Bluetooth GFSK signal demodulation method, device, system and electronic equipment thereof

Abstract

The embodiments of the present invention disclose a demodulation method, device, system, and electronic device for Bluetooth GFSK signals. The method includes: performing differential phase detection on the signal phase and the noise phase to obtain a plurality of differential phase signals; selecting a plurality of differential phase signals and combining them with a noise differential combined signal to obtain a combined differential signal; normalizing the coefficients of a Gaussian filter function to obtain a Gaussian discrete function; obtaining a feedforward filter function and a feedback filter function based on the Gaussian discrete function; performing a convolution operation on the feedforward filter function and the combined differential signal to obtain a first convolution value, and performing a convolution operation on the feedback filter function and the signal phase at a previous moment to obtain a second convolution value; subtracting the second convolution value from the first convolution value to obtain a decision signal; and determining the phase sign of the GFSK signal based on the sign of the decision signal. Through the above-mentioned method, the embodiments of the present invention can improve the demodulation sensitivity of the GFSK signal without increasing the computational complexity.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of Bluetooth communications, and in particular to a demodulation method, device, system and electronic equipment thereof for Bluetooth GFSK signals. Background Art

[0002] Bluetooth BR communication uses GFSK baseband modulation and demodulation. Common low-complexity demodulation methods include differential phase detection, zero-crossing detection, and frequency detection. While their performance is average, they are robust to frequency offsets. Maximum likelihood algorithms, such as the Viterbi demodulation algorithm, are theoretically optimal for receivers. However, the computational complexity increases exponentially, hardware implementation is difficult, and frequency offset immunity is poor.

[0003] GFSK demodulation is a key technology in digital communication systems based on GFSK modulation. Its performance and structure determine the receiver sensitivity and the complexity of its digital integrated circuit implementation. Traditional differential demodulation methods have relatively low complexity, but their reception performance is relatively poor. Based on this, Sukkyun Hong et al. designed a decision feedback differential demodulation method, which improves reception performance by 0.5 dB compared to differential demodulation. He Jinjin et al. designed a non-coherent maximum likelihood demodulation method that significantly improves receiver performance; however, the demodulation process requires iterative calculations, and the choice of the iteration factor affects demodulation performance.

[0004] Secondly, Bluetooth GFSK modulation uses a Gaussian filter, which introduces inter-symbol interference. Therefore, the receiver can consider using samples of the previous and next demodulated symbols to compensate for this during demodulation, improving receiver sensitivity without increasing algorithm complexity. Differential phase demodulation takes the difference between the previous and next phase sampling points. Multiple phase differences can be taken at different intervals, and then combined to improve the signal-to-noise ratio (SNR) of the differential phase, enhancing demodulation performance. Summary of the Invention

[0005] To solve the above technical problems, a technical solution adopted in an embodiment of the present invention is: providing a demodulation method for a Bluetooth GFSK signal, comprising: performing differential phase detection on a signal phase and a noise phase according to sampling points at different times to obtain a plurality of differential phase signals, wherein the differential phase signals include a signal differential phase signal and a noise differential phase signal; selecting the plurality of differential phase signals and combining them with a noise differential combined signal according to a Bluetooth data transmission rate to obtain a combined differential signal; normalizing the coefficients of a Gaussian filter function, sampling according to a symbol period with a maximum value of the coefficient as a center to obtain the Gaussian discrete function; obtaining a feedforward filter function and a feedback filter function according to the Gaussian discrete function; performing a convolution operation on the feedforward filter function and the combined differential signal based on the decision feedback principle to obtain a first convolution value, and performing a convolution operation on the feedback filter function with the signal phase at a previous time to obtain a second convolution value; subtracting the second convolution value from the first convolution value to obtain a decision signal; and determining the phase sign of the GFSK signal according to the sign of the decision signal.

[0006] In some embodiments, before performing differential phase detection on the signal phase and the noise phase according to sampling points at different times to obtain a plurality of differential phase signals, the method further includes: extracting the phase of the GFSK signal, where the phase includes the signal phase and the noise phase.

