Multi-frequency-point synchronous receiving Bluetooth communication modulation method

Abstract

The invention discloses a Bluetooth communication modulation method for multi-frequency-point synchronous receiving. The method comprises the following steps of: preprocessing a received signal, performing time-frequency analysis, extracting and locking instantaneous frequency waveform data, dynamically optimizing frequency point priority by combining signal strength and noise, calculating and optimizing gain and determining a transmission path; and the master control device synchronizes the clocks of the devices and then decodes the clocks in parallel, and finally obtains the final decoded data based on the multiplexing score and the weighting factor adjustment result. According to the method, stable signal transmission is achieved through time-frequency analysis, fast Fourier transform and frequency locking technologies, meanwhile, the frequency point priority and the transmission path are dynamically optimized based on the signal quality, and the method has the advantages of being high in frequency spectrum utilization rate, high in anti-interference performance, low in transmission delay and the like.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication, and particularly to a Bluetooth communication modulation method. Background Art

[0002] With the rapid development of wireless communication technology, Bluetooth has become an important technology for short-distance communication and is widely used in fields such as the Internet of Things, smart home, and wearable devices. Currently, electricity meters are also equipped with Bluetooth communication functions for signal transmission. However, in a complex environment, Bluetooth communication faces problems such as signal interference and insufficient frequency resources, which directly affect communication quality and stability.

[0003] Specifically, the existing Bluetooth communication methods have the following problems:

[0004] First, the existing communication methods adopt a frequency locking mechanism and lack dynamic adjustment capabilities, and cannot adapt to frequency deviations caused by environmental changes or device performance fluctuations in real time, resulting in a decline in signal stability and reliability.

[0005] Second, the frequency optimization and priority allocation of the existing communication methods are insufficient, so that the spectrum resources cannot be optimally utilized, and frequency conflicts or transmission interference cannot be effectively avoided.

[0006] Third, when dealing with frequency resources, the existing methods do not fully consider the priority of frequency points and the strength of device signals, and do not dynamically adjust the usage order of frequency points according to real-time data, resulting in unreasonable frequency point allocation or signal conflicts during signal transmission, increasing interference between devices, reducing the spectrum utilization efficiency of the overall system, having a lower decoding efficiency, and a larger transmission delay. Summary of the Invention

[0007] The present invention proposes a Bluetooth communication modulation method for multi-frequency point synchronous reception, and its purpose is to solve the problems existing in the existing communication methods, such as the lack of dynamic adjustment capabilities, insufficient utilization of spectrum resources, and failure to fully consider the priority of frequency points.

[0008] The technical solution of the present invention is as follows:

[0009] A Bluetooth communication modulation method for multi-frequency point synchronous reception, the steps include:

[0010] Step S1: Receive the signal from the transmitting device through a Bluetooth receiver and preprocess the signal;

[0011] Step S2: Perform time-frequency analysis on the preprocessed signal and extract the instantaneous frequency at each moment;

[0012] Step S3: Lock the frequency of the frequency waveform data composed of the extracted instantaneous frequencies;

[0013] Step S4: Based on the locked frequency data, combined with the signal strength data and noise data of the device, dynamically optimize the allocation priorities of each frequency point to obtain the priorities of each frequency point;

[0014] Step S5: Based on the frequency point priorities, calculate the optimized frequency point priorities and the optimized signal gains, and determine the signal transmission path;

[0015] The above steps S1 to S5 all run on the master device;

[0016] Step S6: The master device transmits the synchronization signal to each device through the selected signal transmission path to ensure that the clocks of all devices are synchronized and guarantee the timing consistency of signal decoding;

[0017] Step S7: All devices perform parallel decoding synchronously to obtain preliminary decoding results;

[0018] Step S8: Establish a dynamic multiplexing mechanism, calculate the multiplexing scores and weighting factors of each frequency point, and then adjust the preliminary decoding results based on the weighting factors to obtain the final decoding results of each device.

