A method for identifying the signal mode type of a Bluetooth comprehensive tester

Abstract

The present invention discloses a method for identifying signal mode types of a Bluetooth comprehensive tester, including autocorrelation calculation of a Bluetooth signal preamble, high-order cumulant parameter calculation, determination of frame rate type based on the peak-to-average ratio of the Bluetooth signal, and determination of frame rate type based on the packet type of the Bluetooth signal. By establishing a preamble database of different frame rate types of Bluetooth signals, the present invention determines the frame rate of BLE according to the autocorrelation characteristics of different preambles and considering different correlation operation values obtained at different frame rates; further differentiates BLE, BR, and EDR signals by combining the high-order cumulant characteristics of Bluetooth signals to avoid identification errors; and uses the difference between the synchronization sequence of EDR and the BR and BLE modes to calculate different peak-to-average ratios to determine and identify the EDR frame mode.

Description

Technical Field

[0001] The present invention relates to a method for identifying Bluetooth signals, specifically a method for identifying the signal mode type of a Bluetooth comprehensive tester, and belongs to the technical field of wireless communication signal processing. Background Art

[0002] With the rapid development of wireless communication technology, Bluetooth technology for short-distance high-speed transmission requirements has been widely applied in handheld communication devices such as mobile phones and laptops, as well as shared bicycles. Therefore, the testing of Bluetooth devices has become an important process for equipping Bluetooth technology into various application products.

[0003] Generally speaking, the testing of Bluetooth devices requires a high-precision Bluetooth comprehensive tester, and a high-precision Bluetooth comprehensive tester requires an efficient signal synthesis tester algorithm. Specifically, the identification of the Bluetooth signal frame rate mode is a key link in the Bluetooth comprehensive tester algorithm. The frame rates of Bluetooth signals are divided into BR, EDR2M, EDR3M, BLE1M, BLE2M, BLE125K, and BLE500K. Since there are certain differences in the frame structures of Bluetooth signals with each frame rate, it causes differences in the signal frame header parsing and payload parsing at the receiving end of the Bluetooth comprehensive tester. In addition, the accurate acquisition of Bluetooth signal frame structure information is a prerequisite for correctly parsing the frame header information, correctly demodulating Bluetooth signals, and decoding.

[0004] Since Bluetooth devices have been widely applied in all aspects of our lives, there have been a large number of previous research results on physical layer signal processing algorithms for Bluetooth signals (including also the technology for identifying Bluetooth signal frame rates). In the prior art, a Bluetooth signal processing device and a Bluetooth data frame detection method disclosed in the patent publication number CN107181540B include an energy estimator to calculate the power value of the Bluetooth signal, a frequency shift keying demodulator to demodulate the Bluetooth signal when the power value is greater than the first threshold, output a demodulated signal, and a frame detector to perform frame detection on the demodulated signal and output a frame detection signal. In this way, the Bluetooth signal is processed to ensure that demodulation is performed only when the power value of the Bluetooth signal meets the preset conditions, without performing demodulation at all times, and then only the valid Bluetooth signals that meet the power requirements are subjected to the frame detection process, reducing the time for frame detection, thereby reducing the power consumption during Bluetooth signal processing, while not affecting the normal processing of valid Bluetooth data. However, there are differences in the application environment and test requirements between the Bluetooth signal frame rate identification developed for Bluetooth comprehensive testers and the frame rate identification of traditional Bluetooth device signals, which are not mentioned and solved in the prior art. Summary of the Invention

[0005] The object of the present invention is to provide a method for identifying the signal mode type of a Bluetooth comprehensive tester to solve the technical problem that the frame rate recognition of traditional Bluetooth device signals has differences in application environments and test requirements. This identification method is specifically applied to the detection and classification technology of wireless signals at the receiving end during the development of Bluetooth comprehensive testers, and uses the characteristics of the Bluetooth signal frame structure to jointly determine and identify the frame rate type, improving the accuracy of the Bluetooth comprehensive tester in detecting device signals.

