Public network downlink receiver clock frequency deviation estimation method based on linear fitting

Abstract

The invention relates to the technical field of wireless communication, and discloses a public network downlink receiver clock frequency deviation estimation method based on linear fitting, which comprises the following steps of: monitoring a public network synchronization channel and capturing a frame header signal through a receiver; the frame header signal comprises a plurality of frame header signals, a data packet header, a synchronization frame of a broadcast signal and a key frame for frequency deviation estimation, and recording a timestamp received by a receiver when the frame header signal is captured each time; analyzing the timestamp of the frame header signal by using a linear fitting algorithm, and estimating the clock frequency deviation between the receiver and the base station through a minimum error function; a clock of the receiver is adjusted based on the estimated clock frequency offset. By introducing a frequency interpolation technology, a dynamic adjustment mechanism and multi-path effect compensation, the clock synchronization precision is remarkably improved, the receiver is ensured to stably operate in signal loss, interference and complex environments, and the robustness and reliability of the system are improved.

Description

Technical Field

[0001] The invention relates to the technical field of wireless communications, and in particular to a method for estimating a clock frequency deviation of a public network downlink receiver based on linear fitting. Background Art

[0002] In modern communication systems, clock synchronization is the core technology to ensure data transmission accuracy and system reliability. Especially in public network downlink receivers, the estimation and synchronization of clock frequency deviation directly affects signal reception and demodulation. In wireless communications, there is often a certain deviation in the clock frequency between the receiver and the base station. If this deviation cannot be corrected in time, it will cause signal distortion or even data loss.

[0003] In the prior art, clock synchronization mainly relies on capturing the timestamp data of the frame header signal and estimating the clock deviation by analyzing the arrival time of the signal. Based on these technologies, clock frequency deviation estimation can maintain the synchronization of the system to a certain extent, especially in an environment with good signal quality, these methods can achieve more accurate clock synchronization. At the same time, the prior art also has a certain multipath effect compensation capability and can handle some common signal interference and fluctuations. The existing method can be well applied in a relatively stable wireless environment, and its calculation method is relatively simple, which can quickly complete the clock synchronization task.

[0004] However, the existing technology still has obvious shortcomings when facing complex environments, especially in cases of signal loss, severe interference or multipath propagation. Traditional methods usually rely on a single frame header signal, the accuracy of frequency deviation estimation is low, and it is easily affected by signal jitter and noise, resulting in inaccurate synchronization. More seriously, when the base station signal is lost or interfered, the existing technology cannot predict and fill the frequency deviation during the signal interruption through interpolation and other technologies, which easily causes clock synchronization interruption. In addition, the existing technology is not precise enough in correcting the clock frequency deviation caused by multipath propagation, and cannot fully utilize the signal strength distribution and arrival time difference, resulting in insufficient synchronization accuracy. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method for estimating the clock frequency deviation of a public network downlink receiver based on linear fitting, which solves the problems in the prior art of insufficient frequency deviation estimation accuracy, clock synchronization interruption due to signal loss or interference, and inaccurate clock synchronization in a multipath propagation environment.

[0006] To achieve the above purpose, the present invention is implemented by the following technical scheme: a method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting, comprising the following steps:

[0007] Monitor the public network synchronization channel through the receiver and capture the frame header signal, wherein the frame header signal includes multiple frame header signals, data packet headers, synchronization frames of broadcast signals and key frames for frequency deviation estimation, and record the timestamp received by the receiver each time the frame header signal is captured;

[0008] The timestamp of the frame header signal is analyzed using a linear fitting algorithm, and the clock frequency deviation between the receiver and the base station is estimated by minimizing the error function.

[0009] adjusting the receiver clock based on the estimated clock frequency deviation so that the received signal is synchronized with the base station signal;

[0010] When the base station signal is lost or interfered, the receiver clock frequency deviation is dynamically adjusted based on the timestamp data of the captured frame header signal and the frequency deviation estimation result obtained by the linear fitting algorithm;

[0011] When the base station signal is interrupted, the frequency interpolation technology is used to predict and fill the clock frequency deviation during the signal interruption period;

[0012] In a multipath propagation environment, the timestamp data is corrected using multipath effect modeling and signal delay compensation algorithms based on the intensity distribution and time arrival difference information of the received frame header signal.

[0013] Preferably, the linear fitting algorithm comprises:

[0014] The timestamp data of multiple captured frame header signals are analyzed using the least square method, and the clock frequency deviation between the receiver and the base station is estimated by minimizing the error between the signal timestamp and the ideal timestamp;

[0015] The linear fitting algorithm optimizes the frequency deviation estimation results through the fitting process.