[0019] As a further improvement of the Bluetooth communication modulation method for multi-frequency point synchronous reception: In step S2, the instantaneous frequency calculation formula is:

[0020]

[0021] where f(t) represents the instantaneous frequency of the signal extracted at time t, and Δt is the length of the integration interval, representing the size of the time window; is the derivative of the instantaneous phase; the instantaneous phase φ(t) is extracted by performing a Hilbert transform on the preprocessed signal.

[0022] As a further improvement of the Bluetooth communication modulation method for multi-frequency point synchronous reception: In step S3, the frequency locking calculation formula is:

[0023]

[0024] where f lock (t) represents the locked frequency data; f base (t) is the reference frequency, which is the known reference frequency of the device; f expected is the desired frequency, which is the preset target frequency or optimal frequency value of the device; γ is a coefficient that controls the frequency adjustment rate and is set to a positive value; e -γ(t-τ) is used to simulate the dynamic characteristics during the frequency adjustment process; τ is the time delay at which the adjustment starts.

[0025] As a further improvement of the Bluetooth communication modulation method for multi-frequency point synchronous reception, in step S4, the priority p of the i-th frequency pointi The calculation method is as follows:

[0026]

[0027] Among them, S i is the signal strength of the i-th frequency point; N i is the noise level of the i-th frequency point; α is the exponent of the signal strength and noise ratio, which is set as a positive number; cos(f lock (t)) is an adjustment term for the i-th frequency point to be adjusted according to the change of the locked frequency data, indicating the influence of frequency fluctuation on the frequency point priority; β is the frequency correlation coefficient, which is used to control the influence degree of frequency locking on the priority.

[0028] As a further improvement of the Bluetooth communication modulation method for multi-frequency point synchronous reception: in step S5, all optional paths are traversed, and the path refers to the combination of devices passed from the source device to the target device; for each path, the optimized frequency point priority Δp i of all frequency points on it is calculated respectively; based on the optimized frequency point priority Δp i of each frequency point, the total gain G of this path is calculated respectively, and then the path with the largest gain is selected as the signal transmission path.

[0029] As a further improvement of the Bluetooth communication modulation method for multi-frequency point synchronous reception: in step S5, the calculation formula of the optimized frequency point priority Δp i of the i-th frequency point is as follows:

[0030]

[0031] Among them, m is the number of devices on the current path; S j,i and N j,i are respectively the signal strength and noise level of the i-th frequency point on the j-th device; is the weight coefficient of the signal strength and noise difference; is the weight coefficient of the sum of the signal and noise.

[0032] As a further improvement of the Bluetooth communication modulation method for multi-frequency point synchronous reception: in step S5, the calculation formula of the optimized signal gain of the i-th frequency point is:

[0033]

[0034] Among them, G i is the optimized signal gain, is the adjustment coefficient; S i is the signal strength of the i-th frequency point; N i is the noise level of the i-th frequency point;

[0035] Sum or average the optimized signal gains G of the current path i to obtain the total gain G of the current path, and then select the path with the maximum gain as the signal transmission path finally used.

[0036] As a further improvement to the Bluetooth communication modulation method for multi-frequency point synchronous reception: in step S6, each device calculates the difference based on the local timestamp and the global reference timestamp in the synchronization signal, and further obtains the synchronized global timestamp to implement the global time synchronization mechanism;

[0037] The calculation formula for the synchronized global timestamp is:

[0038]

[0039] where, T sync is the synchronized global timestamp; T j is the local timestamp of the device, and each device has an independent clock representing the time inside the device; T ref is the global reference timestamp in the synchronization signal, which is the target time for all devices to synchronize; f avg is the average frequency of the global clock, that is, the average locked frequency of all signal frequency points of all devices within a time window, obtained by weighted averaging based on the frequency samples within the time window, and is used to measure the current frequency central tendency and global frequency stability state of the entire system; f lock (t) represents the locked frequency data; λ is the correction coefficient, controlling the accuracy and correction speed of clock synchronization, 0 < λ < 1.

[0040] As a further improvement to the Bluetooth communication modulation method for multi-frequency point synchronous reception: in step S7, the calculation formula for the preliminary decoding result is:

[0041]

[0042] where, D j (t) represents the decoded pulse data of the j-th device, is the instantaneous frequency received and locked by the j-th device; is the optimized frequency priority of the i-th frequency point of the j-th device; n is the total number of frequency points.

