Self-adaptive identification method of Bluetooth signal modulation mode

Abstract

The invention discloses a self-adaptive identification method for a Bluetooth signal modulation mode, which comprises the following steps of: firstly, processing a received radio frequency signal, and detecting and extracting a burst signal from the radio frequency signal by means of energy detection and the like; estimating and compensating the carrier frequency offset of the signal based on the phase characteristic of the lead code part of the burst signal to obtain a corrected signal; first-level classification of low-power-consumption Bluetooth (BLE) and classic Bluetooth (BR / EDR) type signals is realized by analyzing modulation index related characteristics of the corrected signals; second-level fine classification of BLE 1M / 2M or BR / EDR is completed on the basis of symbol period or synchronization sequence correlation, so that a specific modulation mode is identified; and according to an identification result, automatically selecting a demodulation algorithm matched with the identification result to carry out data analysis. According to the invention, the automatic and accurate identification of the modulation mode and the adaptive selection of the demodulation algorithm are realized, and the automation level, efficiency and reliability of the Bluetooth test are obviously improved.

Description

Technical Field

[0001] This invention relates to the field of wireless communication signal processing technology, and in particular to an adaptive identification method for Bluetooth signal modulation. Background Technology

[0002] With the rapid development of wireless communication technology, Bluetooth technology, with its low power consumption, low cost, and high convenience, has been widely deployed in numerous scenarios such as consumer electronics, wearable devices, automotive systems, and the Industrial Internet of Things. To ensure the stability of the RF performance and protocol consistency of Bluetooth devices, key parameters must be accurately measured using signal analyzers or dedicated testing instruments during R&D, certification, and production. In these testing processes, correct identification of the signal modulation scheme is the foundation and prerequisite for performing all advanced analysis functions such as subsequent demodulation, bit error rate analysis, and spectral characteristic evaluation. Multiple physical layer modulation schemes coexist within the Bluetooth standard architecture. For example, Gaussian Frequency Shift Keying (GFSK), π / 4 Differential Quadrature Phase Shift Keying (π / 4-DQPSK), and 8-Phase Differential Phase Shift Keying (8DPSK) are used in Classic Bluetooth (BR / EDR), while GFSK and its rate extension modes (such as 2M-PHY) are used in Bluetooth Low Energy (BLE). These modulation schemes differ significantly in symbol rate, modulation index, and spectral characteristics.

[0003] However, in real-world testing environments, especially for automated production line testing or over-the-air signal acquisition and analysis, test systems often cannot know the specific modulation type of the signal transmitted by the device under test (DUT). Currently, most mainstream Bluetooth test instruments or signal analysis systems rely on operators manually configuring modulation parameters. This operating mode has significant drawbacks: First, manual selection is inefficient and prone to errors; incorrect configuration will directly lead to demodulation failure and invalid test results, severely affecting the continuity and reliability of the testing process. Second, it requires a high level of professional experience from operators, limiting the application potential of the test system in unmanned, high-throughput automated testing platforms. Furthermore, even experienced technicians struggle to quickly and accurately determine the optimal channel conditions such as carrier frequency offset and channel fading, further increasing the uncertainty of the test. Therefore, developing a technology that can automatically, quickly, and accurately identify the modulation mode of Bluetooth signals is of significant practical importance and application value for improving testing efficiency, lowering the operational threshold, and automating the testing process. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the aforementioned existing problems, this invention is proposed. Therefore, this invention provides an adaptive identification method for Bluetooth signal modulation schemes to solve the problems mentioned in the background art.

[0006] To solve the above technical problems, the present invention provides the following technical solution: an adaptive identification method for Bluetooth signal modulation mode, comprising: The received Bluetooth radio frequency signal is processed to detect and extract burst signals; based on the phase characteristics of the preamble portion of the burst signal, the carrier frequency offset of the burst signal is estimated and compensated to obtain a frequency offset corrected signal. The frequency offset corrected signal is subjected to a first-level classification and discrimination to distinguish it as a low-power Bluetooth type signal or a classic Bluetooth type signal; Based on the results of the first-level classification and discrimination, the signal is further classified and discriminated at the second level to identify the specific modulation method; Based on the specific modulation scheme identified in the second-level classification, a matching demodulation algorithm is selected.