[0007] In some embodiments, performing differential phase detection on the signal phase and the noise phase according to sampling points at different times to obtain a plurality of differential phase signals includes: calculating a first differential phase signal using the following formula:

[0008]

[0009] Where Δθ 10 is the first differential phase signal, is the signal phase at the first moment, is the signal phase at the second moment, x(n-1) is the noise phase at the first moment, x(n-11) is the noise phase at the second moment, is the first signal differential phase signal, Δx 10 is the first noise differential phase signal; the second differential phase signal is calculated using the following formula:

[0010]

[0011] Wherein, Δθ5 is the second differential phase signal, is the signal phase at the third moment, is the signal phase at the fourth moment, x(n-3) is the noise phase at the third moment, x(n-8) is the noise phase at the fourth moment, is the second signal differential phase signal, Δx5 is the second noise differential phase signal; the first differential phase signal is calculated using the following formula:

[0012]

[0013] Wherein, Δθ1 is the third differential phase signal, is the signal phase at the fifth moment, is the signal phase at the sixth moment, x(n-5) is the noise phase at the fifth moment, and x(n-6) is the noise phase at the sixth moment. is the third signal differential phase signal, and Δx1 is the third noise differential phase signal.

[0014] In some embodiments, selecting the plurality of differential phase signals and the noise differential combined signal to be combined according to the Bluetooth data transmission rate to obtain a combined differential signal includes: if the Bluetooth data transmission rate is 1 Mbit / s, obtaining the combined differential signal by calculating according to the following formula:

[0015] Δθ=Δθ 10 +Δθ5+Δθ1+Δx,

[0016] Wherein, Δθ is the combined differential signal, and Δx is the noise differential combined signal; if the Bluetooth data transmission rate is 2 Mbit / s, the combined differential signal is obtained by calculating according to the following formula:

[0017] Δθ=Δθ5+Δθ1+Δx。

[0018] In some embodiments, the noise differential combined signal is obtained by calculating the following formula:

[0019] Δx=Δx 10 +Δx5+Δx1.

[0020] In some embodiments, the Gaussian discrete function is:

[0021] g(z)=-0.0315+z -1 +0.0315z -2 ;

[0022] The feedforward filter function is:

[0023] ff(z)=-0.001+0.0315z -1 -0.999z -2 -0.0315z -3 ;

[0024] The feedback filter function is:

[0025] fb(z)=-0,0315+z -1 +0.0315z -2 .

[0026] In some embodiments, the decision signal is obtained by calculating according to the following formula:

[0027] θ n =conv(ff(z),Δθ)-conv(fb(z),x(n-1)),

[0028] Among them, conv(ff(z), Δθ) is the first convolution value, conv(fb(z), x(n-1)) is the second convolution value, and x(n-1) is the signal phase at the previous moment.

[0029] In some embodiments, the phase sign of the GFSK signal is determined according to the following formula: X(n)=sign(θ n ),

[0030] Wherein, X(n) is the decision value of x(n).

[0031] In order to solve the above technical problems, another technical solution adopted in the embodiment of the present invention is: providing a demodulation device for a Bluetooth GFSK signal, comprising: a phase extraction module for extracting the phase of the GFSK signal, wherein the phase includes a signal phase and a noise phase; a differential phase detection module for performing differential phase detection on the signal phase and the noise phase according to sampling points at different times to obtain a plurality of differential phase signals, wherein the differential phase signals include a signal differential phase signal and a noise differential phase signal; a signal merging module for selecting the plurality of differential phase signals and the noise differential merging signal to merge according to the Bluetooth data transmission rate to obtain a merged differential signal; a first function module for performing a Gaussian filter function The coefficients are normalized, and sampling is performed according to the symbol period with the maximum value of the coefficient as the center to obtain the Gaussian discrete function; a second function module is used to obtain a feedforward filter function and a feedback filter function according to the Gaussian discrete function; a convolution calculation module is used to convolve the feedforward filter function with the combined differential signal based on the decision feedback principle to obtain a first convolution value, and convolve the feedback filter function with the signal phase at the previous moment to obtain a second convolution value; a difference calculation module is used to subtract the second convolution value from the first convolution value to obtain a decision signal; a symbol decision module is used to decide the phase sign of the Bluetooth GFSK signal according to the sign of the decision signal.