[0016] Preferably, the dynamic adjustment includes:

[0017] When a new frame header signal is received, the receiver clock frequency deviation is adjusted in real time according to the frequency deviation estimation result at the previous moment and the current signal timestamp data;

[0018] The receiver ensures that the timing of the signal is synchronized with the base station by dynamically adjusting the deviation value.

[0019] Preferably, the frequency interpolation includes:

[0020] The receiver uses the historical frame header signal timestamp data captured during the signal interruption period and combines it with the linear fitting result to predict the clock deviation at the future moment, and interpolates to fill in the clock frequency change during the signal loss period.

[0021] The interpolation algorithm can accurately estimate the receiver clock deviation during the signal loss period based on the change trend of the previous frequency deviation.

[0022] Preferably, the timestamp data analysis includes:

[0023] Linear fitting is performed on the timestamp data of multiple frame header signals to estimate the frequency deviation of the receiver clock by minimizing the difference between the signal arrival timestamp and the ideal timestamp;

[0024] The fitting process optimizes the error in the calculation process and finally obtains the precise frequency deviation between the receiver clock and the base station clock.

[0025] Preferably, the modified timestamp data includes:

[0026] Based on the intensity distribution and time arrival difference of the captured frame header signal, the signal timing data is corrected by using multipath effect modeling;

[0027] During the correction process, the accuracy of clock frequency deviation estimation is further optimized by compensating for the time deviation caused by multipath propagation during signal transmission.

[0028] Preferably, the frame header signal capturing includes:

[0029] The receiver continuously monitors the public network synchronization channel and records the timestamp data of each captured signal by detecting multiple frame header signals and key frames of other signals;

[0030] During the signal acquisition process, the receiver classifies and marks different synchronization signal types.

[0031] Preferably, the minimizing error function comprises:

[0032] Minimize the error between the captured timestamp data of multiple frame header signals and the reference timestamp of the base station, optimize the fitting function, and obtain the best estimate of the clock frequency deviation;

[0033] By ensuring the minimization of the error function, the deviation caused by external noise, interference and multipath effects is reduced.

[0034] Preferably, the signal delay compensation includes:

[0035] According to the propagation characteristics of the received frame header signal, combined with the arrival time difference of the signal and the intensity distribution of the multipath signal, the time delay caused by the multipath effect is compensated by modeling;

[0036] Through multipath compensation, the timestamp data can be accurately estimated and corrected, further improving the accuracy of frequency deviation estimation.

[0037] Preferably, the base station signal synchronization includes:

[0038] During the estimation of the clock frequency deviation between the receiver and the base station, the clock synchronization state of the receiver is continuously updated;

[0039] Pre-process the captured frame header signal to optimize the timing of the signal and ensure that the signal is synchronized with the base station after frequency deviation calibration;

[0040] During the frequency deviation estimation process, real-time monitoring technology is used to evaluate the quality of the signal.

[0041] The present invention provides a method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting, which has the following beneficial effects:

[0042] 1. The present invention adopts a frequency deviation estimation method based on linear fitting, and estimates the frequency deviation between the receiver and the base station by capturing the frame header signal and timestamp data multiple times, thereby achieving the technical effect of improving the accuracy of clock synchronization. Compared with the method of capturing a single signal and estimating the frequency deviation in the prior art, the present invention can effectively reduce the influence of interference and noise by capturing multiple frame signals, ensuring that the clock synchronization in a complex wireless environment is more stable and reliable.

[0043] 2. The present invention introduces a dynamic adjustment mechanism, which monitors the signal status in real time and dynamically adjusts the receiver clock based on the frequency deviation estimation result, thereby achieving the technical effect of maintaining clock synchronization in the case of base station switching and signal loss. Compared with the static frequency deviation estimation method in the prior art, the present invention can quickly respond to changes in signal quality and avoid the synchronization error problem caused by traditional methods during signal interference or switching.

[0044] 3. The present invention uses frequency interpolation technology to compensate for the clock deviation during signal interruption. Even when the base station signal is lost, the receiver can still maintain high-precision clock synchronization, achieving the technical effect of maintaining clock continuity. Compared with the defect of the prior art that cannot handle long-term signal loss, the present invention can use the previous frequency deviation estimation results to predict and fill the clock deviation during the signal loss, avoiding clock synchronization interruption.

