 210: Perform synchronization calculations on the received signals under multiple preset communication frequency bands to obtain the synchronization calculation results corresponding to each communication frequency band.

[0037] Here, the preset communication frequency band refers to multiple different frequency ranges pre-configured by the signal receiving device for performing synchronization detection respectively. In some embodiments, the multiple preset communication frequency bands include a main frequency band and at least one sub-frequency band, and the frequency range of the sub-frequency band partially overlaps with the frequency range of the main frequency band, that is, the passband of the sub-frequency band and the passband of the main frequency band have an overlapping area on the frequency axis, and their center frequencies are different.

[0038] Synchronization calculation refers to the process by which a signal receiving device performs correlation operations between a local synchronization sequence and the received signal to detect synchronization features in the received signal. For example, synchronization calculation includes, but is not limited to, cross-correlation and autocorrelation operations. During synchronization calculation, for each preset communication frequency band, the signal receiving device first performs sliding cross-correlation processing on the local synchronization sequence corresponding to that frequency band and the received signal sequence to obtain a cross-correlation result sequence. Then, utilizing the periodicity of the synchronization sequence, autocorrelation processing is performed on the cross-correlation result sequence (for example, multiplying the cross-correlation value of the current sampling point by the conjugate of historical cross-correlation values ​​delayed by one Orthogonal Frequency Division Multiplexing (OFDM) symbol length and accumulating the results), to suppress non-periodic noise and interference and enhance the prominence of the true synchronization peak.

[0039] In some embodiments, the synchronization calculation results include, but are not limited to, one or more of the following: cross-correlation value sequence, autocorrelation value sequence, peak amplitude of detected correlation peaks, peak position, count of consecutive correlation peaks, and determination flags indicating whether the initial synchronization conditions are met.

[0040] After synchronization is initiated, the signal receiving device performs the aforementioned synchronization calculations on multiple preset communication frequency bands. In some embodiments, the synchronization calculations for multiple frequency bands can be performed in parallel, that is, the signal receiving device maintains multiple synchronization calculation channels simultaneously, each corresponding to a preset communication frequency band. Each channel independently performs sliding cross-correlation and autocorrelation calculations and updates its own synchronization calculation results in real time.

[0041] In other embodiments, when hardware resources are limited, a time-sharing processing method can also be adopted, in which the signal receiving device performs synchronous calculations on each frequency band in a preset time order and saves the key intermediate results of each frequency band.

[0042] It should be noted that, regardless of the method used, the signal receiving device ultimately obtains synchronization calculation results corresponding to each communication frequency band, which are used for subsequent determination of initial synchronization conditions and cross-validation. Through multi-band parallel or time-division synchronization calculation, the signal receiving device can simultaneously monitor the occurrence of synchronization signals in different frequency dimensions, providing multi-source and multi-dimensional decision-making basis for subsequent multi-band cross-validation and missynchronization detection.

[0043] Step 220: When the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, determine the first peak parameter of the first communication frequency band, and update the first peak parameter according to the new correlation peak when a new correlation peak is detected in the future.

[0044] The first communication frequency band refers to the communication frequency band whose synchronization calculation result first meets the initial synchronization condition among multiple preset communication frequency bands. Specifically, the signal receiving device performs synchronization calculation in parallel or in time-division multiple preset communication frequency bands (e.g., a main frequency band and at least one sub-frequency band). When the synchronization calculation result of a certain frequency band first reaches the initial synchronization condition (e.g., a preset number of valid correlation peaks are continuously detected), that frequency band is determined as the first communication frequency band.

[0045] The initial synchronization condition refers to the decision rule used to determine whether a valid synchronization signal start position has been detected in the current communication frequency band.

[0046] In some embodiments, the initial synchronization condition may be, for example, the continuous detection of a preset threshold of correlation peaks within a certain communication frequency band. Specifically, the signal receiving device performs synchronization calculations on the received signal within this frequency band. Whenever a valid correlation peak is detected (e.g., the cross-correlation or autocorrelation result exceeds a dynamic threshold and passes validity verification), the continuously detected correlation peaks are counted. When the count value is greater than or equal to the preset threshold, the signal receiving device determines that the synchronization calculation result within this frequency band meets the initial synchronization condition. The detection of continuous correlation peaks utilizes the periodic repetition characteristic of the synchronization sequence, effectively eliminating spurious peaks caused by isolated noise or sudden interference, thus improving the reliability of the initial synchronization determination.

[0047] In other embodiments, the initial synchronization condition may be, for example, detecting that the peak amplitude of a single correlation peak exceeds a preset high energy threshold in a certain communication frequency band, and that the ratio of the peak value to the average noise floor within a preset time window before and after is greater than a preset signal-to-noise ratio threshold.

[0048] In some other embodiments, the initial synchronization condition may be, for example, that the peak position of the detected autocorrelation result remains stable over multiple consecutive OFDM symbol periods in a certain communication frequency band, or that the cross-correlation result and the autocorrelation result simultaneously satisfy their respective preset thresholds in a certain communication frequency band, or one or more of the following:

[0049] The first peak parameter refers to a quantitative indicator used to characterize the strength of the synchronization signal in the first communication frequency band. For example, the first peak parameter may be the average peak value, the maximum peak value, the median peak value, or the sum of peak energies corresponding to consecutive correlated peaks.

[0050] The signal receiving device performs synchronization calculations in parallel or in a time-division manner across multiple preset communication frequency bands. When the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, the signal receiving device first determines the first peak parameter of the first communication frequency band. For example, if the initial synchronization condition is based on continuous correlation peak detection (e.g., continuous detection of correlation peaks of a preset number threshold), the signal receiving device can use the average peak value of the consecutive correlation peaks as the initial value of the first peak parameter; if the initial synchronization condition is based on a single valid correlation peak, the peak value of that correlation peak can be used as the initial value of the first peak parameter.

[0051] Following this, the signal receiving device continues to perform synchronous calculations on the first communication frequency band to detect any new correlation peaks that subsequently appear. Whenever a new valid correlation peak is detected, the signal receiving device updates the current first peak parameter based on the peak value of the new correlation peak. The update method can be varied, for example, using a moving average method, weighting the new peak value with historical peak values; or using a maximum value hold method, replacing the current first peak parameter if the new peak value is greater than it, otherwise leaving it unchanged; or using an exponentially weighted moving average (EWMA) method, which smoothly follows changes in signal strength.

[0052] Through this mechanism, the first peak parameter can reflect the strength of the latest detected synchronization signal on the first communication frequency band in real time, avoiding the reference deviation caused by the influence of instantaneous noise, fading or sudden interference on the early detected peak, and providing a more accurate and real-time comparison benchmark for subsequent cross-validation with the second communication frequency band.

[0053] It should be noted that the above update process runs through the entire synchronization detection phase. That is, after the first communication frequency band meets the initial synchronization conditions, regardless of the detection results of other frequency bands, the signal receiving device continuously monitors the first communication frequency band and updates the first peak parameter, so that the first peak parameter can adaptively track the changes in channel conditions, thereby improving the robustness and accuracy of the multi-band synchronization method in time-varying channel environments.

[0054] Step 230: Continue to perform synchronous calculations on the received signals under each preset communication frequency band.

[0055] After completing the initial synchronization determination of the first communication frequency band and the initialization and update of the first peak parameter in step 220, the signal receiving device does not stop the synchronization monitoring of other communication frequency bands or the current communication frequency band, but continues to perform synchronization calculations on the received signal in all preset communication frequency bands (including the first communication frequency band, the second communication frequency band and other preset frequency bands).

[0056] For each preset communication frequency band, the signal receiving device uses its corresponding local synchronization sequence to perform sliding cross-correlation and autocorrelation calculations with the received signal, updating the synchronization calculation results of each communication frequency band in real time. In some implementations, the synchronization calculation process can be performed in parallel with the peak parameter update process on the first communication frequency band, or it can be completed sequentially in a time-division processing mode.

[0057] It should be noted that the signal receiving device continues to perform synchronization calculations on the first communication frequency band to detect new correlation peaks and update the first peak value parameter, while simultaneously continuing to perform synchronization calculations on the remaining communication frequency bands (such as the second communication frequency band) to monitor whether these frequency bands meet the initial synchronization conditions.