[0032] In order to solve the above technical problems, another technical solution adopted in the embodiment of the present invention is: providing a demodulation system for a Bluetooth GFSK signal, comprising: a signal unit and a decision unit, wherein the signal unit comprises a first differential phase detector, a second differential phase detector, a third differential phase detector, a first merging circuit, a second merging circuit and a selection circuit, the first differential phase detector, the second differential phase detector and the third differential phase detector are all used to receive the signal phase, the first differential phase detector and the second differential phase detector are respectively used to output the second differential phase signal Δθ5 and the first differential phase signal Δθ1 after differential phase detection to the first merging circuit, and the third differential phase detector is used to output the third differential phase signal Δθ5 after differential phase detection to the first merging circuit. 10 Output to the second merging circuit; the first merging circuit is used to merge the first differential phase signal and the second differential phase signal, and output the first merged differential signal to the selection circuit and the second merging circuit; the second merging circuit is used to merge the first merged differential signal, the third differential phase signal and the sum, and output the second merged differential signal to the selection circuit; the selection circuit is used to output the first merged differential signal to the decision unit when the Bluetooth output transmission rate is 2Mbit / s; or output the second merged differential signal to the decision unit when the Bluetooth output transmission rate is 2Mbit / s; the decision unit includes a feedforward filter, an operation circuit, a decision device and a feedback filter, and the decision unit is used to calculate a decision symbol based on the merged differential signal, and decide the phase symbol of the Bluetooth GFSK signal based on the decision symbol.

[0033] To solve the above technical problems, another technical solution adopted in the embodiment of the present invention is: to provide an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the above-mentioned demodulation method of a Bluetooth GFSK signal.

[0034] To solve the above technical problems, another technical solution adopted in the embodiment of the present invention is: providing a non-volatile computer storage medium, wherein the computer storage medium stores computer-executable instructions, and the computer-executable instructions are executed by one or more processors, so that the one or more processors can execute the above-mentioned Bluetooth GFSK signal demodulation method.

[0035] The beneficial effect of the embodiments of the present invention is that, unlike the prior art, the embodiments of the present invention can improve the demodulation sensitivity of the GFSK signal without increasing the computational complexity through the above-mentioned method. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 1 is a schematic structural diagram of a Bluetooth GFSK signal demodulation system provided by an embodiment of the present invention;

[0037] Figure 2 is a structural diagram of a signal unit provided by an embodiment of the present invention;

[0038] Figure 3 This is a schematic structural diagram of a judgment unit provided by an embodiment of the present invention;

[0039] Figure 4 1 is a flow chart of a method for demodulating a Bluetooth GFSK signal provided by an embodiment of the present invention;

[0040] Figure 5 1 is a schematic structural diagram of a Bluetooth GFSK signal demodulation device provided in an embodiment of the present invention;

[0041] Figure 6 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0043] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0044] GFSK technology is based on FSK. Before the original digital signal is transmitted after FSK modulation, a Gaussian low-pass filter is applied to limit the spectral width of the modulated signal, thereby limiting the transmission spectrum and power consumption in communications. GFSK Gaussian frequency shift keying modulation is a digital modulation method that pre-modulates and filters the input data through a Gaussian low-pass filter before performing FSK modulation. Unlike conventional frequency modulation, GFSK modulation passes the transmitted data symbols through a Gaussian filter; this allows for continuous transitions between the two different frequencies, thus limiting the spectral bandwidth of the modulated signal. Therefore, while maintaining a constant amplitude, the modulated signal's spectrum can be controlled by varying the 3dB bandwidth of the Gaussian low-pass filter. This results in a constant amplitude envelope, a concentrated power spectrum, and a narrow spectrum—all desirable characteristics for wireless communication systems.

[0045] In order to solve the above problems, the embodiment of the present invention provides a demodulation system for Bluetooth GFSK signals, the structural diagram of which is shown in FIG. Figure 1 As shown, it includes a signal unit 10 and a decision unit 20, wherein the signal unit 10 is used to receive the phase extracted from the Bluetooth GFSK signal, perform multi-branch differential phase detection on the phase and combine it, and output the combined differential signal to the decision unit; the decision unit 20 calculates the decision symbol according to the combined differential signal, and decides the phase symbol of the Bluetooth GFSK signal according to the decision symbol.