[0007] As a preferred embodiment of the adaptive identification method for Bluetooth signal modulation schemes described in this invention, the step of detecting and extracting burst signals includes: The signal energy of the Bluetooth radio frequency signal is calculated using a sliding window. When the signal energy continuously exceeds a first preset threshold, it is determined to be the start of a burst signal; When the signal energy remains below the second preset threshold, it is determined that the burst signal has ended; The signal data between the start and end of the burst signal is extracted as the burst signal.

[0008] As a preferred embodiment of the adaptive identification method for Bluetooth signal modulation schemes described in this invention, the step of estimating and compensating for the carrier frequency offset of the burst signal includes: Calculate the average phase difference of the preamble portion of the burst signal among multiple sampling points, and use the average phase difference as an estimate of the carrier frequency offset; Based on the estimated value of the carrier frequency offset, a set of phase compensation values ​​is generated; The frequency offset corrected signal is obtained by multiplying each sampling point of the burst signal with the corresponding phase compensation value.

[0009] As a preferred embodiment of the adaptive identification method for Bluetooth signal modulation schemes described in this invention, the first-level classification and discrimination step includes: Calculate the instantaneous phase difference of the frequency offset corrected signal and extract multiple phase difference peak values; Based on the statistical characteristics of the multiple phase difference peaks, a characteristic parameter related to the modulation index is determined; The characteristic parameters are compared with a preset modulation index threshold to distinguish whether the signal is a BLE type signal or a BR / EDR type signal.

[0010] In a preferred embodiment of the adaptive identification method for Bluetooth signal modulation schemes described in this invention, the second-level classification and discrimination step includes: When the first-level classification result is a BLE type signal, the symbol period of the signal is determined by measuring the time interval between multiple peaks of the instantaneous phase difference. The signal is identified as either BLE 1M modulation or BLE 2M modulation based on the symbol period.

[0011] As a preferred embodiment of the adaptive identification method for Bluetooth signal modulation schemes described in this invention, the second-level classification and discrimination step further includes: When the first-level classification result is a BR / EDR type signal, the synchronization sequence region of the data payload portion is located in the frequency offset corrected signal; The signal in the synchronization sequence region is correlated with a locally generated standard EDR synchronization sequence. Based on the results of the relevant calculations, the signal is identified as either BR modulation or EDR modulation.

[0012] As a preferred embodiment of the adaptive identification method for Bluetooth signal modulation schemes described in this invention, the step of identification based on the result of the correlation calculation includes: Obtain the maximum correlation peak value in the correlation calculation results; Determine whether the maximum correlation peak value exceeds a preset correlation threshold; If the threshold is exceeded, the signal will be identified as EDR modulation; if the threshold is not exceeded, the signal will be identified as BR modulation.

[0013] As a preferred embodiment of the adaptive identification method for Bluetooth signal modulation schemes described in this invention, the step of selecting a matching demodulation algorithm includes: If the modulation mode is identified as BLE 1M or BLE 2M, the Gaussian frequency shift keying demodulator is invoked. If it is identified as BR modulation, then a Gaussian frequency shift keying demodulator suitable for the base rate is invoked; If the modulation mode is identified as EDR, the differential phase shift keying demodulator is invoked.

[0014] Furthermore, the present invention also provides the following solution: an adaptive identification system for Bluetooth signal modulation, comprising: The burst detection module is used to process the received Bluetooth radio frequency signals, detect and extract burst signals from them; The frequency offset compensation module is used to estimate and compensate for the carrier frequency offset of the burst signal based on the phase characteristics of the preamble part of the burst signal, so as to obtain the frequency offset corrected signal. The classification and discrimination module is used to perform first-level and second-level classification and discrimination on the frequency offset corrected signal to identify the specific modulation mode; The demodulation selection module is used to select a matching demodulation algorithm based on the specific modulation scheme identified by the classification and discrimination module.