[0058] By continuously performing synchronization calculations in each preset communication frequency band, the signal receiving device can obtain the latest synchronization status of all frequency bands in real time, providing timely and accurate data support for subsequent steps to determine whether there is a second communication frequency band that meets the initial synchronization conditions and to compare peak parameters.

[0059] Step 240: If the synchronization calculation result of the second communication frequency band satisfies the initial synchronization condition, and the second peak parameter of the second communication frequency band satisfies the preset comparison condition with the first peak parameter obtained in the most recent update, determine the target synchronization position of the received signal in the second communication frequency band.

[0060] The second communication frequency band refers to one of the multiple preset communication frequency bands, excluding the first communication frequency band, whose synchronization calculation result satisfies the initial synchronization condition. It should be noted that the second communication frequency band does not specifically refer to a fixed frequency band, but rather refers to other frequency bands that reach the initial synchronization condition later than the first communication frequency band in time sequence.

[0061] In cases where multiple other communication frequency bands simultaneously or sequentially meet the initial synchronization conditions, in some implementations, the signal receiving device can select one of them as the second communication frequency band for cross-verification according to a preset priority (e.g., priority of the main frequency band or priority of the frequency band with the larger peak parameter). Alternatively, it can compare it sequentially with the first peak parameter obtained in the most recent update. As long as any second communication frequency band that meets the conditions exists, the frequency band switching is triggered.

[0062] The second peak parameter refers to a quantitative indicator used to characterize the strength of the synchronization signal in the second communication frequency band, and its definition corresponds to that of the first peak parameter. For example, the second peak parameter can be characterized in the same way as the first peak parameter, such as the average peak value, maximum peak value, median peak value, peak energy, or average peak value to noise floor ratio of consecutive correlated peaks. To ensure comparability between the first and second peak parameters, the signal receiving device uses the same parameter type when calculating both (e.g., if the first peak parameter uses the average peak value, then the second peak parameter also uses the average peak value).

[0063] The most recently updated first peak parameter refers to the latest value of the first peak parameter obtained after the signal receiving device continuously performs synchronization calculations on the first communication frequency band in steps 220 and 230 and updates it continuously when a new correlation peak is detected. This value reflects the latest synchronization signal strength level on the first communication frequency band up to the current moment, rather than just the static value at the initial detection.

[0064] The preset comparison condition refers to the criterion used to determine whether the synchronization signal strength of the second communication frequency band is sufficient to "cover" or "deny" the synchronization result of the first communication frequency band. In some embodiments, the preset comparison condition includes a second peak parameter being greater than or equal to the product of the most recently updated first peak parameter and a preset overlap coefficient. This ensures that when the signal strength of the second communication frequency band is significantly higher than the latest signal strength of the first communication frequency band, the system switches to the second communication frequency band, thereby avoiding frequent switching due to minor fluctuations.

[0065] The target synchronization position refers to the precise sampling point position in the received signal used to mark the start of a data frame or the boundary of an OFDM symbol, including but not limited to one or more of the following: frame start position, symbol start position, the start position of a Fast Fourier Transform (FFT) window, or the end position of a specific synchronization sequence.

[0066] In some embodiments, the signal receiving device continuously performs synchronization calculations on each preset communication frequency band. When the synchronization calculation result of the second communication frequency band meets the initial synchronization condition, the signal receiving device acquires the second peak parameter of that frequency band and reads the first peak parameter most recently updated on the first communication frequency band. Subsequently, the signal receiving device compares the second peak parameter with the first peak parameter according to preset comparison conditions. If the preset comparison conditions are met, the synchronization result of the first communication frequency band is determined to be a missynchronization, and the synchronization operating frequency band is switched to the second communication frequency band.

[0067] In this scenario, the signal receiving device no longer uses the first communication frequency band as the synchronization basis. Instead, it determines the target synchronization position of the received signal based on the synchronization calculation results of the second communication frequency band. In other words, the signal receiving device continues to perform synchronization calculations in the second communication frequency band, detects subsequent correlation peaks (especially negative correlation peaks), and calculates the target synchronization position based on the position of the negative correlation peaks and the offset predefined by the communication protocol. This target synchronization position will be used for subsequent data demodulation, channel estimation, and frequency offset compensation.

[0068] Among them, false synchronization refers to the fact that the synchronization position determined by the signal receiving device based on the first communication frequency band is not the real signal start position, but a false synchronization caused by factors such as interference, noise or energy leakage between frequency bands.

[0069] In some embodiments, the signal receiving device performs sliding cross-correlation and autocorrelation operations with the received signal using the local synchronization sequence corresponding to the second communication frequency band, and monitors the occurrence of correlation peaks in real time. Since the second communication frequency band has been verified as a reliable synchronization band (its peak parameters meet preset comparison conditions), the detected correlation peaks have high authenticity and stability. During the detection of subsequent correlation peaks, the signal receiving device determines the signal synchronization position by detecting the position of the negative correlation peaks.

[0070] A negative correlation peak refers to a peak with a negative correlation value and a large absolute value in the results of cross-correlation or autocorrelation calculations. In typical power line carrier communication systems, synchronization sequences are usually composed of alternating positive and negative symbols, such as SYNCP (Synchronization Pattern) followed by SYNCM (Synchronization Marker). SYNCM and SYNCP have opposite polarities, so the correlation peak corresponding to SYNCM exhibits a negative value during cross-correlation or autocorrelation processing. When a negative correlation peak is detected, its position often corresponds to the boundary of signal frame synchronization or the end position of a specific synchronization sequence, thus determining the target synchronization position.

[0071] In some embodiments, when the signal receiving device detects a negative correlation peak in the second communication frequency band, it records the sampling point index corresponding to the negative correlation peak. Then, based on a predefined offset in the communication protocol (e.g., a fixed sampling point interval between the position of the negative correlation peak and the start position of the data frame), the sampling point index is offset to obtain the final target synchronization position. For example, if the negative correlation peak corresponds to the end position of SYNCM, and the protocol specifies that the Mth sampling point after the end of SYNCM is the start position of the first data symbol, then the target synchronization position is the position of the negative correlation peak plus the offset M.

[0072] In other embodiments, to improve the accuracy of the synchronization position determination, the signal receiving device can further perform weighted averaging or interpolation calculations by combining the positions of multiple consecutive correlation peaks after detecting a negative correlation peak. For example, the signal receiving device records the positions of several consecutively detected positive and negative correlation peaks, and uses the fixed interval relationship between these positions and the frame structure to obtain a more accurate target synchronization position through calculation methods such as least squares fitting or moving average filtering.

[0073] The multi-band synchronization method for power line carrier signals provided by the present invention performs synchronization calculations on the received signals in parallel under multiple preset communication frequency bands, enabling the synchronization results of each frequency band to verify each other. This avoids the missed detection problem caused by only detecting a single frequency band, which leads to the signal receiver not being able to predict the actual frequency band of the signal transmitter in a multi-band network. This provides a data foundation for subsequent frequency band selection. When the first communication frequency band meets the initial synchronization conditions, a first peak parameter is determined, and this parameter is continuously updated when a new correlation peak is detected. This ensures that the first peak parameter reflects the latest signal condition under the current channel conditions, avoiding reference deviation caused by the influence of instantaneous noise or fading on early peaks. The method continues to detect signals under this dynamic reference. If the second communication frequency band also meets the initial synchronization conditions and its second peak parameter meets the preset comparison conditions with the first peak parameter obtained in the most recent update, then the synchronization is switched to the second communication frequency band. This allows the real frequency band with a higher peak value to identify and correct the false correlation peak that appears first in a communication frequency band under conditions of frequency band overlap or low signal-to-noise ratio. At the same time, since the first peak parameter is dynamically updated as the comparison benchmark, it can adapt to the time-varying characteristics of the channel and avoid misjudgment or omission caused by a fixed benchmark. This significantly reduces the false synchronization rate and shortens the recovery time. Finally, the target synchronization position is determined based on the correct second communication frequency band, thereby improving the signal synchronization accuracy in low signal-to-noise ratio and frequency band overlap scenarios.

[0074] In some embodiments, the second peak parameter of the second communication frequency band and the first peak parameter obtained in the most recent update satisfy a preset comparison condition, specifically including: the second peak parameter is greater than or equal to the product of the first peak parameter obtained in the most recent update and a preset overlap coefficient, wherein the preset overlap coefficient is greater than 1.