[0046] In some embodiments, the structural diagram of the signal unit 10 is as follows: Figure 2 As shown, the first differential phase detector 111, the second differential phase detector 112, the third differential phase detector 113, the first merging circuit 121, the second merging circuit 122 and the selection circuit 13 are included. The first differential phase detector 111, the second differential phase detector 112 and the third differential phase detector 113 are all used to receive the signal phase. The first differential phase detector 111 and the second differential phase detector 112 are respectively used to output the second differential phase signal Δθ5 and the first differential phase signal Δθ1 after differential phase detection to the first merging circuit 121. The third differential phase detector 113 is used to output the third differential phase signal Δθ5 after differential phase detection to the first merging circuit 121. 10 Output to the second merging circuit 122.

[0047] The first merging circuit 121 is used to merge the first differential phase signal and the second differential phase signal, and output the first merged differential signal to the selection circuit 13 and the second merging circuit 122; the second merging circuit 122 is used to merge the first merged differential signal, the third differential phase signal and the sum, and output the second merged differential signal to the selection circuit 13.

[0048] The selection circuit is configured to output the first combined differential signal to the decision unit 20 when the Bluetooth output transmission rate is 2 Mbit / s; or output the second combined differential signal to the decision unit 20 when the Bluetooth output transmission rate is 2 Mbit / s.

[0049] The decision unit 20 includes a feedforward filter 21, an operation circuit 22, a decision device 23 and a feedback filter 24. The decision unit is used to calculate a decision symbol according to the combined differential signal and decide the phase symbol of the Bluetooth GFSK signal according to the decision symbol.

[0050] Based on the above-mentioned Bluetooth GFSK signal demodulation system, the embodiment of the present invention further provides a Bluetooth GFSK signal demodulation method, the flow chart of the method is as follows: Figure 4 As shown, the following steps are included:

[0051] Step S100: extracting the phase of the GFSK signal.

[0052] It should be noted that the phase includes the signal phase and the noise phase.

[0053] Step S200: performing differential phase detection on the signal phase and the noise phase according to sampling points at different times to obtain a plurality of differential phase signals.

[0054] Specifically, the first differential phase signal is calculated using the following formula:

[0055]

[0056] Where Δθ 10 is the first differential phase signal, is the signal phase at the first moment, is the signal phase at the second moment, x(n-1) is the noise phase at the first moment, x(n-11) is the noise phase at the second moment, is the first signal differential phase signal, Δx 10 is the first noise differential phase signal;

[0057] The second differential phase signal is calculated using the following formula:

[0058]

[0059] Wherein, Δθ5 is the second differential phase signal, is the signal phase at the third moment, is the signal phase at the fourth moment, x(n-3) is the noise phase at the third moment, x(n-8) is the noise phase at the fourth moment, is the second signal differential phase signal, Δx5 is the second noise differential phase signal;

[0060] The first differential phase signal is calculated using the following formula:

[0061]

[0062] Wherein, Δθ1 is the third differential phase signal, is the signal phase at the fifth moment, is the signal phase at the sixth moment, x(n-5); is the noise phase at the fifth moment, x(n-6) is the noise phase at the sixth moment, is the third signal differential phase signal, and Δx1 is the third noise differential phase signal.

[0063] Step S300: According to the Bluetooth data transmission rate, select the plurality of differential phase signals and the noise differential combined signal to be combined to obtain a combined differential signal.

[0064] Specifically, if the Bluetooth data transmission rate is 1 Mbps, the combined differential signal is obtained by calculation according to the following formula:

[0065] Δθ=Δθ 10 +Δθ5+Δθ1+Δx, (4)

[0066] Wherein, Δθ is the combined differential signal, and Δx is the noise differential combined signal;

[0067] If the Bluetooth data transmission rate is 2 Mbit / s, the combined differential signal is obtained by calculating according to the following formula:

[0068] Δθ=Δθ5+Δθ1+Δx. (5)

[0069] Step S400: normalizing the coefficients of the Gaussian filter function, sampling according to the symbol period with the maximum value of the coefficient as the center, and obtaining a Gaussian discrete function.