[0006] The present invention achieves the above object through the following technical solutions: A method for identifying the signal mode type of a Bluetooth comprehensive tester, which uses the characteristics of the Bluetooth signal frame structure to jointly determine and identify the frame rate type. Among them, the characteristics of the Bluetooth signal frame structure include the Bluetooth signal preamble, high-order cumulants (the differences in high-order cumulants under different modulation methods), the ratio of the correlation peak to the average value of the EDR synchronization sequence, and the packet type information carried by the frame header.

[0007] This identification method specifically includes:

[0008] Step 1: Autocorrelation calculation of the Bluetooth signal preamble:

[0009] When the Bluetooth signal is in the BR, EDR-2M, or EDR-3M mode, the preamble is 4 bits;

[0010] When the Bluetooth signal is BLE-Coded, the preamble is 80 bits;

[0011] When the Bluetooth signal is BLE-2M, the preamble is 16 bits;

[0012] When the Bluetooth signal is BLE-1M, the preamble is 8 bits;

[0013] Therefore, at the receiving end of the Bluetooth comprehensive tester, perform correlation operations on the received signal with the 80-bit preamble, 16-bit preamble, 8-bit preamble, and 4-bit preamble respectively;

[0014] Step 2: Calculation of high-order cumulant parameters:

[0015] The modulation methods of Bluetooth signals include GFSK and DPSK;

[0016] Among them, BR and BLE use GFSK modulation; the frame header part of EDR uses GFSK, and the payload part of EDR uses DPSK modulation;

[0017] Distinguish BR, EDR, and BLE through the judgment of the high-order cumulants of the modulated Bluetooth signal;

[0018] Step 3: Determine the frame rate type based on the peak-to-average ratio of the Bluetooth signal:

[0019] The judgment of EDR signal requires the use of synchronization sequence. According to the Bluetooth protocol, the synchronization sequence of EDR signal is modulated by DPSK.

[0020] Step 4: Determine the frame rate type based on the packet type of the Bluetooth signal:

[0021] The judgment of EDR-2M and EDR-3M requires the packet type detected during synchronization frame header parsing, and then further refines the distinction;

[0022] According to the Bluetooth protocol, the preamble of the frame header carries packet type information. After accurately locating the frame header of the Bluetooth signal, the preamble carrying the packet type information is found, and then the packet type is determined based on the preamble.

[0023] As a further technical solution of the present invention: Step 1 specifically includes:

[0024] The preamble of BR and EDR frame formats is represented by P BR / EDR ;

[0025] The preamble of the BLE-1M frame format is represented by P BLE1M ;

[0026] The preamble of the BLE-2M frame format is represented by P BLE2M ;

[0027] The preamble of the BLE-Coded frame format is represented by P BLE80 ;

[0028] At the receiving end of the Bluetooth tester, the received signal is represented as R(t), where t is a time variable. Then, a phase difference operation is performed on the received signal R(t) to obtain the phase difference sequence of the received signal R(t):

[0029] L(n),n=0,1,…N-1

[0030] Right now:

[0031] L(n)=Φ(R(t)),n=0,1,…N-1

[0032] Where Φ represents the phase difference operation function, and N represents the sequence length;

[0033] The phase difference sequence L(n) of the received signal is respectively BLE80 , P BLE2M and P BLE1M Do the related operations, namely:

[0034] K=Α((P BLE80 , P BLE2M , P BLE1M ), L(n))

[0035] Among them, Α is the relevant operation function and K is the relevant operation value.

[0036] As a further technical solution of the present invention: in step one, when the Bluetooth signal is BLE-Coded, BLE-Coded includes BLE125K and BLE500K. The distinction between BLE125K and BLE500K is made by using the last bit of the accessAddress after FEC decoding to represent the information carrying the distinction between BLE125K and BLE500K. When this bit is 1, it represents BLE500K, and when it is 0, it represents BLE125K.

[0037] As a further technical solution of the present invention: step two specifically includes:

[0038] For the zero-mean complex stationary random process R(t), its p-th order mixed moment can be expressed as:

[0039] M pq =E[R(t) p-q R * (t) q

[0040] Among them, * represents the conjugate of the function, and the high-order cumulant is defined as:

[0041]

[0042] The high-order cumulants of different Bluetooth signal frame rate types are different, and the Bluetooth signal frame rate type can be identified according to the differences in the high-order cumulants.