[0045] 4. The present invention uses multipath effect compensation technology, combined with the strength of the received frame header signal and the arrival time difference, to correct the clock frequency deviation caused by multipath propagation, thereby achieving the technical effect of improving the accuracy of clock synchronization. Compared with the method of lacking effective compensation for multipath propagation in the prior art, the present invention can accurately correct the timestamp data, thereby significantly reducing the error caused by the multipath effect on clock synchronization and improving the robustness of the system in complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the method flow of the present invention. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] Please see attached Figure 1 The embodiment of the present invention provides a method for estimating a clock frequency deviation of a public network downlink receiver based on linear fitting, comprising the following steps:

[0049] S1. The receiver monitors the public network synchronization channel and captures the frame header signal, which includes multiple frame header signals, data packet headers, synchronization frames of broadcast signals, and key frames for frequency deviation estimation. Each time the frame header signal is captured, the timestamp received by the receiver is recorded;

[0050] By performing timestamp analysis on the captured multiple frame header signals, one of the key steps of this embodiment is to further process these timestamp data through a linear fitting algorithm to estimate the clock frequency deviation between the receiver and the base station. To this end, in this process, the accuracy and real-time performance of capturing and recording timestamps are crucial for the subsequent frequency deviation estimation.

[0051] In general, the receiver continuously monitors the public network synchronization channel and receives various synchronization signals. The synchronization signal type can be multiple frame header signals, data packet headers, broadcast signal synchronization frames, etc. Each synchronization signal has certain synchronization characteristics, and the receiver needs to identify and process these signals. When capturing these signals, the receiver records the timestamp information of the current signal in real time. In order to ensure the accuracy of the estimation of the clock frequency deviation, the receiver must not only capture the frame header signal, but also ensure that the recorded timestamp has high accuracy and reliability.

[0052] For example, the receiver can use the signal frame header, broadcast synchronization frame, etc. as a synchronization reference point. These synchronization signals can be key frames in the signal frame that is broadcast or transmitted. For example, the data packet header may contain relevant information about time synchronization, and the synchronization frame of the broadcast signal can be used as a global synchronization reference.

[0053] In the process of capturing each signal, the receiver records the timestamp of each frame header signal arrival. For each captured signal, the receiver will accurately record the current time. The purpose of this is to compare these timestamps with the ideal timestamp of the base station through subsequent data processing, and then estimate the frequency deviation of the receiver clock. Specifically, the clock deviation between the receiver clock and the base station clock may occur due to factors such as temperature fluctuations and power supply fluctuations. These deviations are estimated and adjusted through subsequent algorithms.

[0054] When capturing the frame header signal, the receiver compares the received signal with the standard time through precise hardware and software synchronization mechanisms and records the accurate timestamp. The timestamp data will be stored and passed to the next analysis module for subsequent processing.

[0055] For example, in one embodiment, the receiver forms a timestamp data set by frequently capturing and recording the timestamps of the signals. ,These data will be used in the subsequent frequency deviation estimation step.,The captured data not only include the timestamp of the frame header signal, but may also,involve the timestamp data of other important signals such as the,broadcast synchronization frame.

[0056] As an option, the receiver can classify and mark each frame header signal by detecting different types of synchronization signals. For example, the receiver can distinguish which signals are packet headers and which are key frames for frequency deviation estimation. Each signal has a different synchronization method, and the receiver will classify them according to the characteristics of different signals so that the appropriate synchronization signal can be selected for analysis in the subsequent frequency deviation estimation process.

[0057] Specifically, the receiver can set different marking rules. For the frequency deviation estimation key frames, the receiver will first capture and record these signals because the important synchronization information they carry can provide a more accurate reference for frequency deviation estimation. In order to ensure synchronization accuracy, the receiver can also selectively capture based on factors such as the strength and transmission path of different signals.

[0058] A core technical point of the present invention is the accuracy of recording timestamp data. During the signal capture process, the receiver must not only record the timestamp, but also ensure the reliability of the timestamp data. Since wireless signals are affected by many factors during transmission, such as noise, interference, and multipath propagation, each timestamp record must be strictly calibrated and verified to ensure its accuracy.

[0059] In some embodiments, the receiver uses a high-precision hardware clock and a software algorithm to accurately synchronize the captured signal. The received timestamp includes not only the time when the receiver actually captured the signal, but also takes into account factors such as propagation delay and environmental influences, and performs necessary time synchronization calibration.

[0060] During this process, each time stamp recorded by the receiver Ideal timestamp with base station The deviation between will be analyzed by linear fitting algorithm. Specifically, the receiver clock frequency deviation estimation process is performed by the following formula:

[0061] ;

[0062] in, For the The time deviation of the signal; The actual timestamp recorded by the receiver, is the ideal timestamp. After analyzing the timestamps of multiple signals through a linear fitting algorithm, the clock frequency deviation between the receiver and the base station can be obtained. and propagation delay .

[0063] Through the above steps, the receiver can generate an accurate clock frequency deviation estimation result and then adjust the clock synchronization to ensure that it is consistent with the base station's clock.