[0070] As known from the above process, GFSK Gaussian frequency shift keying modulation is specifically a digital modulation in which the input data is pre-modulated and filtered by a Gaussian low-pass filter before being subjected to FSK modulation. Therefore, in an embodiment of the present invention, the coefficients of the Gaussian filter function are normalized, and sampling is performed according to the symbol period with the maximum value of the coefficient as the center to obtain the following Gaussian discrete function:

[0071] g(z)=-0.0315+z -1 +0.0315z -2 (6)

[0072] Step S500: Obtaining a feedforward filter function and a feedback filter function according to a Gaussian discrete function.

[0073] According to the above Gaussian discrete function, the feedforward filter function and the feedback filter function can be approximately obtained, where the feedforward filter function is:

[0074] ff(z)=-0.001+0.0315z -1 -0.999z -2 -0.0315z -3 , (7)

[0075] The feedback filter function is:

[0076] fb(z)=-0.0315+z -1 +0.0315z -2 (8)

[0077] Step S600: Based on the decision feedback principle, convolve the feedforward filter function with the combined differential signal to obtain a first convolution value, and convolve the feedback filter function with the signal phase at the previous moment to obtain a second convolution value.

[0078] Step S700: Subtract the second convolution value from the first convolution value to obtain a decision signal.

[0079] Specifically, the decision signal is obtained by calculating according to the following formula:

[0080] θ n =conv(ff(z),Δθ)-conv(fb(z),x(n-1)), (9)

[0081] Among them, conv(ff(z), Δθ) is the first convolution value, conv(fb(z), x(n-1)) is the second convolution value, and x(n-1) is the signal phase at the previous moment.

[0082] Step S800: Determine the phase sign of the GFSK signal according to the sign of the decision signal.

[0083] Specifically, the phase symbol of the GFSK signal is determined according to the following formula:

[0084] X(n)=sign(θ n ),

[0085] Wherein, X(n) is the decision value of x(n).

[0086] Different from the prior art, through the above-mentioned method, the embodiments of the present invention can improve the demodulation sensitivity of the GFSK signal without increasing the computational complexity.

[0087] Based on the above-mentioned demodulation method of Bluetooth GFSK signal, the embodiment of the present invention further provides a demodulation device for Bluetooth GFSK signal, the structural diagram of the device is shown in FIG. Figure 5 As shown, the device includes a phase extraction module 100, a differential phase detection module 200, a signal merging module 300, a first function module 400, a second function module 500, a convolution calculation module 600, a difference calculation module 700 and a symbol decision module 800, wherein,

[0088] The phase extraction module 100 is used to extract the phase of the GFSK signal, which includes the signal phase and the noise phase. The differential phase detection module 200 is used to perform differential phase detection on the signal phase and the noise phase based on sampling points at different times to obtain multiple differential phase signals, including a signal differential phase signal and a noise differential phase signal. The signal merging module 300 is used to select the multiple differential phase signals and merge them with the noise differential combined signal based on the Bluetooth data transmission rate to obtain a combined differential signal. The first function module 400 is used to normalize the coefficients of the Gaussian filter function and sample them according to the symbol period centered around the maximum value of the coefficients to obtain the Gaussian discrete function. The second function module 500 is used to obtain a feedforward filter function and a feedback filter function based on the Gaussian discrete function. The convolution calculation module 600 is used to convolve the feedforward filter function with the combined differential signal based on the decision feedback principle to obtain a first convolution value, and to convolve the feedback filter function with the signal phase at the previous time to obtain a second convolution value. The difference calculation module 700 is used to subtract the second convolution value from the first convolution value to obtain a decision signal. The symbol decision module 800 is used to decide the phase symbol of the Bluetooth GFSK signal according to the symbol of the decision signal.

[0089] Figure 6 FIG is a schematic diagram of the hardware structure of an electronic device provided by an embodiment of the present invention, such as Figure 6 As shown, the electronic device 900 includes:

[0090] One or more processors 901 and memory 902, Figure 6 A processor 901 is taken as an example.

[0091] The processor 901 and the memory 902 may be connected via a bus or other means. Figure 6 The bus connection is taken as an example.

[0092] Memory 902, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer executable programs, and modules. Processor 901 executes the non-volatile software programs, instructions, and units stored in memory 902 to perform various functional applications and data processing of the electronic device, thereby implementing the Bluetooth GFSK signal demodulation method described in the above method embodiment.