[0075] The preset overlap coefficient refers to a proportional factor pre-configured within the signal receiving device to adjust the stringency of the comparison between the second peak parameter and the first peak parameter. A preset overlap coefficient greater than 1 enables the signal receiving device to better detect the difference between the correlation peaks of the first and second communication frequency bands.

[0076] In some embodiments, the preset overlap coefficient may be related to the degree of frequency overlap between the first and second communication frequency bands. The degree of frequency overlap refers to the relative proportion of the width of the overlapping portion of the two communication frequency bands in the spectrum to the width of their respective bands. For example, when the two frequency bands completely overlap, the overlap is 100%; when the two frequency bands partially overlap, the overlap is between 0% and 100%; and when the two frequency bands do not overlap at all, the overlap is 0%. Exemplarily, the smaller the frequency overlap, the larger the preset overlap coefficient, and the two are negatively correlated. This is because the higher the frequency overlap, the greater the proportion of signal energy leakage from one frequency band to the other. In this case, the peak parameter of the second communication frequency band due to leakage may be very close to the true peak value of the first communication frequency band. To correctly identify the true synchronization frequency band even in scenarios with severe leakage, a smaller preset overlap coefficient (e.g., 1.1 or 1.2) needs to be set so that the second peak parameter only needs to be slightly larger than the first peak parameter (e.g., 1.1 times) to trigger a missynchronization determination, thereby avoiding the erroneous suppression of the true synchronization signal due to leakage. Conversely, the lower the frequency overlap, the less energy leakage. If a real synchronization signal exists in the second communication band, its peak value should be significantly higher than the leakage peak value of the first communication band. In this case, a larger preset overlap coefficient (e.g., 1.5 or 2.0) can be used, requiring the second peak parameter to be significantly higher than the first peak parameter by a certain multiple before triggering a missynchronization judgment, thereby reducing the risk of misjudgment caused by noise or slight interference.

[0077] The signal receiving device calculates the product of the first peak parameter Peak1 and the preset overlap coefficient a to obtain the comparison threshold Peak1*a. Then, the second peak parameter Peak2 is compared with the comparison threshold. If Peak2 ≥ Peak1*a, it is determined that the second peak parameter of the second communication frequency band and the first peak parameter meet the preset comparison condition; otherwise, they do not meet the condition.

[0078] In the above embodiments, by requiring the second peak parameter to reach a relatively high proportion of the first peak parameter before triggering the judgment, the probability of misjudging false synchronization as true synchronization due to noise or random interference can be effectively reduced. This adaptive comparison strategy reduces both the probability of misjudging false synchronization caused by energy leakage as true synchronization and the probability of missing true synchronization due to leakage peak interference, significantly improving the synchronization reliability and judgment accuracy of the power line carrier communication system in multi-band overlapping environments.

[0079] In some embodiments, when the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, the gain control coefficient is locked; if the synchronization calculation result of the second communication frequency band meets the initial synchronization condition, and the second peak parameter of the second communication frequency band meets the preset comparison condition with the first peak parameter obtained in the most recent update, the lock on the gain control coefficient is released; the gain control coefficient is adjusted based on the signal energy of the second communication frequency band, and the adjusted gain control coefficient is locked.

[0080] The Automatic Gain Control (AGC) coefficient refers to the control parameter used in signal receiving equipment to adjust the amplification gain of the receiving link. The AGC coefficient determines the amplification factor of the received signal by the analog front-end or digital gain module, directly affecting the signal amplitude entering the synchronization calculation module.

[0081] After determining that the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, the signal receiving device locks the gain control coefficient, that is, fixes the currently used gain control coefficient to the current value and prohibits the adaptive adjustment of the gain control coefficient, so that the gain remains unchanged in the subsequent synchronization process.

[0082] It should be noted that the purpose of locking the gain control coefficient is to prevent changes in the amplitude of the synchronization signal already captured by the first communication band from occurring due to gain adjustments triggered during subsequent synchronization calculations of other bands when the received signal may be detected simultaneously by multiple frequency bands, especially overlapping bands. This ensures the comparability of peak parameters for each band during multi-band cross-verification. In some implementations, the signal receiving device records the current gain control coefficient at the locking moment and writes it to a read-only register or flag bit. Subsequent energy comparison and gain adjustment loops are suspended until the gain control coefficient is unlocked.

[0083] Subsequently, the signal receiving device continues to perform synchronization calculations in each preset communication frequency band. If the synchronization calculation result of the second communication frequency band meets the initial synchronization condition, and its second peak parameter meets the preset comparison condition with the first peak parameter obtained in the most recent update, then the synchronization result of the first communication frequency band is determined to be a missynchronization. At this time, the signal receiving device first unlocks the gain control coefficient and restores the adaptive adjustment capability of the gain control coefficient.

[0084] After unlocking, the signal receiving device readjusts the gain control coefficient based on the signal energy of the second communication frequency band. In some implementations, the signal receiving device uses the received signal on the second communication frequency band as a reference and dynamically adjusts the gain control coefficient according to the comparison between the signal energy within a preset time window and a preset energy threshold (e.g., increasing the gain when the signal energy is below the threshold and decreasing the gain when it is above the threshold), so that the signal amplitude entering the synchronization calculation module is stable within the ideal dynamic range. When the synchronization calculation result of the second communication frequency band again meets the initial synchronization condition (e.g., continuously detecting correlation peaks of a preset number threshold), the signal receiving device locks the adjusted gain control coefficient to ensure that the gain remains constant during the subsequent determination of the target synchronization position based on the second communication frequency band.

[0085] In the above embodiments, through a collaborative mechanism of gain locking, unlocking, and relocking, the gain is locked immediately after the initial synchronization condition is met in the first communication frequency band. This establishes a constant and comparable gain benchmark for the subsequent dynamic update of the first peak parameter and the comparison of peak values ​​across multiple frequency bands, avoiding peak parameter distortion caused by continuous gain adjustment. When the first communication frequency band is determined to be missynchronized and the signal is switched to the second communication frequency band, the gain is first unlocked so that the gain coefficient can be re-adapted according to the actual signal energy of the second communication frequency band. Then, the gain is relocked after the synchronization of the second communication frequency band is stable, ensuring that the signal amplitude during the synchronization calculation of the second communication frequency band is within the optimal dynamic range. This not only ensures the fairness of cross-validation but also improves the reliability of synchronization after switching, significantly improving the accuracy and robustness of signal synchronization in multi-frequency band, low signal-to-noise ratio, and frequency band overlapping scenarios.

[0086] In some embodiments, adjusting the gain control coefficient based on the signal energy of the second communication frequency band specifically includes: determining multiple signal sampling points within a preset symbol period in the second communication frequency band; and adjusting the gain control coefficient according to the comparison result between the signal energy of each sampling point and the target energy range.

[0087] After switching to the second communication frequency band and unlocking the gain lock, the signal receiving device first performs synchronization calculations in the second communication frequency band to detect correlation peaks. When the first valid correlation peak is detected, the signal receiving device uses the signal sampling point corresponding to the correlation peak (i.e., the sampling point at the moment the correlation peak appears) as the adjustment reference, obtains the signal strength (e.g., absolute amplitude or power value) of the sampling point, and compares it with the target energy range.

[0088] After adjusting based on the comparison results, the signal receiving device continues to detect subsequent correlation peaks and repeats the gain adjustment operation for the sampling point corresponding to each newly detected correlation peak. This process continues until the number of consecutive correlation peaks detected exceeds a preset threshold (e.g., 3 or 4 consecutive correlation peaks).

[0089] After the number of consecutive correlation peaks meets the requirement, the signal receiving device determines multiple signal sampling points within a preset symbol period (e.g., one OFDM symbol length). In some embodiments, the multiple signal sampling points may include a continuous range of sampling points extending forward and backward from the correlation peak position, or all sampling points within the entire symbol period. The signal receiving device calculates signal strength statistics (e.g., average amplitude, root mean square amplitude, or energy sum) for these sampling points and compares these statistics with a target energy range.