[0064] S2, analyzing the timestamp of the frame header signal using a linear fitting algorithm, and estimating the clock frequency deviation between the receiver and the base station by minimizing the error function;

[0065] After the receiver captures the frame header signal in the public network synchronization channel and records the timestamp, it uses a linear fitting algorithm to analyze the captured timestamp data. This analysis estimates the clock frequency deviation between the receiver and the base station by minimizing the error function. This process follows the signal capture and timestamp recording in the previous steps. Its purpose is to achieve accurate synchronization between the receiver clock and the base station clock through accurate analysis of the frame header signal timestamp.

[0066] Generally, when the receiver monitors and captures the frame header signal, it will record the corresponding timestamp. These timestamp data are used for subsequent frequency deviation estimation. The timestamp of each frame header signal It is the signal arrival time captured by the receiver according to the local clock. These timestamps are consistent with the ideal timestamp of the base station. There is a certain deviation between them. The receiver needs to estimate the clock frequency deviation by analyzing these timestamp data.

[0067] During this analysis, the receiver estimates the frequency deviation by minimizing the following error function:

[0068] ;

[0069] in, is the ideal timestamp; is the number of captured frame header signals; is the clock frequency deviation between the receiver and the base station. When solving this function, we get This is the frequency deviation of the receiver; : Error function, representing the receiver clock frequency deviation The corresponding estimation error, the goal is to minimize the error function to obtain the best clock frequency deviation estimate; The first The actual timestamp of the frame header signal.

[0070] Through the fitting process, the receiver can optimize the estimated value of the frequency deviation based on the captured timestamp data. Specifically, the fitting process optimizes the fitting results based on the timestamps of multiple frame header signals to ensure that the error function is minimized, so that the clock frequency deviation between the receiver and the base station is minimized. This step is crucial to improving the accuracy of clock synchronization.

[0071] For example, if in actual application, the receiver obtains the timestamp from multiple frame header signals , then by linearly fitting the errors of these timestamps, the receiver can calculate the frequency deviation from the base station clock Specifically, the fitting process optimizes the error in the calculation process and finally obtains the precise frequency deviation between the receiver clock and the base station clock.

[0072] In the implementation process, minimizing the error function is one of the key steps. In the minimization process, the receiver accumulates the differences between all captured timestamp data and the base station reference timestamp, and obtains the best frequency deviation estimate by calculating the minimum value of the sum of squared errors. This process not only helps to eliminate clock deviations caused by factors such as noise, interference or multipath effects, but also provides high-precision clock frequency deviation estimation results in complex communication environments.

[0073] By minimizing the error function, the receiver can accurately estimate the clock frequency deviation, thereby improving the accuracy of time synchronization. For example, in an environment where the signal is interfered, by minimizing the error function, the receiver can effectively reduce the impact of external noise and further improve synchronization accuracy.

[0074] In some embodiments, the receiver may combine more signal features (such as phase information, channel estimation, etc.) for more accurate fitting analysis. By introducing more complex signal analysis techniques, the accuracy of frequency deviation estimation can be further optimized, especially in the case of poor signal quality or complex network environment.

[0075] In addition, the fitting process may involve more advanced mathematical methods, such as weighted least squares method, to deal with the reliability differences of certain frame header signals. The weighted least squares method can reduce the influence of unreliable frame header signals on the fitting results by weighting them, thereby further improving the accuracy of the overall frequency deviation estimation.

[0076] S3, adjusting the receiver clock based on the estimated clock frequency deviation so that the received signal is synchronized with the base station signal;

[0077] After the receiver completes the capture of the frame header signal, records the timestamp, and estimates the clock frequency deviation through the linear fitting algorithm, the receiver will adjust its local clock based on the estimated frequency deviation to synchronize the received signal with the base station's signal. This step is a natural continuation of the aforementioned signal capture and frequency deviation estimation, and its purpose is to ensure that the receiver can accurately synchronize to the base station's clock so that the signal can be demodulated according to the correct timing.

[0078] The process of adjusting the receiver clock involves the receiver correcting its clock frequency in real time based on the estimated frequency deviation, thereby ensuring that the received signal is in sync with the base station signal. This step is critical for the stable transmission and decoding of subsequent signals.

[0079] Generally, after the receiver completes signal capture and estimates the clock frequency deviation through a linear fitting algorithm, the receiver will To adjust its clock so that the received signal is synchronized with the base station signal. In a typical implementation, the receiver will adjust the clock according to the following formula:

[0080] ;

[0081] in, is the adjusted receiver clock time; is the actual timestamp recorded by the receiver; It is the ideal timestamp for the base station; is the clock frequency deviation estimated by the aforementioned linear fitting algorithm.

[0082] Specifically, the receiver will use the frequency deviation Calculate the value that needs to be adjusted for the local clock. If it is a positive value, the receiver clock needs to reduce the timestamp; if it is a negative value, it needs to increase the timestamp. This adjustment ensures that the timing of the received signal is consistent with the base station signal, avoiding data errors caused by inconsistent clock frequencies.