[0043] As a further improvement to the Bluetooth communication modulation method for multi-frequency point synchronous reception: in step S8, the calculation method for the multiplexing score of the i-th frequency point is:

[0044]

[0045] where, C iis the multiplexing score of the i-th frequency point; δ is the control coefficient of the signal strength to noise ratio, which is set as a positive number; φ i is the phase of the i-th frequency point; S j,i and N j,i are the signal strength and noise level of the i-th frequency point on the j-th device respectively, and m is the number of devices on the currently selected signal transmission path;

[0046] The calculation method of the weighting factor of the i-th frequency point is as follows:

[0047]

[0048] Based on the weighting factor, the preliminary decoding result is adjusted to obtain the final decoding result of each device:

[0049]

[0050] Among them, is the final decoding result of the j-th device.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] 1. The present invention extracts the frequency characteristics of the signal in real time through time-frequency analysis and fast Fourier transform technology, and reflects the dynamic change of the signal frequency through instantaneous frequency calculation. Then, the frequency deviation is dynamically corrected through frequency locking technology, making the device frequency stable, avoiding the interference of environmental noise or device instability on the signal, and ensuring the stable transmission of the signal.

[0053] 2. The present invention optimizes the allocation of frequency points by calculating the priority of each frequency point. The priority calculation formula comprehensively considers the influence of signal quality and frequency fluctuation, ensures the maximum utilization of spectrum resources, and minimizes the influence of noise interference at the same time.

[0054] 3. The present invention dynamically optimizes the frequency point priority and adjusts the signal transmission path, reducing interference and signal attenuation. The optimized transmission path ensures that the signal is transmitted with the least loss and interference, improves the spectrum utilization efficiency and decoding efficiency, and reduces the transmission delay.

[0055] 4. The present invention ensures that the clocks of all devices are consistent with the global reference clock through the global time synchronization mechanism, solves the synchronization problem caused by signal transmission delay or clock deviation, and ensures the accurate decoding and sampling of multi-device signals.

[0056] 5. The present invention uses a parallel decoding architecture, enabling the signals of multiple devices to be decoded synchronously, reducing the delay in the decoding process. The optimized decoding result is accurate, stable, and can effectively process the signals of multiple frequency points.

[0057] 6. Through the dynamic multiplexing mechanism and redundant signal elimination technology, the present invention effectively eliminates the redundant part in the signal, ensuring that there is only an effective signal within each signal transmission time slot. The stability and transmission efficiency of the signal are greatly improved, effectively solving the problems of frequency conflict and signal overlap in Bluetooth communication. Detailed implementation manner

[0058] The technical solution of the present invention will be described in detail below:

[0059] A Bluetooth communication modulation method for multi-frequency point synchronous reception, the steps include:

[0060] Step S1: Receive the signal from the transmitting device through a Bluetooth receiver and preprocess the signal.

[0061] The received signal includes Bluetooth pulse data of different frequencies and noise interference, which need to be preprocessed, such as gain adjustment, filtering, and noise reduction, to ensure that the quality of the signal is suitable for further analysis. Common filtering means include low-pass filtering, band-pass filtering, etc. Noise suppression is also required after filtering. Through these means, the noise components of the signal in the time domain and frequency domain are effectively reduced, ensuring that the signal can be accurately used for subsequent frequency extraction, locking, and optimization processes.

[0062] Step S2: Perform time-frequency analysis on the preprocessed signal to extract the instantaneous frequency at each moment.

[0063] The preprocessed signal is the time-domain waveform data s(t), which retains the amplitude, edge, and timing characteristics of the Bluetooth pulse. To further analyze its frequency characteristics and dynamic changes, perform frequency-domain structure analysis on s(t), extract its instantaneous phase φ(t) through Hilbert transform, and then perform instantaneous frequency extraction to obtain higher time-resolution frequency characteristics, reflecting the change of the signal frequency in a short time and providing an accurate data basis for subsequent processing steps. The instantaneous frequency formula is:

[0064]

[0065] where f(t) represents the instantaneous frequency of the signal extracted at time t, which is obtained by integrating the differential of the instantaneous phase φ(t) of the signal within a small time window Δt. Δt is the length of the integration interval, representing the size of the time window; is the derivative of the instantaneous phase; the instantaneous phase φ(t) is extracted by performing Hilbert transform on the preprocessed signal.