[0090] It should be noted that during multi-band synchronization, the gain control of the received signal is usually performed independently of the synchronization detection stage; that is, the AGC loop continuously and dynamically adjusts the gain based on the instantaneous energy of the received signal. However, when using a multi-band cross-validation mechanism, this continuously dynamically adjusted gain can lead to serious problems: because the signal energy in different frequency bands may differ (e.g., the main band signal is stronger while the sub-band signal is weaker), if the gain is locked after detecting the synchronization result of the first communication band, but the signal energy of the second communication band is different during subsequent verification, the locked gain may not be suitable for the synchronization calculation of the second communication band, resulting in distortion of the peak parameters of the second communication band and affecting the fairness of the cross-comparison. Conversely, if the gain is allowed to continue to adjust during the verification process, the gain during synchronization of the first communication band will be inconsistent with the gain during synchronization of the second communication band, making the peak parameters of the two bands incomparable.

[0091] Based on this, in some embodiments, the gain control coefficient is obtained by adjusting the currently used gain control coefficient based on the comparison result between the signal energy of the sampling point and the target energy range; wherein: when the signal energy of the sampling point is lower than the target energy range, the currently used gain control coefficient is increased; when the signal energy of the sampling point is within the target energy range, the currently used gain control coefficient is kept unchanged; when the signal energy of the sampling point is higher than the target energy range, the currently used gain control coefficient is decreased.

[0092] The gain control coefficient is a parameter expressed in numerical form. Generally, the larger the gain control coefficient, the greater the amplification of the received signal; the smaller the gain control coefficient, the smaller the amplification.

[0093] The target energy range refers to the reference energy value pre-configured inside the signal receiving device to determine whether the current signal energy is appropriate. It is usually determined by a combination of the full-scale range of the analog-to-digital converter, the dynamic range of the subsequent digital processing module, and the system's tolerance to signal distortion. The purpose is to ensure that the amplitude of the signal input to the synchronization calculation module is neither too small (to avoid the influence of quantization noise) nor too large (to avoid saturation distortion).

[0094] Signal energy refers to the sum of the squares or absolute values ​​of the amplitudes of each sampling point of the received signal within a preset time window, and is used to characterize the total strength of the signal during that time period.

[0095] After synchronization is initiated, the signal receiving device continuously monitors the energy changes of the received signal and dynamically adjusts the gain control coefficient to ensure that the signal energy remains near a preset energy threshold. In some embodiments, the signal receiving device periodically calculates the signal energy of the received signal within a preset time window.

[0096] Subsequently, the signal receiving device adjusts the currently used gain control coefficients (including analog gain control coefficients and / or digital gain control coefficients) based on the comparison results between the signal energy of the received signal within the preset time window and the target energy range.

[0097] In the above embodiments, a closed-loop adaptive control of the received signal energy is achieved through the adjustment mechanism of the gain control coefficient. This ensures that the signal amplitude entering the synchronization calculation module remains within the ideal dynamic range under different signal strengths and frequency bands, thereby enabling the correlation peak detection to have both sensitivity and accuracy. Furthermore, the gain is immediately locked when the candidate frequency band meets the initial synchronization conditions, avoiding unnecessary gain adjustments triggered by subsequent synchronization calculations of other frequency bands. This creates a constant signal amplitude environment for comparing peak parameters across multiple frequency bands.

[0098] By utilizing the sampling points corresponding to the correlation peaks for rapid coarse adjustment, the gain can be quickly adjusted to a roughly appropriate range in the early stages of the synchronization signal, avoiding the slow response problem of traditional energy detection methods. In addition, by using the condition that the number of consecutive correlation peaks exceeds a preset threshold, the interference of noise spikes on gain adjustment is effectively suppressed. Fine adjustment is then performed based on multiple sampling points within a preset symbol period, ensuring that the signal amplitude is within the ideal dynamic range throughout the entire symbol period. This provides a higher quality input signal for subsequent channel estimation and data demodulation, significantly improving synchronization reliability and signal quality in complex channel environments such as low signal-to-noise ratio, frequency band overlap, and multipath.

[0099] In related technologies, multi-band synchronization methods often treat each preset communication frequency band as a completely independent channel with no spectral overlap, and perform synchronization detection and result comparison based on this. However, in practical applications of power line carrier communication, due to limitations in spectrum resource utilization and communication standard regulations, multiple operating frequency bands are often not completely isolated, but rather have varying degrees of partial overlap. For example, some power line communication standards define a main frequency band and one or more sub-bands (such as extended bands after center frequency shift), and the frequency ranges of these sub-bands have significant overlap with the main frequency band. If this physical characteristic is ignored during the design phase, and overlapping frequency bands are treated as independent frequency bands for synchronization decision, the following problems may arise: On the one hand, strong signals on the main frequency band can severely interfere with the synchronization detection of sub-bands through spectral leakage, causing frequent false correlation peaks in the sub-bands; on the other hand, real synchronization signals on sub-bands can also interfere with the main frequency band, making it difficult for signal receiving equipment to accurately determine which frequency band the synchronization signal originates from. If the coexistence relationship between the main frequency band and the sub-frequency band and their partial overlap characteristics are not clearly defined, the subsequent cross-validation, the setting of the preset overlap coefficient, and the logic for detecting missynchronization may lose their physical basis, making it difficult to specifically solve the problem of inter-frequency band interference.

[0100] Based on this, in some embodiments, multiple preset communication frequency bands include a main frequency band and a sub-frequency band, and the frequency range of the sub-frequency band partially overlaps with the frequency range of the main frequency band; wherein, the first communication frequency band is one of the main frequency band and the sub-frequency band, and the second communication frequency band is the other.

[0101] The primary frequency band refers to the default communication frequency band used by the signal receiving device as the main synchronization detection channel. In some implementations, the primary frequency band has a large bandwidth or a high signal-to-noise ratio, and is the preferred frequency band for synchronization signal transmission.

[0102] A sub-band refers to a preset communication frequency band other than the main frequency band, used to assist in synchronization detection or as a backup synchronization channel. In some implementations, the center frequency of the sub-band may be the same as or different from that of the main frequency band, and its bandwidth may be less than or equal to that of the main frequency band.

[0103] Partial overlap refers to a situation where the frequency range of a sub-band and the frequency range of the main band overlap in the spectrum, but they do not completely coincide; that is, each includes frequency components not covered by the other. For example, if the main band's frequency range is 0.5 MHz to 2.5 MHz and the sub-band's frequency range is 1.5 MHz to 3.5 MHz, then they overlap in the 1.5 MHz to 2.5 MHz range.

[0104] The signal receiving device is pre-configured with at least one primary frequency band and one sub-frequency band, wherein the frequency ranges of the primary and sub-frequency bands partially overlap. During synchronization, the signal receiving device performs synchronization calculations on both the primary and sub-frequency bands and independently monitors the correlation peaks in each band. When the synchronization calculation result of a certain frequency band (e.g., the primary frequency band) first meets the initial synchronization condition, that frequency band is designated as the first communication frequency band. Subsequently, if the synchronization calculation result of another frequency band (e.g., the sub-frequency band) also meets the initial synchronization condition, and its peak parameter meets a preset comparison condition with the first peak parameter, then the synchronization result of the first communication frequency band is determined to be a missynchronization, and the other frequency band is designated as the second communication frequency band, i.e., the frequency band where the true synchronization signal resides. Conversely, if the first communication frequency band is the primary frequency band, and the sub-frequency band has never met the initial synchronization condition or its peak parameter does not meet the comparison condition, then the synchronization result of the primary frequency band is confirmed as true synchronization. Similarly, if a sub-band first meets the initial synchronization condition, then the sub-band is the first communication band, and the main band is used as the second communication band for cross-verification.

[0105] In the above embodiments, by setting a main frequency band and partially overlapping sub-frequency bands in multiple preset communication frequency bands, a basic architecture conforming to the actual power line communication spectrum planning is constructed for the multi-band synchronization method. This allows subsequent gain locking, cross-validation, and missynchronization determination to be optimized to address the inherent energy leakage characteristics between the main and sub-frequency bands. Furthermore, when channel conditions are good, the synchronization result of the main frequency band can be trusted by default; when the channel is interfered with or the main frequency band experiences severe fading, the sub-frequency bands can serve as reliable backup synchronization channels. This significantly improves the synchronization robustness and adaptability of the power line carrier communication system in complex channel environments without increasing additional spectrum resources.