[0083] As an option, the receiver continuously monitors and adjusts the clock frequency deviation. In some embodiments, the receiver may perform multiple clock adjustment operations to gradually optimize the synchronization accuracy of the clock. At each adjustment, the receiver will adjust the clock frequency based on the estimated frequency deviation. Dynamically adjust the clock to ensure that the timing of the signal is synchronized with the base station signal.

[0084] In a possible implementation, the receiver continuously captures the frame header signal and dynamically adjusts the clock frequency in combination with the estimated frequency deviation. This process can further eliminate the influence of noise and interference in the signal and ensure that the receiver clock gradually approaches the ideal synchronization state of the base station clock.

[0085] In some embodiments, the receiver may also combine other signal characteristics, such as signal strength, transmission distance, etc., to further optimize the clock adjustment. Through multi-dimensional information analysis, the receiver can achieve more accurate clock synchronization and maintain high-precision frequency deviation estimation and clock synchronization in complex environments.

[0086] Specifically, the receiver can also use an adaptive algorithm to predict the changing trend of frequency deviation and make clock adjustments in advance. This prediction algorithm can improve the response speed of clock adjustment and enable the receiver to quickly adapt to changes in base station signals in a dynamic environment.

[0087] To improve the accuracy of clock adjustment, the receiver may use incremental adjustment instead of large-scale clock adjustment at one time. Incremental adjustment helps reduce interference with the received signal and avoids signal errors that may be caused by large-scale frequency deviation adjustment.

[0088] In addition, the receiver may evaluate the accuracy of the frequency deviation adjustment in real time and adjust the strategy according to the actual effect. This real-time feedback mechanism can effectively improve the stability of clock synchronization, especially in environments with frequent base station switching or unstable signal quality.

[0089] S4, when the base station signal is lost or interfered, dynamically adjust the receiver clock frequency deviation according to the timestamp data of the captured frame header signal and the frequency deviation estimation result obtained by the linear fitting algorithm;

[0090] When the receiver loses the base station signal or is interfered with, the receiver can dynamically adjust its clock frequency deviation through the captured frame header signal timestamp data and the frequency deviation estimation result obtained by the linear fitting algorithm. This adjustment method is closely connected with the clock frequency deviation estimation in the previous step, ensuring that the receiver can still maintain a high clock synchronization accuracy in the case of signal loss or interference.

[0091] Specifically, in the case of signal loss or interference, the receiver will dynamically adjust the clock based on the historically captured frame header signal timestamp data and the frequency deviation results estimated by the linear fitting algorithm in the early stage. This process ensures that even when the signal is interrupted or the quality is reduced, the receiver's clock can still be automatically corrected according to the estimated frequency deviation trend, avoiding system errors caused by clock inconsistency.

[0092] Generally, when the receiver receives the frame header signal normally, it has completed the preliminary estimation of the clock frequency deviation and uses this estimation result to synchronize the base station clock. If the base station signal is lost or interfered during the reception process, the receiver will not be able to obtain new timestamp data immediately, and may not be able to make immediate clock synchronization adjustments. Therefore, the receiver will dynamically adjust the clock frequency based on the previous frequency deviation estimation results combined with the currently captured partial or historical frame header signal data.

[0093] Specifically, the receiver uses the previously estimated frequency deviation And previously captured signal timestamp data This process ensures that the receiver clock is adjusted according to the previously estimated trend during periods of signal loss.

[0094] In a typical embodiment, the receiver may use the following formula to dynamically adjust the frequency deviation:

[0095] ;

[0096] in, is the adjusted clock frequency deviation; is the frequency deviation estimated previously; is the rate of change of frequency deviation; It was the last moment; It is the present moment; Represents a small time interval or increment, usually used for variables in integration. This interpolation method is based on the trend of previous frequency deviations and can continue to synchronize the clocks until the signal is restored.

[0097] Specifically, when the receiver detects a signal interruption or severe interference, it adjusts the clock based on historical data. Instead of waiting for the signal to recover, the receiver actively uses the previous frequency deviation estimate to predict the clock frequency deviation at future times. The key to this process is to predict future frequency deviation changes through interpolation calculations, and then adjust the receiver clock to keep it close to the base station clock.

[0098] For example, the receiver obtains the frequency deviation based on the linear fitting algorithm obtained earlier. and the corresponding timestamp , combined with the timestamp data of the currently captured partial frame header signal, an interpolation algorithm is used to predict the frequency deviation at the current moment. By adjusting the frequency deviation of the receiver clock, the receiver can continue to maintain clock synchronization before the signal is restored, ensuring accurate demodulation of subsequent signals.