[0066] Step S3: Lock the frequency of the frequency waveform data composed of the extracted instantaneous frequencies.

[0067] The frequency locking process corrects the frequency deviation, making the frequency data gradually approach the predetermined desired frequency, and eliminating the deviation caused by environmental noise or equipment instability in the signal. Frequency locking also enables the frequency waveform data to be stable and adapt to the reference frequency and expected frequency of the equipment, maintaining the frequency stability in the face of environmental noise interference and reducing the risks of signal distortion and misdecoding.

[0068] The formula for frequency locking is:

[0069]

[0070] Where f lock (t) represents the frequency data after locking; f base (t) is the reference frequency, which is the known reference frequency of the equipment; f expected is the desired frequency, which is the target frequency or optimal frequency value preset for the equipment; γ is a coefficient controlling the frequency adjustment rate, set as a positive value; e -γ(t-τ) is used to simulate the dynamic characteristics in the frequency adjustment process; τ is the time delay when the adjustment starts.

[0071] Frequency locking can dynamically adjust the frequency to achieve stable frequency locking.

[0072] Step S4: According to the locked frequency data, combined with the signal strength data and noise data of the equipment, dynamically optimize the allocation priorities of each frequency point to obtain the priorities of each frequency point.

[0073] By considering the relationship between the locked frequency and the signal strength of the equipment, the weight of each frequency point can be obtained, thereby optimizing the allocation of frequency points. The specific formula is as follows:

[0074]

[0075] Where p i is the priority of the i-th frequency point, used for frequency point allocation decision-making; S i is the signal strength of the i-th frequency point; N i is the noise level of the i-th frequency point, which is obtained in real time through the received signal strength indication RSSI and noise estimation algorithm in the existing Bluetooth receiver; α is the exponent of the signal strength and noise ratio, which determines the influence degree of the signal strength and noise ratio on the priority, set as a positive number (usually 1 or 2); cos(f lock (t)) is the adjustment term for the i-th frequency point to be adjusted according to the change of the locked frequency data, indicating the influence of frequency fluctuation on the frequency point priority; β is the frequency correlation coefficient, used to control the influence degree of frequency locking on the priority, so as to ensure the optimization of frequency point allocation.

[0076] Based on the change of frequency data, calculating the priority of each frequency point can ensure that the priority of the signal can maximize the utilization of spectrum resources while minimizing noise interference. The above priority calculation formula is based on the ratio of signal strength to noise and further considers the impact of the frequency waveform on signal quality.

[0077] Step S5: Based on the frequency point priority, calculate the optimized frequency point priority and the optimized signal gain, and determine the signal transmission path.

[0078] Traverse all optional paths, where a path refers to a combination of devices passed from the source device to the target device; for each path, calculate the optimized frequency point priority Δp of all frequency points on it respectively i ; Based on the optimized frequency point priority Δp of each frequency point i Calculate the total gain G of this path respectively, and then select the path with the maximum gain as the signal transmission path.

[0079] According to the frequency point priority, signal strength, noise, and information of the current signal path, dynamically optimize the signal transmission path to reduce interference and signal attenuation. Signal path optimization is mainly achieved by adjusting the transmission parameters of the signal. The optimized path ensures that the signal can be transmitted with minimal loss and interference. Through the influence of the frequency point priority and the dynamic adjustment of the signal path, the optimized path can ensure the improvement of transmission quality and communication efficiency.

[0080] The calculation of the optimized frequency point priority Δp i is as follows:

[0081]

[0082] where Δp i represents the optimized frequency point priority for optimizing the signal path; m is the number of devices on the current path; S j,i and N j,i are the signal strength and noise level of the i-th frequency point on the j-th device respectively, which are obtained in real time through the received signal strength indication RSSI and the noise estimation algorithm in the Bluetooth receiver; is the weight coefficient of the signal strength and noise difference, which affects the result of signal path optimization; is the weight coefficient of the sum of the signal and noise, which affects the result of signal path optimization.