[0093] The memory 902 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and applications required for at least one function; the data storage area may store data created according to the use of the electronic device, etc. In addition, the memory 902 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 902 may optionally include a memory remotely located relative to the processor 901, and these remote memories may be connected to the electronic device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0094] The one or more units are stored in the memory 902, and when executed by the one or more processors 901, perform a demodulation method of a Bluetooth GFSK signal in any of the above method embodiments, for example, perform the above described Figure 4 Steps S100 to S800 of the method or implementation Figure 5 The functions of each module in the device shown.

[0095] The electronic device can execute a Bluetooth GFSK signal demodulation method provided by an embodiment of the present invention, and has a corresponding program module and beneficial effects for executing the method. For technical details not fully described in the electronic device embodiment, please refer to a Bluetooth GFSK signal demodulation method provided by an embodiment of the present invention.

[0096] Embodiments of the present invention also provide a non-volatile computer-readable storage medium, which may be included in the device described in the above embodiments, or may exist independently and not incorporated into the device. The non-volatile computer-readable storage medium carries one or more programs, which, when executed, implement a Bluetooth GFSK signal demodulation method according to an embodiment of the present disclosure.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for demodulating a Bluetooth GFSK signal, characterized in that: include: Performing differential phase detection on the signal phase and the noise phase according to sampling points at different times to obtain a plurality of differential phase signals, wherein the differential phase signals include a signal differential phase signal and a noise differential phase signal; According to the Bluetooth data transmission rate, select the plurality of differential phase signals and the noise differential combined signal to combine to obtain a combined differential signal; Normalizing the coefficients of the Gaussian filter function, sampling according to the symbol period with the maximum value of the coefficient as the center, and obtaining the Gaussian discrete function; Obtaining a feedforward filter function and a feedback filter function according to the Gaussian discrete function; Based on the decision feedback principle, convolving the feedforward filter function with the combined differential signal to obtain a first convolution value, and convolving the feedback filter function with the signal phase at a previous moment to obtain a second convolution value; subtracting the second convolution value from the first convolution value to obtain a decision signal; The phase sign of the GFSK signal is determined according to the sign of the determination signal.

2. The method according to claim 1, characterized in that Before performing differential phase detection on the signal phase and the noise phase according to sampling points at different times to obtain a plurality of differential phase signals, the method further includes: The phase of the GFSK signal is extracted, where the phase includes a signal phase and a noise phase.

3. The method according to claim 2, characterized in that The method of performing differential phase detection on the signal phase and the noise phase according to sampling points at different times to obtain a plurality of differential phase signals includes: The first differential phase signal is calculated using the following formula: Where Δθ 10 is the first differential phase signal, is the signal phase at the first moment, is the signal phase at the second moment, x(n-1) is the noise phase at the first moment, x(n-11) is the noise phase at the second moment, is the first signal differential phase signal, Δx 10 is the first noise differential phase signal; The second differential phase signal is calculated using the following formula: Wherein, Δθ5 is the second differential phase signal, is the signal phase at the third moment, is the signal phase at the fourth moment, x(n-3) is the noise phase at the third moment, x(n-8) is the noise phase at the fourth moment, is the second signal differential phase signal, Δx5 is the second noise differential phase signal; The third differential phase signal is calculated using the following formula: Wherein, Δθ1 is the third differential phase signal, is the signal phase at the fifth moment, is the signal phase at the sixth moment, x(n-5) is the noise phase at the fifth moment, and x(n-6) is the noise phase at the sixth moment. is the third signal differential phase signal, and Δx1 is the third noise differential phase signal.