[0015] As a preferred embodiment of the adaptive identification system for Bluetooth signal modulation methods described in this invention, the classification and discrimination module is specifically used for: By analyzing the peak phase difference characteristics of the frequency offset corrected signal, the first-level classification of BLE type signals and BR / EDR type signals is completed; When the signal is of type BLE, the second-level classification of BLE 1M and BLE 2M is completed by analyzing the symbol period; When the signal is of type BR / EDR, the second-level classification of BR and EDR is completed by performing correlation operations with the standard EDR synchronization sequence.

[0016] Compared with existing technologies, the beneficial effects of this solution are: 1. This invention, through multi-level analysis and discrimination of received signals, can automatically identify various Bluetooth modulation methods without requiring manual configuration or prior knowledge from operators. It fundamentally avoids test failures caused by human error in selection, greatly improving the automation level of the testing system and its versatility for different devices under test.

[0017] 2. This invention preprocesses the signal through burst detection and frequency offset compensation, effectively overcoming interference from non-ideal factors such as noise and carrier frequency offset. Subsequently, it employs a step-by-step discrimination based on multiple physical layer features such as modulation index, symbol period, and synchronization sequence, ensuring high-precision modulation mode identification even in complex signal environments.

[0018] 3. This invention can accurately and automatically call the matching demodulation algorithm based on the recognition result, achieving a seamless connection from signal recognition to data parsing. It avoids ineffective attempts among multiple demodulation algorithms, reduces redundant system calculations, significantly improves overall processing efficiency, and thus effectively shortens the research, development, debugging, and production testing time of Bluetooth devices. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a flowchart illustrating the overall architecture of an adaptive identification method for Bluetooth signal modulation scheme according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the burst detection and effective signal interception process of the adaptive identification method for Bluetooth signal modulation mode according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the BR / EDR and BLE preamble of the adaptive identification method for Bluetooth signal modulation scheme according to an embodiment of the present invention; Figure 4 This is a time-domain variation diagram of the GFSK transmission frequency of the adaptive identification method for Bluetooth signal modulation scheme according to an embodiment of the present invention; Figure 5 This is a BR / EDR frame structure diagram of the adaptive identification method for Bluetooth signal modulation scheme according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the EDR DPSK synchronization sequence region of the adaptive identification method for Bluetooth signal modulation scheme according to an embodiment of the present invention. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0023] This invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0024] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Example 1 refer to Figures 1 to 6 This embodiment provides an adaptive identification method for Bluetooth signal modulation modes. For example... Figure 1 As shown, the method of the present invention is a multi-level processing flow, which aims to automatically identify the specific modulation mode of the received Bluetooth signal and call the corresponding demodulation algorithm without human intervention.

[0027] Furthermore, the detection of sudden signals, such as Figure 2As shown, this step aims to accurately detect and extract Bluetooth burst signal segments containing valid information from continuous digital intermediate frequency or baseband sampling data.

[0028] Specifically, firstly, energy calculation is performed on the input Bluetooth radio frequency signal sample. In this embodiment, a sliding window energy detection method is used. This is achieved by setting a window with a length of... A sliding window is used to calculate the signal energy within the window. The calculation method is as follows: in, For each input Bluetooth radio frequency signal sample, This is the starting point of the sliding window. This is the endpoint of the sliding window.

[0029] Then, the calculated sliding window energy is compared with two preset energy thresholds. When the signal energy within the window exceeds a higher first preset threshold for a continuous period of time, it is determined as the start of a burst signal. Subsequently, when the signal energy within the window remains below a lower second preset threshold for a continuous period of time, it is determined as the end of the burst signal. By determining the start and end boundaries of the burst, complete burst signal data can be extracted from the original data stream for subsequent processing.