[0083] Through the above formula, the system can adjust the signal path according to the signal strength and noise level, thereby improving the communication quality.

[0084] Furthermore, based on the optimized frequency point priorities, calculate the optimized signal gain to help determine the optimal state of the signal path. The calculation of the optimized signal gain should be weighted according to the signal strength and the optimized frequency point priorities, and preferentially select those paths with higher priorities and lower noise.

[0085] Calculate the optimized signal gain of the i-th frequency point through the following formula:

[0086]

[0087] where G i is the optimized signal gain, is the adjustment coefficient. Through gain adjustment, ensure that each path is optimized under the dual effects of signal strength and priority.

[0088] Sum or average the weighted values of all the optimized signal gains G i of the current path as the total gain G of the current path, and then select the path with the maximum gain (i.e., the path with the best signal quality) as the signal transmission path finally used.

[0089] The above steps S1 to S5 all run on the master device.

[0090] Step S6, the master device transmits the synchronization signal to each device through the selected signal transmission path to ensure that the clocks of all devices are synchronized and guarantee the timing consistency of signal decoding.

[0091] Transmit the synchronization signal to each device through the selected signal transmission path. The selection of the transmission path directly affects the transmission quality of the synchronization signal. If the gain of the transmission path is low, it may cause signal transmission delay or loss. At this time, the global time synchronization mechanism needs to adjust the time of each device to ensure that the clock of each device is consistent with the global clock. Through the global time synchronization mechanism, it can be ensured that the clocks of all devices are synchronized with the global reference time, and multiple devices decode the pulse signal in parallel to reduce delay.

[0092] Each device calculates the difference based on the local timestamp and the global reference timestamp in the synchronization signal, and further obtains the synchronized global timestamp to implement the global time synchronization mechanism. The calculation formula for the synchronized global timestamp is:

[0093]

[0094] where T sync is the synchronized global timestamp; T j is the local timestamp of the device. Each device has an independent clock, which represents the time inside the device; T ref is the global reference timestamp in the synchronization signal, which is the target time for all devices to synchronize; favg is the average frequency of the global clock, that is, the average locked frequency of all signal frequency points of all devices within a time window, which is obtained by weighted averaging based on the frequency samples within the time window, and is used to measure the current frequency central tendency and global frequency stability state of the entire system; f lock (t) represents the frequency data after locking; λ is a correction coefficient that controls the accuracy and correction speed of clock synchronization, and 0 < λ < 1.

[0095] Through the global time synchronization mechanism, the clocks of each device can be accurately synchronized. Through experiments, it can be known that the above method can achieve accurate decoding and sampling of the pulses of 96 electric energy meters.

[0096] By adjusting the clock deviation of each device, the time bases of all devices are also made consistent, so that the decoding of signals can be carried out synchronously. The unified global timestamp serves as the basis for synchronous decoding, ensuring the timing consistency of the data.

[0097] Step S7: All devices perform parallel decoding synchronously to obtain preliminary decoding results.

[0098] During the decoding process, through the parallel processing of signals by multiple devices, the pulse signals of each device can be decoded in the shortest time, thereby reducing system delay. The decoding process depends on the synchronization signals and frequency data of each device to ensure that all devices decode the pulse signals according to the same time base. The decoding process of the signals fuses the data of multiple devices together to form the final decoding result. The decoded pulse data is obtained through a parallel decoding architecture, which ensures that the signals of each device can be decoded simultaneously and are synchronized with each other.

[0099] The calculation formula for the preliminary decoding result is:

[0100]

[0101] where D j (t) represents the pulse data decoded by the j-th device, is the instantaneous frequency received and locked by the j-th device; is the optimized frequency point priority of the i-th frequency point of the j-th device; n is the total number of frequency points, that is, the total number of frequency points participating in the decoding process.

[0102] Each term in the formula represents the decoding result of a frequency point, and the finally decoded pulse data (preliminary decoding result) is the weighted sum of the decoding results of all frequency points.