[0106] Furthermore, when there is frequency overlap among multiple preset communication frequency bands, using the same local synchronization sequence to perform cross-correlation detection on the received signals of different frequency bands will create new problems: Since the main frequency band and sub-band partially overlap in the spectrum, if the two frequency bands use the exact same synchronization sequence, when the receiving device detects the synchronization signal on the main frequency band, the cross-correlation result on the sub-band due to energy leakage will also show a significant correlation peak; and vice versa. This cross-band cross-correlation pseudo-peak makes it difficult for the receiving device to distinguish which frequency band the real synchronization signal originates from, thus generating a large number of missynchronizations during multi-band cross-verification. For example, when the real synchronization signal only exists in the sub-band, the main frequency band may also generate a cross-correlation peak similar to that of the sub-band due to energy leakage. If the same synchronization sequence is used, the peak parameters of the two frequency bands will be highly similar, causing the missynchronization discrimination mechanism based on peak parameter comparison to fail.

[0107] Based on this, in some embodiments, when the frequency ranges of the sub-band and the main band partially overlap, the main band and the sub-band are synchronized using synchronization sequences generated based on different phase rotation factors.

[0108] The phase rotation factor refers to the complex coefficients used when performing phase modulation on the original synchronization sequence, and is usually expressed as: or .in For rotation angle, For subcarrier index, The sequence length is given. By applying different phase rotation factors to the same original synchronization sequence, a set of derived sequences with weak cross-correlation can be generated.

[0109] A synchronization sequence refers to a reference signal sequence pre-stored in a signal receiving device for cross-correlation detection with the received signal. Synchronization sequences generated based on different phase rotation factors refer to two or more sets of sequences obtained by multiplying the same original synchronization sequence as a base sequence by different phase rotation factors. The cross-correlation value between these two sets of sequences is much lower than their respective autocorrelation peaks with themselves, thus achieving approximate orthogonality of synchronization sequences in different frequency bands in the frequency or time domain.

[0110] The signal receiving device pre-stores an original synchronization sequence and generates corresponding local synchronization sequences for the main frequency band and sub-frequency bands respectively. In some implementations, for the main frequency band, the signal receiving device directly uses the original synchronization sequence (equivalent to a phase rotation factor of 1) as the local synchronization sequence for the main frequency band. For the sub-frequency bands, the signal receiving device applies a phase rotation factor different from that of the main frequency band to the original synchronization sequence, thereby generating a local synchronization sequence specific to the sub-frequency band. In other implementations, the specific value of the phase rotation factor can be optimized based on the center frequency difference between the main frequency band and the sub-frequency band, the bandwidth overlap ratio, and the system's requirements for sequence cross-correlation performance.

[0111] During the synchronization calculation, the signal receiving equipment performs cross-correlation operations on the main frequency band using its local synchronization sequence and on the sub-frequency band using its local synchronization sequence. Because the cross-correlation between the synchronization sequences used in the two frequency bands is relatively weak, even if leakage energy from the main frequency band is mixed into the received signal of the sub-frequency band, the cross-correlation result of the sub-frequency band will not produce obvious spurious peaks due to the mismatch between the leakage signal and the sub-frequency band's local synchronization sequence. Similarly, the cross-correlation result of the main frequency band will not be significantly interfered with by the leakage signal of the sub-frequency band. Therefore, the correlation peaks detected in each of the two frequency bands mainly reflect the actual synchronization signal existing in that band, while cross-band energy leakage is effectively suppressed.

[0112] In the above embodiments, by using synchronization sequences generated based on different phase rotation factors to perform synchronization calculations on the main frequency band and sub-frequency bands, multi-band synchronization detection can distinguish signals from different frequency bands, thus complementing the aforementioned preset overlap coefficient. The preset overlap coefficient corrects for leakage at the comparison level, while this embodiment actively suppresses leakage at the physical level. The two work synergistically, reducing the interference intensity of the leakage signal through orthogonal synchronization sequences and further filtering the influence of residual leakage through adaptive comparison thresholds. This significantly improves the accuracy and reliability of multi-band synchronization detection in complex spectral environments with overlapping frequency bands, providing better input for subsequent gain locking and cross-validation.

[0113] While multi-band cross-verification mechanisms can effectively identify and correct missynchronization caused by frequency band overlap or interference, in practical applications, the following situation may occur: the first communication band has met the initial synchronization conditions and locked its gain, while other communication bands (such as a sub-band or another of the main bands) fail to meet the initial synchronization conditions due to channel fading, noise interference, or the absence of their own synchronization signals. In this case, if the signal receiving equipment continues to wait for verification results from other bands, the synchronization process may be delayed indefinitely, or even fail. On the other hand, if the synchronization result of the first communication band is discarded directly without verification from other bands, a truly valid synchronization signal may be missed, reducing the probability of signal synchronization acquisition.

[0114] Based on this, in some embodiments, when the synchronization calculation results of other communication frequency bands besides the first communication frequency band do not meet the initial synchronization condition, the received signal is synchronized based on the synchronization calculation results of the first communication frequency band.

[0115] The statement that the synchronization calculation results of all communication frequency bands other than the first communication frequency band do not meet the initial synchronization condition means that after the signal receiving device completes the gain lock of the first communication frequency band, it continues to perform synchronization calculations on all preset communication frequency bands other than the first communication frequency band, and within the preset time window or detection window, the synchronization calculation results of these frequency bands fail to meet the conditions required for the initial synchronization determination.

[0116] After locking the gain control coefficient of the first communication frequency band and recording the first peak parameter, the signal receiving device starts a timer or sets a maximum verification time window. Within this time window, the signal receiving device continues to perform synchronization calculations and cross-verifications on the remaining communication frequency bands. If, before the end of the time window, the synchronization calculation result of any of the remaining communication frequency bands meets the initial synchronization condition and its peak parameter meets the preset comparison condition, the first communication frequency band is determined to be missynchronized, and the device switches to the second communication frequency band to re-establish synchronization. Conversely, if, after the time window expires, the synchronization calculation results of all the remaining communication frequency bands fail to meet the initial synchronization condition (i.e., no second communication frequency band meets the condition), the signal receiving device determines that the synchronization result of the first communication frequency band is genuine and valid.

[0117] In this scenario, the signal receiving device continues to perform synchronization calculations on the received signal based on the synchronization calculation results of the first communication frequency band. Specifically, the signal receiving device maintains the currently locked gain control coefficient unchanged, and this gain coefficient is adjusted and locked based on the signal energy of the first communication frequency band. It continues to perform synchronization calculations in the first communication frequency band to detect subsequent correlation peaks and determine the target synchronization position of the received signal based on the position of the negative correlation peak. Afterward, the signal receiving device can further perform subsequent processing such as fine frequency offset estimation, channel estimation, and data demodulation.

[0118] In the above embodiments, the received signal is synchronized based on the synchronization calculation result of the first communication frequency band when the synchronization calculation results of the other communication frequency bands do not meet the initial synchronization conditions. This avoids synchronization deadlock or timeout failure caused by waiting for verification of other frequency bands, and allows the synchronization process to be completed within a certain time. This makes the entire synchronization method robust and available in complex and ever-changing power line channel environments.

[0119] In some embodiments, when a correlation peak is detected in any communication frequency band, channel estimation is performed on the received signal to obtain a channel estimation result; wherein the channel estimation result is used to perform channel equalization on the received signal.

[0120] Channel estimation refers to the process by which a signal receiving device estimates the channel frequency response or impulse response experienced by the signal using a known training sequence (such as a long training field or pilot symbols) in the received signal. The channel estimation result refers to the channel parameters calculated through channel estimation, including but not limited to the channel frequency response, channel impulse response, channel gain on each subcarrier, phase offset, and signal-to-noise ratio estimates.

[0121] Channel equalization refers to the process of using channel estimation results to compensate the received signal in order to counteract the effects of multipath fading, amplitude attenuation, and phase rotation, and to recover the original modulation symbols from the transmitter.

[0122] When a signal receiving device performs synchronization calculations in any preset communication frequency band, it triggers the channel estimation process once a valid correlation peak is detected (e.g., cross-correlation or autocorrelation results exceed a dynamic threshold). Specifically, based on the synchronization position indicated by the detected correlation peak, the signal receiving device extracts a training sequence (such as a long training field) from the received signal, compares it with locally known training sequences, and calculates the channel estimation result using methods such as least squares, least mean square error, or correlation operations. This channel estimation result is stored and used for subsequent channel equalization, i.e., performing inverse filtering on the data field of the received signal in the frequency or time domain to eliminate channel distortion.