[0030] Furthermore, due to differences in crystal oscillators at the transmitting and receiving ends and the Doppler effect, the received signal will exhibit a carrier frequency offset (CFO), which will severely affect subsequent phase-based discrimination. Therefore, it is necessary to utilize the characteristics of the Bluetooth signal preamble for a rough estimation and compensation of the frequency offset. Figure 3 As shown, whether it's BR / EDR or BLE, the preamble consists of alternating "1010..." sequences, which manifests as a linear rotation of the signal phase after Gaussian Frequency Shift Keying (GFSK) modulation. Theoretically, in the absence of frequency offset, the average phase difference of the preamble portion should be zero.

[0031] Specifically, the instantaneous frequency of each sampling point in the preamble section is calculated, where the instantaneous frequency can be obtained by calculating the phase difference between adjacent sampling points. Then, all the instantaneous frequency values ​​calculated in the preamble region are accumulated and averaged to obtain an estimate of the carrier frequency offset. : in, , It is the instantaneous frequency, representing the offset of the received Bluetooth signal relative to its nominal center frequency, and is measured in Hertz (Hz). It is the change in phase angle measured between two consecutive sampling points, and the unit is radians. It is the random frequency of the sampling points, which represents the number of times the signal processing system samples the original analog signal per second, and the unit is Hertz (Hz). It is the time index of the sampling point. This is the number of preamble sampling points used for estimation.

[0032] Furthermore, after obtaining the frequency offset estimate, a set of phase compensation sequences is generated based on the estimate, and the original burst signal is multiplied point by point to complete the frequency offset correction.

[0033] Specifically, the frequency offset compensation value for each sampling point is calculated based on the frequency offset error: in, The k-th compensation coefficient is a complex sequence. Each compensation coefficient corresponds to a sampling point in the original signal. It should be explained that this sequence constitutes a digital oscillator signal, the frequency of which is equal in magnitude and opposite in direction to the frequency offset to be compensated. The imaginary unit, i.e. .

[0034] It should be noted that when the original signal (containing (frequency offset) and the generated compensation coefficient (its frequency is) When multiplying point by point in the time domain, according to the properties of the Fourier transform, it is equivalent to performing convolution in the frequency domain, and the final effect is to shift the spectrum of the original signal. Thus The frequency offset correction returns to zero, meaning that when a complex sequence is multiplied by the original signal, the frequency offset in the original signal can be canceled out.

[0035] Then, each sampling point is multiplied by the compensation value to obtain the frequency offset compensation result. : It should be noted that after compensation, the impact of carrier frequency offset on subsequent discrimination is significantly reduced.

[0036] Furthermore, by utilizing the inherent differences between BLE and BR / EDR in the GFSK modulation index, a preliminary classification of the frequency offset-corrected signals is performed. For example... Figure 4 As shown, the instantaneous frequency change of the GFSK signal is related to the baseband data, and the instantaneous frequency is proportional to the instantaneous phase difference. According to the Bluetooth protocol, the modulation index of BLE is approximately 0.5, while the modulation index of BR / EDR is approximately 0.32. Based on this, the relationship between the modulation index and the modulation frequency can be expressed as: in, Symbol rate, This is the modulation frequency.

[0037] Furthermore, the modulation index of the signal is estimated through reverse calculation. First, the instantaneous phase difference of the corrected signal is calculated, and multiple phase difference peaks are extracted. Then, these phase difference peaks are converted into frequency peaks. Using the known Bluetooth symbol rate (1 Msps can be temporarily used as a reference), the modulation index is estimated as a characteristic parameter. Finally, the estimated modulation index is compared with a preset modulation index threshold (this threshold value is between 0.32 and 0.5, for example, 0.4). If the estimated modulation index is greater than the threshold, the signal is determined to be a BLE type signal. If the estimated modulation index is less than or equal to the threshold, the signal is determined to be a BR / EDR type signal.