[0103] Step S8: Establish a dynamic multiplexing mechanism, calculate the multiplexing score and weighting factor of each frequency point, and then adjust the preliminary decoding result based on the weighting factor to obtain the final decoding result of each device.

[0104] In this step, by selecting appropriate signal channels and multiplexing strategies, redundant signals can be eliminated, ensuring stable transmission and signal quality, thereby effectively avoiding frequency conflicts and signal overlaps.

[0105] Specifically, using the frequency reuse scoring metric, the signals of all frequency points are weighted and integrated, thereby eliminating redundant frequency point data with high noise and low weights, and retaining clear and stable signal components. The signals of each frequency point will be weighted according to their reuse scores in the current channel environment. The higher the reuse score of a frequency point, the higher the decoding weight it will obtain, thereby improving the overall signal quality and decoding efficiency.

[0106] The calculation method of the reuse score of the i-th frequency point is:

[0107]

[0108] where C i is the reuse score of the i-th frequency point; δ is the control coefficient of the signal strength to noise ratio, which is set as a positive number and obtained through experiments; φ i is the phase of the i-th frequency point; S j,i and N j,i are the signal strength and noise level of the i-th frequency point on the j-th device respectively, and m is the number of devices on the currently selected signal transmission path.

[0109] The higher the score value, the more suitable the current frequency point is for participating in multiplexing.

[0110] Furthermore, to ensure energy conservation during the signal weighting process and avoid abnormal offsets, the reuse scores of all frequency points are normalized to obtain the weighting factor:

[0111]

[0112] where ω i represents the weighting factor of the i-th frequency point.

[0113] Based on the weighting factor, the preliminary decoding result is adjusted to obtain the final decoding result of each device:

[0114]

[0115] where is the final decoding result of the j-th device.

[0116] The final decoding result is the signal after weighted fusion and elimination of redundancy. This step realizes the multiplexing judgment, priority evaluation and signal fusion control of the signal channel, while ensuring the transmission quality and frequency resource utilization efficiency, significantly improving the stability and accuracy of multi-device synchronous decoding.

[0117] The order of the invention embodiments is only for description and does not represent the superiority or inferiority of the embodiments. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0118] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments.

[0119] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A Bluetooth communication modulation method for multi-frequency point synchronous reception, characterized in that the steps Including: Step S1: Receive a signal from a transmitting device through a Bluetooth receiver and preprocess the signal. Step S2: Perform time-frequency analysis on the preprocessed signal and extract the instantaneous frequency at each moment. Step S3: Perform frequency locking on the frequency waveform data composed of the extracted instantaneous frequencies. Step S4: Dynamically optimize the allocation priority of each frequency point according to the locked frequency data, combined with the signal strength data and noise data of the device, to obtain the priority of each frequency point. Step S5: Based on the frequency point priority, calculate the optimized frequency point priority and the optimized signal gain, and determine the signal transmission path. The above steps S1 to S5 are all run on the master device. Step S6: The master device transmits the synchronization signal to each device through the selected signal transmission path to ensure that all device clocks are synchronized and ensure the timing consistency of signal decoding. Step S7: All devices perform parallel decoding synchronously to obtain a preliminary decoding result. Step S8: Establish a dynamic multiplexing mechanism, calculate the multiplexing score and weighting factor of each frequency point, and then adjust the preliminary decoding result based on the weighting factor to obtain the final decoding result of each device.

2. The Bluetooth communication modulation method for multi-frequency point synchronous reception according to claim 1, wherein: In step S2, the formula for the instantaneous frequency is: Among them, f(t) represents the instantaneous frequency of the signal extracted at time t, and Δt is the length of the integration interval, representing the size of the time window; is the derivative of the instantaneous phase; the instantaneous phase φ(t) is extracted by performing the Hilbert transform on the preprocessed signal.

3. The Bluetooth communication modulation method for multi-frequency point synchronous reception according to claim 2, wherein: In step S3, the formula for frequency locking is: Among them, f lock (t) represents the frequency data after locking; f base (t) is the reference frequency, which is the known reference frequency of the device; f expected is the desired frequency, which is the target frequency or the optimal frequency value preset for the device; γ is a coefficient that controls the frequency adjustment rate and is set as a positive value; e -γ(t-τ) is used to simulate the dynamic characteristics during the frequency adjustment process; τ is the time delay at the start of the adjustment.