[0123] In some implementations, when a missynchronization is determined and the gain control coefficient is unlocked, the signal receiving device clears the channel estimation result of the first communication frequency band to zero, so that the channel estimation after the switch starts from an unbiased state again.

[0124] When the signal receiving device determines that the synchronization result of the first communication band is a missynchronization and performs a gain control coefficient unlocking operation, it simultaneously clears the currently stored channel estimation result to zero. This is because unlocking the gain control coefficient means that the amplification factor of the receiving link will change, and the synchronization band will switch from the first communication band to the second communication band. The original channel estimation result, calculated based on the incorrect band and the old gain conditions, is completely invalid. If it is not cleared, when re-estimating the channel based on the second communication band, the old data may be mixed into the new estimation result through filtering or iterative algorithms, causing the channel estimator to fail to converge correctly.

[0125] After the channel estimation is cleared and the gain is relocked based on the second communication band, when the signal receiving device detects the correlation peak again in the second communication band, it performs channel estimation again to obtain the correct channel estimation result, which is then used for subsequent channel equalization.

[0126] In the above embodiments, by associating channel estimation with correlation peak detection, invalid calculations are effectively avoided. In addition, while determining missynchronization and unlocking the gain control coefficient, the channel estimation result is cleared, so that the channel estimation result after switching to the correct frequency band has purity and fast convergence, thereby significantly improving the accuracy of channel estimation and the reliability of data demodulation in multi-band, low signal-to-noise ratio and frequency band overlapping scenarios.

[0127] In the complex channel environment of power line carrier communication, impulse noise, sudden interference, or energy leakage between frequency bands can easily generate isolated spurious correlation peaks in a certain frequency band. If the initial synchronization condition is determined to be met based solely on a single peak value, and this single peak value is used as the first peak parameter for subsequent cross-validation, the probability of missynchronization increases significantly. This leads to subsequent gain locking and synchronization position determination based on the wrong frequency band, ultimately affecting the reliability of the entire communication link.

[0128] Based on this, in some embodiments, when the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, the first peak parameter of the first communication frequency band is determined, specifically including: when the synchronization calculation result based on the first communication frequency band determines that a continuous correlation peak is detected, the initial synchronization condition is met; and the average value of the peak values ​​corresponding to the continuous correlation peaks is obtained as the first peak parameter.

[0129] In this context, a correlation peak refers to a peak whose amplitude significantly exceeds the background noise level in the correlation result obtained by the signal receiving device after performing synchronization calculations (such as cross-correlation or autocorrelation). Typically, the appearance of a correlation peak indicates a high degree of matching between the received signal and the local synchronization sequence at that moment. Continuously detected correlation peaks refer to multiple correlation peaks that appear sequentially in time, with the time interval between two adjacent correlation peaks conforming to a preset period (e.g., the length of an OFDM symbol, allowing for a certain deviation tolerance). The detection of continuous correlation peaks utilizes the inherent periodic repetition characteristic of synchronization sequences (such as SYNCP in a preamble sequence), meaning that the real synchronization signal will repeatedly exhibit the same or alternating correlation peaks at fixed intervals (e.g., the number of sampling points corresponding to an OFDM symbol). The peak average is the value obtained by arithmetically averaging the peak amplitudes of multiple continuously detected valid correlation peaks.

[0130] The signal receiving device first performs synchronization calculations in the first communication frequency band to detect correlation peaks. In some embodiments, the signal receiving device uses a sliding window approach to perform cross-correlation calculations between the local synchronization sequence corresponding to the first communication frequency band and the received signal, and performs autocorrelation enhancement processing on the cross-correlation results to obtain a correlation value sequence. Simultaneously, based on the periodic characteristics of the synchronization sequence, the signal receiving device predicts the time window in which the next valid correlation peak may appear (e.g., the current peak position plus an OFDM symbol length). In subsequent synchronization calculations, if another valid correlation peak is detected within the predicted time window, the signal receiving device determines that consecutive correlation peaks have been detected, and the synchronization calculation results in the first communication frequency band meet the initial synchronization condition. After determining that the initial synchronization condition is met, the signal receiving device acquires the peak amplitudes of the detected consecutive valid correlation peaks and calculates the arithmetic mean of these peaks, using this average as the first peak parameter.

[0131] In some embodiments, the signal receiving device determines that a continuous correlation peak has been detected based on the synchronization calculation result under the first communication frequency band. Specifically, this includes: performing synchronization calculation on the received signal under the first communication frequency band to detect the correlation peak; counting the continuously detected correlation peaks; and determining that the synchronization calculation result under the first communication frequency band indicates that a continuous correlation peak has been detected if the count value is greater than or equal to a preset number threshold.

[0132] The preset threshold number refers to the minimum number of correlation peaks required to determine successful detection of consecutive correlation peaks, which is pre-configured within the signal receiving device. For example, the preset threshold number can be a fixed value (e.g., 2, 3, or 4), or it can be dynamically adjusted based on the channel quality, signal-to-noise ratio estimate, or system configuration of the current communication frequency band.

[0133] The signal receiving device performs synchronization calculations in the first communication frequency band to detect correlation peaks. After detecting a valid correlation peak, the signal receiving device records the position of the current peak. Subsequently, based on the periodic characteristics of the synchronization sequence, the signal receiving device predicts the search window in which the next valid correlation peak may appear, and continues to perform synchronization calculations within this search window. If another valid correlation peak is detected within this window, the continuous correlation peak counter is incremented, and the prediction of the next search window is continued based on the position of the previous correlation peak. If no valid correlation peak is detected within this search window, it is determined that the continuous correlation peak detection has been interrupted, the counter is reset to zero, and counting starts again from the next newly detected correlation peak.

[0134] The current count value of the continuous correlation peak counter is compared with a preset quantity threshold. In scenarios requiring rapid synchronization, the preset quantity threshold can be set to, for example, 2 or 3. When the count value is greater than or equal to the preset quantity threshold, the signal receiving device determines that the synchronization calculation result under the first communication frequency band has indicated the detection of a continuous correlation peak, i.e., the initial synchronization condition is met.

[0135] In the above embodiments, by detecting continuous correlation peaks and obtaining the average peak value, the signal receiving device can effectively filter out isolated spurious correlation peaks caused by impulse noise, inter-band energy leakage, or sudden interference, thereby significantly reducing the probability of missynchronization. Simultaneously, using the average peak value of continuous correlation peaks as the first peak parameter further smooths the peak amplitude fluctuations caused by channel fading or multipath effects, providing a more stable and reliable comparison benchmark for subsequent cross-validation with the second peak parameter of the second communication band, thus enhancing the robustness and accuracy of the multi-band synchronization method.

[0136] Furthermore, by using a continuous correlation peak counting method based on a preset threshold, a clear quantitative standard and configurable judgment threshold are provided for the detection of continuous correlation peaks. Compared to uncertain judgments that rely on experience or the number of simple peak occurrences, this method can effectively eliminate isolated peaks or false peaks caused by random noise, thereby significantly reducing the probability of false alarms. Moreover, the preset threshold can be flexibly adjusted according to the channel characteristics of different communication frequency bands or the system's requirements for synchronization reliability, enabling the multi-band synchronization method to adaptively adapt to different application scenarios, balancing synchronization speed and synchronization reliability.

[0137] Figure 3 This is a schematic diagram of the gain control and signal processing link architecture in a signal receiving device provided in some embodiments of the present invention. For example... Figure 3 As shown, the signal receiving device receives an analog power line carrier signal. This analog signal first undergoes initial amplitude adjustment through an analog gain control module, then anti-aliasing filtering through an analog filter, and is subsequently converted into a digital baseband signal by an analog-to-digital converter. The digital signal further undergoes noise suppression and channel shaping filtering through a digital filter before entering the synchronization module to perform multi-band synchronization calculations. To achieve closed-loop adaptive control of signal energy, the signal receiving device extracts the average signal energy within a preset time window before and during synchronization processing, and feeds this energy information back to the analog gain control and digital gain control stages, respectively. The analog gain control is used to coarsely adjust the overall amplification factor of the receiving link to avoid signal saturation or weakness before analog-to-digital conversion; the digital gain control is used to finely adjust the amplitude of the digital signal after analog-to-digital conversion to compensate for residual errors in the analog gain adjustment, ensuring that the signal energy entering the synchronization module is stable near a preset energy threshold.