[0099] As an option, the receiver can further adjust the clock synchronization strategy based on the quality assessment of the external signal. When the received frame header signal is severely interfered, the receiver will increase the weight of the previous frequency deviation estimation result to reduce the impact of noise on clock synchronization. When the interference is small or the signal quality is good, the receiver can further optimize the clock synchronization through the real-time updated timestamp data.

[0100] In one possible implementation, when the receiver finds that the base station signal is lost for more than a certain period of time or the strength changes too much, it can use frequency interpolation technology to fill the clock frequency deviation during the signal interruption period. Through this prediction mechanism, the receiver can adjust the clock frequency deviation in advance to ensure the continuity of time synchronization.

[0101] By dynamically adjusting the clock frequency deviation, the receiver can continue to maintain clock synchronization when the base station signal is lost or interfered, avoiding data loss and communication errors caused by clock inconsistency. This technology can significantly improve the robustness of the receiver in complex network environments, especially in scenarios with frequent base station switching or large radio environment interference.

[0102] For example, when the network environment changes, the receiver can dynamically adjust the clock frequency deviation to ensure that the clock synchronization is accurately maintained even when there is no signal or the signal quality is low, until a new signal is received for clock correction.

[0103] S5. When the base station signal is interrupted, the frequency interpolation technology is used to predict and fill the clock frequency deviation during the signal interruption period;

[0104] When the receiver is interrupted by the base station signal during the communication process, the frequency interpolation technology is used to predict and fill the clock frequency deviation during the signal interruption to ensure that the receiver clock continues to be synchronized with the base station clock. This step plays an important role in the aforementioned clock frequency deviation estimation and dynamic adjustment process. When the receiver cannot update the clock frequency deviation through the conventional frame header signal, the clock frequency deviation is compensated through the frequency interpolation technology, so that the receiver can continue to stably receive the signal and avoid clock synchronization interruption caused by signal loss.

[0105] Specifically, during the period of base station signal interruption, frequency interpolation technology uses an interpolation algorithm to predict the receiver's clock frequency deviation change based on the previous frequency deviation estimation results and historical timestamp data, and fills the deviation gap caused by signal loss. This process not only reduces the clock error caused by signal loss, but also provides an accurate clock synchronization reference for signal recovery.

[0106] Generally, the receiver, in normal working state, relies on the received frame header signal and the synchronization information of the base station to continuously update the clock frequency deviation. However, in the case of signal interruption or severe quality degradation, the receiver will not be able to obtain new frame header signal data to update the clock frequency deviation. In order to ensure that the receiver can continue to maintain high-precision clock synchronization before the signal is restored, this embodiment adopts frequency interpolation technology to fill the gap of clock frequency deviation during signal interruption.

[0107] Specifically, the receiver uses a frequency interpolation algorithm to calculate the frequency deviation based on the previous estimate. and historical timestamp data , predict the changing trend of the clock deviation, and use the interpolation method to fill the clock frequency change during the signal interruption. The interpolation algorithm calculates the changing trend of the frequency deviation to obtain the expected frequency deviation of the receiver clock during the signal interruption, and adjusts the local clock of the receiver accordingly.

[0108] In one possible implementation, the receiver can use weighted interpolation technology to consider the reliability and accuracy of different timestamp data and use a weighted method to interpolate the frequency deviation. The weighted interpolation method can adjust the interpolation accuracy according to the signal quality and the update frequency of the timestamp, further improving the accuracy of clock synchronization.

[0109] In this weighted interpolation method, newer timestamp data and more reliable frequency deviation estimates will have a greater impact on the interpolation calculation results. This allows the receiver clock to predict the expected clock frequency deviation as accurately as possible before signal recovery.

[0110] In order to further improve the accuracy of clock synchronization, in some embodiments, the receiver can also adjust the interpolation process multiple times based on real-time feedback. Each time a new signal is received, the receiver can re-estimate the frequency deviation and correct the previous interpolation result. This dynamic adjustment interpolation method can more accurately reflect the clock deviation changes in the actual environment and ensure the stability of the clock synchronization process.

[0111] Specifically, the receiver can also combine feedback information such as real-time signal quality and clock synchronization accuracy, and use an adaptive interpolation strategy to automatically adjust the parameters of the interpolation algorithm for different environmental conditions. Through this adaptive interpolation, the receiver can flexibly adjust the clock synchronization strategy under different wireless channel conditions to cope with the challenges brought by various complex environments.

[0112] By introducing frequency interpolation technology, the present invention can effectively fill the clock frequency deviation during signal interruption and avoid clock synchronization interruption caused by signal loss or interference. When the receiver cannot obtain new signal data, it can still maintain high-precision synchronization with the base station clock, providing a reliable clock reference for subsequent signal recovery and demodulation.