4. The Bluetooth communication modulation method for multi-frequency point synchronous reception according to claim 3, characterized in that, In step S4, the priority p of the i-th frequency point i is calculated as follows: Among them, S i is the signal strength of the i-th frequency point; N i is the noise level of the i-th frequency point; α is the exponent of the signal strength and noise ratio, and is set as a positive number; cos(f lock (t)) is an adjustment term for the i-th frequency point to be adjusted according to the change of the locked frequency data, indicating the influence of frequency fluctuation on the frequency point priority; β is the frequency correlation coefficient, which is used to control the influence degree of frequency locking on the priority.

5. The Bluetooth communication modulation method for multi-frequency point synchronous reception according to claim 4, characterized in that: In step S5, all optional paths are traversed, where a path refers to a combination of devices through which a source device reaches a target device; for each path, the optimized frequency point priority Δp of all frequency points on it is calculated respectively i ; Based on the optimized frequency point priority Δp of each frequency point i the total gain G of this path is calculated respectively, and then the path with the largest gain is selected as the signal transmission path.

6. The Bluetooth communication modulation method for multi-frequency point synchronous reception according to claim 5, characterized in that: In step S5, the optimized frequency point priority Δp of the i-th frequency point i is calculated as follows: where m is the number of devices in the current path; S j,i and N j,i are the signal strength and noise level of the i-th frequency point on the j-th device, respectively; is the weight coefficient of the difference between the signal strength and the noise; is the weight coefficient of the sum of the signal and the noise.

7. The Bluetooth communication modulation method for multi-frequency point synchronous reception according to claim 5, wherein: In step S5, the formula for the optimized signal gain of the i-th frequency point is: Among them, G i is the optimized signal gain, is the adjustment coefficient; S i is the signal strength of the i-th frequency point; N i is the noise level of the i-th frequency point; Obtain the weighted sum or average of all the optimized signal gains G of the current path i as the total gain G of the current path, and then select the path with the maximum gain as the signal transmission path finally used.

8. The Bluetooth communication modulation method for multi-frequency point synchronous reception according to claim 1, wherein: In step S6, each device calculates the difference based on the local timestamp and the global reference timestamp in the synchronization signal, and further obtains the synchronized global timestamp to implement the global time synchronization mechanism. The formula for the synchronized global timestamp is: Among them, T sync is the global timestamp after synchronization; T j is the local timestamp of the device. Each device has an independent clock, which represents the time inside the device; T ref is the global reference timestamp in the synchronization signal, which is the target time for all device synchronizations; f avg is the average frequency of the global clock, that is, the average locked frequency of all signal frequency points of all devices within a period window, obtained by weighted averaging according to the frequency samples within the time window, and is used to measure the current frequency central tendency and global frequency stability state of the entire system; f lock f(t) represents the frequency data after locking; λ is the correction coefficient, which controls the accuracy and correction speed of clock synchronization, and 0 < λ < 1.

9. The Bluetooth communication modulation method for multi-frequency point synchronous reception according to claim 1, wherein: In step S7, the formula for the preliminary decoding result is: Among them, D j (t) represents the pulse data decoded by the j-th device, is the instantaneous frequency received and locked by the j-th device; is the optimized frequency point priority of the i-th frequency point of the j-th device; n is the total number of frequency points.

10. The Bluetooth communication modulation method for multi-frequency point synchronous reception according to claim 9, characterized in that: In step S8, the calculation method for the multiplexing score of the i-th frequency point is: Among them, C i is the multiplexing score of the i-th frequency point; δ is the control coefficient of the signal strength to noise ratio, which is set as a positive number; φ i is the phase of the i-th frequency point; S j,i and N j,i are respectively the signal strength and noise level of the i-th frequency point on the j-th device, and m is the number of devices on the currently selected signal transmission path; The calculation method for the weighting factor of the i-th frequency point is: Adjust the preliminary decoding result based on the weighting factor to obtain the final decoding result of each device: Among them, is the final decoding result of the j-th device.

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