[0138] In some embodiments, the target synchronization position of the received signal is determined based on the synchronization calculation results after relocking the gain control coefficient. Specifically, this includes: continuing to perform synchronization calculation in the second communication frequency band to detect subsequent correlation peaks; and when a negative correlation peak is detected, determining the target synchronization position of the received signal based on the negative correlation peak.

[0139] Among them, the subsequent correlation peak refers to the correlation peak detected by continuing to perform synchronous calculation in the second communication frequency band after the gain control coefficient is relocked, including positive correlation peak and negative correlation peak; while the negative correlation peak refers to the peak point in the cross-correlation or autocorrelation calculation result where the correlation value is negative and the absolute value exceeds the preset threshold.

[0140] In the frame structure of power line carrier communication, the negative correlation peak corresponds to the position of the SYNCM sequence, which is usually located at the end of the preamble sequence, followed immediately by data fields (such as frame control headers or payloads). Therefore, there is a fixed time offset between the position of the negative correlation peak and the start position of the data frame.

[0141] The target synchronization position refers to the precise sampling point position in the received signal used to mark the start of a data frame or the boundary of an OFDM symbol, such as the starting position of a Fast Fourier Transform (FFT) window or the starting position of the first data symbol.

[0142] After the signal receiving device completes gain relocking in the second communication frequency band, it continues to perform synchronization calculations in the second communication frequency band to detect subsequent correlation peaks. Specifically, the signal receiving device uses the local synchronization sequence corresponding to the second communication frequency band (e.g., a synchronization sequence dedicated to the main frequency band or sub-frequency band) to perform sliding cross-correlation and autocorrelation operations with the received signal, and monitors the correlation value sequence in real time. Since the gain control coefficient has been locked and the signal energy is stable, the shape and amplitude of the correlation peaks are highly predictable. The details of locking the gain control coefficient have been explained in the previous embodiments and will not be repeated here.

[0143] Subsequently, the signal receiving device searches for peak points in the correlation value sequence. In some implementations, for positive correlation peaks, the correlation value is positive and the amplitude is high, corresponding to the matching position of SYNCP; for negative correlation peaks, the correlation value is negative and the absolute value is high, corresponding to the matching position of SYNCM. The signal receiving device can set a negative threshold (e.g., a negative cross-correlation threshold). When the correlation value is less than or equal to the negative threshold and is the minimum value in its neighborhood, a valid negative correlation peak is determined to be detected, and the signal receiving device records the sampling point index position corresponding to the negative correlation peak.

[0144] According to the frame structure of power line carrier communication, there is a fixed offset between the position of the negative correlation peak and the target synchronization position. For example, if the protocol specifies that the Mth sampling point after SYNCM is the starting position of the first data symbol (i.e., the starting position of the FFT window), then the target synchronization position is the sum of the negative correlation peak position and M. Here, M can be a positive value (negative correlation peak first, data second) or a negative value (negative correlation peak second, data first), depending on the design of the synchronization sequence. Finally, the signal receiving device calculates the final target synchronization position based on this offset.

[0145] In some implementations, to improve the accuracy of the synchronization position determination, the signal receiving device can further perform interpolation calculations by combining multiple sampling points before and after the negative correlation peak after detecting the negative correlation peak. For example, it can use quadratic interpolation or the centroid method to estimate a more accurate peak position, thereby obtaining a more accurate target synchronization position.

[0146] In the above embodiments, the target synchronization position is determined by using the negative correlation peak under the second communication frequency band. Compared with using the positive correlation peak (which may appear in the middle of the preamble sequence), the positioning ambiguity is reduced. Since the gain control coefficient has been relocked and kept stable based on the second communication frequency band, the amplitude and shape of the negative correlation peak will not be affected by gain fluctuations, thus improving the accuracy and reliability of the final synchronization position in the multi-frequency band overlap and interference environment.

[0147] Figure 4 This is a schematic diagram of the multi-band synchronization calculation process provided in some embodiments of the present invention. For example... Figure 4 As shown, the signal receiving device performs synchronization calculations on both frequency band A and frequency band B for the received power line carrier signal. In the frequency band A branch, the signal receiving device performs the synchronization calculation corresponding to frequency band A (e.g., using the local synchronization sequence of frequency band A for cross-correlation and autocorrelation operations) to obtain the synchronization calculation result for frequency band A. This result is then compared with a preset threshold; when the synchronization result exceeds the threshold, a correlation peak in frequency band A is detected. Similarly, in the frequency band B branch, the signal receiving device independently performs the synchronization calculation corresponding to frequency band B, compares the synchronization calculation result of frequency band B with the threshold, and detects a correlation peak in frequency band B when the conditions are met. Through parallel or time-division processing, the signal receiving device can obtain correlation peak detection results for multiple frequency bands. These multi-band correlation peaks will be used for subsequent cross-validation. For example, if frequency band A first meets the initial synchronization conditions and its gain is locked, and if frequency band B subsequently also detects a correlation peak and its peak parameter meets the preset comparison conditions with frequency band A, then the synchronization result of frequency band A is determined to be a missynchronization, and synchronization is re-established based on frequency band B.

[0148] Figure 5 This is a schematic diagram of the overall process of the multi-band synchronization method provided in some embodiments of the present invention. For example... Figure 5As shown, the signal receiving device performs synchronization calculations on frequency bands A and B respectively. In the frequency band A branch, when the consecutive correlation peak count (i.e., Begincount) reaches a preset threshold (Begincount equals 2), the initial synchronization condition is determined to be met. At this time, the peak value of the correlation peak in frequency band A is acquired (if multiple peaks exist, the average value Peak1 is taken), and the device enters the SYNCBegin (i.e., synchronization) state to begin channel estimation and lock the automatic gain control (AGC) gain coefficient. Afterward, the signal receiving device continues to synchronously search for correlation peaks on both frequency bands A and B. When the synchronization calculation of frequency band B detects a continuous correlation peak (Begincount=2), and the peak value Peak2 of frequency band B satisfies Peak2≥Peak1×a (where a is a preset overlap coefficient and a>1), the synchronization result of frequency band A is determined to be a missynchronization. The AGC gain coefficient is unlocked, and the channel estimation result is cleared. Then, the next orthogonal frequency division multiplexing (OFDM) symbol corresponding to the current correlation peak position of frequency band B is used for AGC adjustment and relocking, and channel estimation begins based on this next OFDM symbol. After that, the search for correlation peaks continues until the position of the negative correlation peak is found based on the synchronization calculation of frequency band B, thereby determining the target synchronization position. If the peak value of frequency band B does not satisfy the above comparison condition (i.e., Peak2≥Peak1×a), the signal receiving device does not perform frequency band switching, but continues to search for correlation peaks based on the synchronization calculation of frequency band A until the position of the negative correlation peak is found based on the synchronization calculation of frequency band A, and synchronization is completed accordingly.

[0149] The multi-band synchronization method for power line carrier signals provided in this embodiment of the invention can be executed by a multi-band synchronization device for power line carrier signals. This embodiment of the invention uses the execution of the multi-band synchronization method for power line carrier signals by a multi-band synchronization device as an example to illustrate the multi-band synchronization device for power line carrier signals provided in this embodiment of the invention.

[0150] Figure 6 This is a schematic diagram of the structure of a multi-band synchronization device for power line carrier signals provided in some embodiments of the present invention. For example... Figure 6 As shown, the power line carrier signal multi-band synchronization device includes: a first synchronization module 601, a detection module 602, a second synchronization module 603, and a determination module 604.

[0151] The first synchronization module 601 is used to perform synchronization calculations on the received signals under multiple preset communication frequency bands to obtain the synchronization calculation results corresponding to each communication frequency band. The detection module 602 is used to determine the first peak parameter of the first communication frequency band when the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, and to update the first peak parameter according to the new correlation peak when a new correlation peak is detected in the future. The second synchronization module 603 is used to continue to perform synchronization calculations on the received signals under each preset communication frequency band; The determination module 604 is used to determine the target synchronization position of the received signal in the second communication frequency band if the synchronization calculation result of the second communication frequency band meets the initial synchronization condition and the second peak parameter of the second communication frequency band meets the preset comparison condition with the first peak parameter obtained in the most recent update.