4. The method according to claim 3, characterized in that The step of selecting, according to the Bluetooth data transmission rate, the plurality of differential phase signals and the noise differential combined signal for combination to obtain a combined differential signal comprises: If the Bluetooth data transmission rate is 1 Mbit / s, the combined differential signal is obtained by calculating according to the following formula: Δθ=Δθ 10 +Δθ5+Δθ1+Δx, Wherein, Δθ is the combined differential signal, and Δx is the noise differential combined signal; If the Bluetooth data transmission rate is 2 Mbit / s, the combined differential signal is obtained by calculating according to the following formula: Δθ=Δθ5+Δθ1+Δx。 5. The method according to claim 4, characterized in that The noise differential combined signal is obtained by the following calculation: Δx=Δx 10 +Δx5+Δx1。 6. The method according to claim 5, characterized in that The Gaussian discrete function is: g(z)=-0.0315+z -1 +0.0315z -2 ; The feedforward filter function is: ff(z)=-0.001+0.0315z -1 -0.999z -2 -0.0315z -3 ; The feedback filter function is: fb(z)=-0.0315+z -1 +0.0315z- 2 。 7. The method according to claim 6, characterized in that The decision signal is obtained by calculating according to the following formula: θ n =conv(ff(z),Δθ)-conr(fb(z),x(n-1)), Among them, conv(ff(z), Δθ) is the first convolution value, conv(fb(z), x(n-1)) is the second convolution value, and x(n-1) is the signal phase at the previous moment.

8. The method according to claim 7, characterized in that According to the following formula, the phase symbol of the GFSK signal is determined: X(n)=sign(θ n ), Wherein, X(n) is the decision value of x(n).

9. A demodulation device for Bluetooth GFSK signals, characterized in that: include: A phase extraction module, configured to extract the phase of the GFSK signal, wherein the phase includes a signal phase and a noise phase; A differential phase detection module is used to perform differential phase detection on the signal phase and the noise phase according to sampling points at different times to obtain a plurality of differential phase signals, wherein the differential phase signals include a signal differential phase signal and a noise differential phase signal; A signal merging module, configured to select and merge the plurality of differential phase signals and the noise differential combined signal according to a Bluetooth data transmission rate to obtain a combined differential signal; A first function module is used to normalize the coefficients of the Gaussian filter function, and to perform sampling according to the symbol period with the maximum value of the coefficient as the center to obtain the Gaussian discrete function; A second function module is used to obtain a feedforward filter function and a feedback filter function according to the Gaussian discrete function; a convolution calculation module, configured to perform a convolution operation on the feedforward filter function and the combined differential signal based on a decision feedback principle to obtain a first convolution value, and to perform a convolution operation on the feedback filter function and the signal phase at a previous moment to obtain a second convolution value; a difference calculation module, configured to subtract the second convolution value from the first convolution value to obtain a decision signal; The symbol decision module is used to decide the phase symbol of the Bluetooth GFSK signal according to the symbol of the decision signal.

10. A Bluetooth GFSK signal demodulation system, characterized in that: include: Signal unit and decision unit, wherein, The signal unit includes a first differential phase detector, a second differential phase detector, a third differential phase detector, a first merging circuit, a second merging circuit and a selection circuit. The first differential phase detector, the second differential phase detector and the third differential phase detector are all used to receive signal phases. The first differential phase detector and the second differential phase detector are respectively used to output the second differential phase signal Δθ5 and the first differential phase signal Δθ1 after differential phase detection to the first merging circuit. The third differential phase detector is used to output the third differential phase signal Δθ5 after differential phase detection to the first merging circuit. 10 output to the second combining circuit; The first combining circuit is used to combine the first differential phase signal and the second differential phase signal, and output a first combined differential signal to the selection circuit and the second combining circuit; The second combining circuit is used to combine the first combined differential signal and the third differential phase signal, and output a second combined differential signal to the selection circuit; The selection circuit is configured to output the first combined differential signal to the decision unit when the Bluetooth output transmission rate is 2 Mbit / s; or output the second combined differential signal to the decision unit when the Bluetooth output transmission rate is 2 Mbit / s; The decision unit includes a feedforward filter, an operation circuit, a decision device and a feedback filter. The decision unit is used to calculate a decision symbol according to the combined differential signal and decide the phase symbol of the Bluetooth GFSK signal according to the decision symbol.

11. An electronic device, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor. The instructions are executed by the at least one processor to enable the at least one processor to perform the Bluetooth GFSK signal demodulation method according to any one of claims 1 to 8.

12. A non-volatile computer storage medium, characterized in that: The computer storage medium stores computer-executable instructions, which are executed by one or more processors to enable the one or more processors to execute the Bluetooth GFSK signal demodulation method according to any one of claims 1 to 8.

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