[0113] The application of frequency interpolation technology enables the receiver to dynamically adjust its clock frequency deviation during signal interruption, thereby improving the robustness of the system. Especially in the case of frequent base station switching or large interference in the wireless environment, the receiver can rely on historical data and interpolation prediction to maintain the continuity of clock synchronization, significantly improving the stability and reliability of the system.

[0114] S6. In a multipath propagation environment, based on the intensity distribution and time arrival difference information of the received frame header signal, the timestamp data is corrected using multipath effect modeling and signal delay compensation algorithm.

[0115] When the receiver is in a multipath propagation environment, the timestamp data is corrected by using the strength distribution of the received frame header signal, the time arrival difference and other information, combined with multipath effect modeling and signal delay compensation algorithm. This step is closely connected with the aforementioned clock frequency deviation estimation and dynamic adjustment process. In a multipath propagation environment, the signal will go through multiple propagation paths, and the signal arrival time of each path may be different, resulting in time errors in the received signal. In order to improve the accuracy of clock synchronization, the receiver uses multipath effect modeling to compensate for these errors and ensure the accuracy of the timestamp data.

[0116] Generally, in a wireless communication environment, a receiver may receive multiple signal copies from different propagation paths, and the arrival time and strength of these signal copies may be different. The multipath propagation effect will cause the time delay of the signal to change, thereby affecting the accuracy of the received timestamp data. To address this problem, this embodiment adopts a multipath effect modeling method based on signal strength distribution and time arrival difference, and corrects the timestamp data by compensating for the propagation delay of the signal.

[0117] Specifically, the receiver analyzes the propagation characteristics of each path based on the timestamp data and intensity distribution information of the received multiple frame header signals, and estimates the time deviation caused by each path. Then, the receiver applies multipath effect modeling and signal delay compensation algorithms to correct the timestamp error caused by multipath propagation, thereby improving the accuracy of clock synchronization.

[0118] In some embodiments, the receiver estimates the delays of multiple propagation paths by measuring the signal strength distribution and the arrival time differences of the received signals. The signal arrival time and strength of each path will be input as parameters into the multipath effect modeling algorithm for processing.

[0119] Specifically, the receiver corrects the error in the timestamp data by modeling the signal delay of each propagation path. The timestamp of the signal It is caused by the superposition effect of the arrival time of signals from multiple paths. The contribution to the timestamp can be expressed as:

[0120] ;

[0121] in, It is The actual receiving timestamp of the signal; is the ideal timestamp; It is The time deviation caused by the propagation path; is the number of paths for multipath propagation. The receiver corrects the captured timestamp data by modeling the delays of all paths.

[0122] Alternatively, the receiver can combine the signal strength and arrival time differences to more accurately model the multipath effect. Specifically, for each path, the receiver can estimate its contribution to clock synchronization based on the signal strength attenuation. Paths with stronger signal strength will have a greater impact on the final timestamp correction, while paths with weaker signal strength will contribute less to the timestamp.

[0123] In a possible implementation, the receiver can also use a weighted method to combine the strength information of different signal paths with the time delay to calculate the weight of each path's impact on the corrected timestamp data. Based on these weights, the receiver can perform weighted correction on the timestamp data to optimize the multipath compensation effect.

[0124] Specifically, during the correction process, the receiver optimizes the timestamp data through the following steps: first, the receiver determines the time delay of each path based on the multipath effect modeling algorithm; then, the receiver combines these time delays with the signal strength to calculate the contribution of each path to the final timestamp; finally, the receiver corrects the timestamp data based on this information to eliminate the errors caused by multipath propagation.

[0125] For example, suppose the signal received by the receiver contains signals from two paths, the signal strength of path 1 is stronger and arrives earlier, while the signal strength of path 2 is weaker and arrives later. The receiver will adjust the timestamp data based on the signal information of these two paths, reduce the time error caused by the multipath effect, and ensure that the final timestamp data is more accurate.

[0126] In order to further improve the accuracy of multipath compensation, the receiver can also use an adaptive algorithm to dynamically adjust the compensation strategy based on the signal quality and real-time measured timestamp data. When the signal quality is good, the receiver can use a simpler linear compensation model; when the signal quality is poor or the multipath effect is more serious, the receiver can use a more complex compensation algorithm, such as high-order interpolation or least squares fitting, to further improve the correction accuracy.

[0127] This adaptive compensation strategy can automatically select the most appropriate compensation method according to different communication environments and signal conditions, thereby ensuring synchronization accuracy in various environments.