[0152] The power line carrier signal multi-band synchronization device provided in this embodiment of the invention performs synchronization calculations on the received signal in parallel under multiple preset communication frequency bands, enabling the synchronization results of each frequency band to verify each other. This avoids the missed detection problem caused by only detecting a single frequency band, which leads to the signal receiver not being able to predict the actual frequency band of the signal transmitter in a multi-band network. This provides a data basis for subsequent frequency band selection. When the first communication frequency band meets the initial synchronization condition, a first peak parameter is determined, and this parameter is continuously updated when a new correlation peak is detected. This ensures that the first peak parameter reflects the latest signal condition under the current channel conditions, avoiding reference deviation caused by the influence of instantaneous noise or fading on the early peak. The device continues to detect signals under this dynamic reference. If the second communication frequency band also meets the initial synchronization conditions and its second peak parameter meets the preset comparison conditions with the first peak parameter obtained in the most recent update, then the synchronization is switched to the second communication frequency band. This allows the real frequency band with a higher peak value to identify and correct the false correlation peak that appears first in a communication frequency band under conditions of frequency band overlap or low signal-to-noise ratio. At the same time, since the first peak parameter is dynamically updated as the comparison benchmark, it can adapt to the time-varying characteristics of the channel and avoid misjudgment or omission caused by a fixed benchmark. This significantly reduces the false synchronization rate and shortens the recovery time. Finally, the target synchronization position is determined based on the correct second communication frequency band, thereby improving the signal synchronization accuracy in low signal-to-noise ratio and frequency band overlap scenarios.

[0153] In some embodiments, the detection module is further configured to lock the gain control coefficient when the synchronization calculation result of the first communication frequency band meets the initial synchronization condition; if the synchronization calculation result of the second communication frequency band meets the initial synchronization condition and the second peak parameter of the second communication frequency band meets the preset comparison condition with the first peak parameter obtained in the most recent update, the lock on the gain control coefficient is released; the gain control coefficient is adjusted based on the signal energy of the second communication frequency band, and the adjusted gain control coefficient is locked.

[0154] In some embodiments, the detection module is further configured to determine multiple signal sampling points within a preset symbol period in the second communication frequency band, and adjust the gain control coefficient based on the comparison result between the signal energy of each sampling point and the target energy range.

[0155] In some embodiments, the second synchronization module is further configured to perform synchronization calculation on the received signal based on the synchronization calculation result of the first communication band when the synchronization calculation results of other communication bands besides the first communication band do not meet the initial synchronization condition.

[0156] In some embodiments, the second synchronization module is further configured to perform channel estimation on the received signal when a correlation peak is detected in any communication frequency band, and obtain a channel estimation result; the channel estimation result is used to perform channel equalization on the received signal.

[0157] In some embodiments, the detection module is further configured to determine that the initial synchronization condition is met if a continuous correlation peak is detected based on the synchronization calculation results under the first communication frequency band; and to determine the first peak parameter based on the average peak value of the continuous correlation peak.

[0158] In some embodiments, the detection module is further configured to perform synchronous calculation on the received signal in the first communication frequency band to detect correlation peaks; count the continuously detected correlation peaks, and determine that the synchronous calculation result in the first communication frequency band indicates that continuous correlation peaks have been detected if the count value exceeds a preset number threshold.

[0159] The power line carrier signal multi-band synchronization 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.

[0160] The power line carrier signal multi-band synchronization device provided in this embodiment of the invention can realize the various processes implemented in the above-described power line carrier signal multi-band synchronization method embodiment. To avoid repetition, these processes will not be described again here.

[0161] In some embodiments, Figure 7 These are schematic diagrams of the structure of an electronic device provided in some embodiments of the present invention. For example... Figure 7 As shown, this embodiment of the invention also provides an electronic device 700, including a processor 701, a memory 702, and a computer program stored in the memory 702 and executable on the processor 701. When the program is executed by the processor 701, it implements the various processes of the above-described power line carrier signal multi-band synchronization method embodiment and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0162] 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 above-described power line carrier signal multi-band synchronization method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0163] 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.

[0164] The computer-readable storage medium may include: read-only memory (ROM), random-access memory (RAM), magnetic disk or optical disk, etc.

[0165] This invention provides a computer program product, including a computer program that, when executed by a processor, implements the above-described power line carrier signal multi-band synchronization method.

[0166] 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 above-described power line carrier signal multi-band synchronization method embodiments and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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 multi-band synchronization of power line carrier signals, characterized in that, include: Synchronization calculations are performed on the received signals under multiple preset communication frequency bands to obtain the synchronization calculation results corresponding to each communication frequency band; When the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, the first peak parameter of the first communication frequency band is determined, and when a new correlation peak is detected subsequently, the first peak parameter is updated according to the new correlation peak. Continue to perform synchronous calculations on the received signals under each preset communication frequency band; If the synchronization calculation result of the second communication frequency band satisfies the initial synchronization condition, and the second peak parameter of the second communication frequency band satisfies the preset comparison condition with the first peak parameter obtained in the most recent update, the target synchronization position of the received signal is determined in the second communication frequency band.

2. The multi-band synchronization method for power line carrier signals according to claim 1, characterized in that, The second peak parameter of the second communication frequency band satisfies a preset comparison condition with the first peak parameter obtained in the most recent update, including: the second peak parameter is greater than or equal to the product of the first peak parameter obtained in the most recent update and a preset overlap coefficient; wherein the preset overlap coefficient is greater than 1.

3. The multi-band synchronization method for power line carrier signals according to claim 1, characterized in that, The method further includes: When the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, the gain control coefficient is locked. If the synchronization calculation result of the second communication frequency band satisfies the initial synchronization condition, and the second peak parameter of the second communication frequency band satisfies the preset comparison condition with the first peak parameter obtained in the most recent update, the lock on the gain control coefficient is released. The gain control coefficient is adjusted based on the signal energy of the second communication frequency band, and the adjusted gain control coefficient is locked.

4. The multi-band synchronization method for power line carrier signals according to claim 3, characterized in that, The adjustment of the gain control coefficient based on the signal energy of the second communication frequency band includes: Multiple signal sampling points within a preset symbol period are determined in the second communication frequency band; The gain control coefficient is adjusted based on the comparison between the signal energy at each sampling point and the target energy range.

5. The multi-band synchronization method for power line carrier signals according to claim 1, characterized in that, The plurality of preset communication frequency bands include a main frequency band and a sub-frequency band, wherein the frequency range of the sub-frequency band partially overlaps with the frequency range of the main frequency band; wherein, the first communication frequency band is one of the main frequency band and the sub-frequency band, and the second communication frequency band is the other.

6. The multi-band synchronization method for power line carrier signals according to claim 5, characterized in that, When the frequency ranges of the sub-band and the main band partially overlap, the main band and the sub-band are synchronized using synchronization sequences generated based on different phase rotation factors.

7. The multi-band synchronization method for power line carrier signals according to claim 1, characterized in that, The method further includes: When the synchronization calculation results of other communication frequency bands besides the first communication frequency band do not meet the initial synchronization condition, the received signal is synchronized based on the synchronization calculation results of the first communication frequency band.

8. The multi-band synchronization method for power line carrier signals according to claim 1, characterized in that, The method further includes: When a correlation peak is detected in any communication frequency band, channel estimation is performed on the received signal to obtain the channel estimation result; the channel estimation result is used to perform channel equalization on the received signal.

9. The multi-band synchronization method for power line carrier signals according to claim 1, characterized in that, When the synchronization calculation result of the first communication frequency band meets the initial synchronization condition, the first peak parameter of the first communication frequency band is determined, including: If a continuous correlation peak is detected based on the synchronization calculation results under the first communication frequency band, it is determined that the initial synchronization condition is met. The first peak parameter is determined based on the average peak value of the continuous correlation peaks.

10. The multi-band synchronization method for power line carrier signals according to claim 9, characterized in that, The determination of the detection of continuous correlation peaks based on the synchronization calculation results under the first communication frequency band includes: The received signal is synchronously calculated in the first communication frequency band to detect relevant peaks; The continuously detected correlation peaks are counted, and if the count value exceeds a preset threshold, the synchronous calculation result under the first communication frequency band is determined to indicate that the continuously detected correlation peaks are detected.

Images