[0038] Furthermore, when the first-level discrimination result is a BLE type signal, BLE1M and BLE2M are distinguished by analyzing their symbol rates. The symbol rate of BLE1M is 1 Msps (symbol period is approximately 1 μs), while the symbol rate of BLE2M is 2 Msps (symbol period is approximately 0.5 μs). Since the preamble is a "1010..." sequence, its instantaneous phase difference will exhibit periodic fluctuations, and the period of these fluctuations is the symbol period.

[0039] Furthermore, the symbol period of the signal is determined by measuring the time interval between adjacent peaks in the instantaneous phase difference sequence. If the measured symbol period is approximately 1 μs, the signal is identified as BLE 1M modulation. If the measured symbol period is approximately 0.5 μs, the signal is identified as BLE 2M modulation.

[0040] Specifically, and Let be the index symbols of the sampling points where two consecutive peaks in the instantaneous phase difference sequence are located, and let be the symbol period. It can be expressed by the following formula: Specifically, when the first-level discrimination result is a BR / EDR type signal, the unique frame structure of the EDR signal is used for differentiation. For example... Figure 5 As shown, the entire packet of the BR signal (including the payload PAYLOAD) is modulated using GFSK. The EDR signal, however, includes a DPSK modulated payload (EDR PAYLOAD) after its header, and preceded by a specific DPSK synchronization sequence (SYNC), as shown below. Figure 6 As shown.

[0041] Furthermore, within the frequency offset corrected signal, regions where EDR synchronization sequences may exist are located based on the Bluetooth frame structure. Then, a local standard EDR synchronization sequence reference signal is generated. The data from this region of the received signal is compared with the local reference sequence. Perform relevant calculations to obtain a relevant result value with an offset of m. : Where m is the estimated starting position and n is the starting position.

[0042] In addition, to eliminate the influence of signal energy variations, the relevant result values ​​were adjusted. Normalization is performed.

[0043] Specifically, after normalization, the maximum correlation peak among all cross values ​​is found and compared with a preset correlation threshold. If the maximum correlation peak is greater than the threshold, it indicates that the signal contains components that highly match the EDR synchronization sequence, and the signal is identified as EDR modulation. If the maximum correlation peak is less than or equal to the threshold, the signal is considered not to contain EDR features and is identified as BR modulation.

[0044] Furthermore, after completing all the above discriminations and identifying the specific modulation method, the system automatically calls the matching demodulation algorithm based on the identification result to perform subsequent data analysis.

[0045] Specifically, if the identification result is BLE 1M or BLE 2M, a Gaussian Frequency Shift Keying (GFSK) demodulator is invoked. If the identification result is BR, a GFSK demodulator suitable for the basic rate is invoked. If the identification result is EDR, a Differential Phase Shift Keying (DPSK) demodulator is invoked.

[0046] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0047] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0048] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0049] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0050] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0051] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An adaptive identification method for Bluetooth signal modulation, characterized in that, include: The received Bluetooth radio frequency signal is processed to detect and extract burst signals; based on the phase characteristics of the preamble portion of the burst signal, the carrier frequency offset of the burst signal is estimated and compensated to obtain a frequency offset corrected signal. The frequency offset corrected signal is classified and judged at the first level to distinguish whether it is a low power Bluetooth type signal or a classic Bluetooth type signal; Based on the results of the first-level classification and discrimination, the signal is further classified and discriminated at the second level to identify the specific modulation method; Based on the specific modulation scheme identified in the second-level classification, a matching demodulation algorithm is selected.

2. The adaptive identification method for Bluetooth signal modulation as described in claim 1, characterized in that, The step of detecting and extracting burst signals includes: The signal energy of the Bluetooth radio frequency signal is calculated using a sliding window. When the signal energy continuously exceeds a first preset threshold, it is determined to be the start of a burst signal; When the signal energy remains below the second preset threshold, it is determined that the burst signal has ended; The signal data between the start and end of the burst signal is extracted as the burst signal.