[0128] By introducing multipath effect modeling and signal delay compensation algorithms, this embodiment can effectively eliminate clock frequency deviations caused by multipath propagation. The receiver reduces the error in signal arrival time by correcting the timestamp data, ultimately improving the accuracy of clock synchronization. In the case of poor signal quality or complex environment, this technology can significantly improve the clock synchronization stability of the receiver, ensuring that high-precision synchronization services can be provided even in a multipath propagation environment.

[0129] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting, characterized in that: The following steps are involved: Monitor the public network synchronization channel through the receiver and capture the frame header signal, wherein the frame header signal includes multiple frame header signals, data packet headers, synchronization frames of broadcast signals and key frames for frequency deviation estimation, and record the timestamp received by the receiver each time the frame header signal is captured; The timestamp of the frame header signal is analyzed using a linear fitting algorithm, and the clock frequency deviation between the receiver and the base station is estimated by minimizing the error function. adjusting the receiver clock based on the estimated clock frequency deviation so that the received signal is synchronized with the base station signal; When the base station signal is lost or interfered, the receiver clock frequency deviation is dynamically adjusted based on the timestamp data of the captured frame header signal and the frequency deviation estimation result obtained by the linear fitting algorithm; When the base station signal is interrupted, the frequency interpolation technology is used to predict and fill the clock frequency deviation during the signal interruption period; In a multipath propagation environment, the timestamp data is corrected using multipath effect modeling and signal delay compensation algorithms based on the intensity distribution and time arrival difference information of the received frame header signal.

2. The method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting according to claim 1, characterized in that: The linear fitting algorithm includes: The timestamp data of multiple captured frame header signals are analyzed using the least square method, and the clock frequency deviation between the receiver and the base station is estimated by minimizing the error between the signal timestamp and the ideal timestamp; The linear fitting algorithm optimizes the frequency deviation estimation results through the fitting process.

3. The method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting according to claim 1, characterized in that: The dynamic adjustment includes: When a new frame header signal is received, the receiver clock frequency deviation is adjusted in real time according to the frequency deviation estimation result at the previous moment and the current signal timestamp data; The receiver ensures that the timing of the signal is synchronized with the base station by dynamically adjusting the deviation value.

4. The method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting according to claim 1, characterized in that: The frequency interpolation includes: The receiver uses the historical frame header signal timestamp data captured during the signal interruption period and combines it with the linear fitting result to predict the clock deviation at the future moment, and interpolates to fill in the clock frequency change during the signal loss period. The interpolation algorithm can accurately estimate the receiver clock deviation during the signal loss period based on the change trend of the previous frequency deviation.

5. The method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting according to claim 1, characterized in that: The timestamp data analysis includes: Linear fitting is performed on the timestamp data of multiple frame header signals to estimate the frequency deviation of the receiver clock by minimizing the difference between the signal arrival timestamp and the ideal timestamp; The fitting process optimizes the error in the calculation process and finally obtains the precise frequency deviation between the receiver clock and the base station clock.

6. The method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting according to claim 1, characterized in that: The modified timestamp data includes: Based on the intensity distribution and time arrival difference of the captured frame header signal, the signal timing data is corrected by using multipath effect modeling; During the correction process, the accuracy of clock frequency deviation estimation is further optimized by compensating for the time deviation caused by multipath propagation during signal transmission.

7. The method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting according to claim 1, characterized in that: The frame header signal capture comprises: The receiver continuously monitors the public network synchronization channel and records the timestamp data of each captured signal by detecting multiple frame header signals and key frames of other signals; During the signal acquisition process, the receiver classifies and marks different synchronization signal types.

8. The method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting according to claim 1, characterized in that: The minimization error function comprises: Minimize the error between the captured timestamp data of multiple frame header signals and the reference timestamp of the base station, optimize the fitting function, and obtain the best estimate of the clock frequency deviation; By ensuring the minimization of the error function, the deviation caused by external noise, interference and multipath effects is reduced.

9. The method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting according to claim 1, characterized in that: The signal delay compensation comprises: According to the propagation characteristics of the received frame header signal, combined with the arrival time difference of the signal and the intensity distribution of the multipath signal, the time delay caused by the multipath effect is compensated by modeling; Through multipath compensation, the timestamp data can be accurately estimated and corrected, further improving the accuracy of frequency deviation estimation.

10. The method for estimating clock frequency deviation of a public network downlink receiver based on linear fitting according to claim 1, characterized in that: The base station signal synchronization includes: During the estimation of the clock frequency deviation between the receiver and the base station, the clock synchronization state of the receiver is continuously updated; Pre-process the captured frame header signal to optimize the timing of the signal and ensure that the signal is synchronized with the base station after frequency deviation calibration; During the frequency deviation estimation process, real-time monitoring technology is used to evaluate the quality of the signal.

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