3. The adaptive identification method for Bluetooth signal modulation as described in claim 1, characterized in that, The step of estimating and compensating for the carrier frequency offset of the burst signal includes: Calculate the average phase difference of the preamble portion of the burst signal among multiple sampling points, and use the average phase difference as an estimate of the carrier frequency offset; Based on the estimated value of the carrier frequency offset, a set of phase compensation values ​​is generated; The frequency offset corrected signal is obtained by multiplying each sampling point of the burst signal with the corresponding phase compensation value.

4. The adaptive identification method for Bluetooth signal modulation as described in claim 1, characterized in that, The steps of the first-level classification and discrimination include: Calculate the instantaneous phase difference of the frequency offset corrected signal and extract multiple phase difference peak values; Based on the statistical characteristics of the multiple phase difference peaks, a characteristic parameter related to the modulation index is determined; The characteristic parameters are compared with a preset modulation index threshold to distinguish whether the signal is a BLE type signal or a BR / EDR type signal.

5. The adaptive identification method for Bluetooth signal modulation as described in claim 4, characterized in that, The steps for the second-level classification and discrimination include: When the first-level classification result is a BLE type signal, the symbol period of the signal is determined by measuring the time interval between multiple peaks of the instantaneous phase difference. The signal is identified as either BLE 1M modulation or BLE 2M modulation based on the symbol period.

6. The adaptive identification method for Bluetooth signal modulation as described in claim 5, characterized in that, The second-level classification process also includes: When the first-level classification result is a BR / EDR type signal, the synchronization sequence region of the data payload portion is located in the frequency offset corrected signal; The signal in the synchronization sequence region is correlated with a locally generated standard EDR synchronization sequence. Based on the results of the relevant calculations, the signal is identified as either BR modulation or EDR modulation.

7. The adaptive identification method for Bluetooth signal modulation as described in claim 6, characterized in that, The step of identification based on the results of the relevant calculations includes: Obtain the maximum correlation peak value in the correlation calculation results; Determine whether the maximum correlation peak value exceeds a preset correlation threshold; If the threshold is exceeded, the signal will be identified as EDR modulation; if the threshold is not exceeded, the signal will be identified as BR modulation.

8. The adaptive identification method for Bluetooth signal modulation as described in claim 7, characterized in that, The step of selecting a matching demodulation algorithm includes: If the modulation mode is identified as BLE 1M or BLE 2M, the Gaussian frequency shift keying demodulator is invoked. If it is identified as BR modulation, then a Gaussian frequency shift keying demodulator suitable for the base rate is invoked; If the modulation mode is identified as EDR, the differential phase shift keying demodulator is invoked.

9. An adaptive identification system for Bluetooth signal modulation, characterized in that, include: The burst detection module is used to process the received Bluetooth radio frequency signals, detect and extract burst signals from them; The frequency offset compensation module is used to estimate and compensate for the carrier frequency offset of the burst signal based on the phase characteristics of the preamble part of the burst signal, so as to obtain the frequency offset corrected signal. The classification and discrimination module is used to perform first-level and second-level classification and discrimination on the frequency offset corrected signal to identify the specific modulation mode; The demodulation selection module is used to select a matching demodulation algorithm based on the specific modulation scheme identified by the classification and discrimination module.

10. The adaptive identification system for Bluetooth signal modulation as described in claim 9, characterized in that, The classification and discrimination module is specifically used for: By analyzing the peak phase difference characteristics of the frequency offset corrected signal, the first-level classification of BLE type signals and BR / EDR type signals is completed; When the signal is of type BLE, the second-level classification of BLE 1M and BLE 2M is completed by analyzing the symbol period; When the signal is of type BR / EDR, the second-level classification of BR and EDR is completed by performing correlation operations with the standard EDR synchronization sequence.

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