[0043] As a further technical solution of the present invention: three characteristic parameters are selected from the second-order, fourth-order, and sixth-order cumulants of the high-order cumulants for Bluetooth signal frame rate type identification, namely:

[0044]

[0045] Among them, F1 is used to judge the BR signal, F2 is used to judge the EDR signal, and F3 is used to judge the BLE signal.

[0046] As a further solution of the present invention: in step three, it specifically includes:

[0047] The synchronization sequence of EDR2M is:

[0048] syn2M=[0 0 0 1 1 1 0 1 1 1 0 1 1 1 1 1 0 1 0 1 0 1]

[0049] The synchronization sequence of EDR3M is:

[0050] ​syn3M = [0 0 0 0 1 0 1 1 1 0 1 0 1 1 1 0 1 0 1 1 1 1 1 1 0 1 0 0 1 0 01 0]

[0051] At the receiving end of the Bluetooth tester, the received signal R(t) is correlated with the synchronization sequence to obtain:

[0052] K EDR K(t) = Α((syn2M, syn3M), R(t))

[0053] First, find the correlation value K EDR The peak value of K(t) is written as K H ; Second, find the average value of the correlation values of K EDR (t), which is written as K M ; The ratio of the peak value to the average value of the correlation values is:

[0054] K peak = K H / K M

[0055] Based on K peak = K H / K M Judge whether it is an EDR signal; when K peak is greater than a certain threshold, it is considered an EDR signal, otherwise it is not an EDR signal. Among them, the value of the threshold needs to be determined according to the communication environment of the Bluetooth signal.

[0056] As a further technical solution of the present invention: Step four specifically includes:

[0057] According to the Bluetooth protocol, the preamble of the frame header has 4 bits carrying packet type information, and the 4 bits carrying packet type include NULL, POLL, FHS, DV, HV1, HV2, HV3, EV3, EV4, EV5, DM1, DH1, DM3, DH3, DM5, DH5, AUX1, 2-EV3, 2-EV5, 2-DH1, 2-DH3, 2-DH5, 3-EV3, 3-EV5, 3-DH1, 3-DH3, and 3-DH5;

[0058] When the packet type detection result is 2-EV3, 2-EV5, 2-DH1, 2-DH3, and 2-DH5, it is judged as EDR2M;

[0059] When the packet type detection result is 3-EV3, 3-EV5, 3-DH1, 3-DH3, and 3-DH5, it is judged as EDR3M;

[0060] Based on the packet type detection result, complete the judgment of the frame rate type.

[0061] The beneficial effects of the present invention are as follows: 1) By establishing a preamble database for different frame rate types of Bluetooth signals, and according to the autocorrelation characteristics of different preambles, considering different frame rates to obtain different correlation operation values, the frame rate of BLE is determined; 2) The present invention combines the high-order cumulant characteristics of Bluetooth signals to further distinguish BLE, BR, and EDR signals, avoiding recognition errors caused by the autocorrelation calculation of preambles; 3) The present invention uses the difference between the synchronization sequence of EDR and the BR and BLE modes, thereby calculating different peak-to-average ratios to determine and identify the EDR frame mode; 4) The present invention combines preambles, peak-to-average ratios, and high-order cumulants, as well as packet type determination to identify the frame rate type of Bluetooth signals. Multiple determination conditions have obvious characteristic differences and can accurately identify different Bluetooth signal frame rates; 5) The method in the present invention can have strong robustness for testing various parameters of a Bluetooth comprehensive tester in an environment with strong noise interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 is the high-order cumulant value of different Bluetooth frame rate signals of the present invention;

[0063] Figure 2 is the flow chart for identifying the Bluetooth signal frame rate of the present invention;

[0064] Figure 3 is the simulation diagram of the autocorrelation operation of the Bluetooth signal preamble of the present invention;

[0065] Figure 4 is the simulation diagram of the peak-to-average ratio calculation of the Bluetooth signal of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0066] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0067] Embodiment: As Figure 2 shown, a method for identifying the signal mode type of a Bluetooth comprehensive tester, the identification method uses the frame structure characteristics of Bluetooth signals to determine the frame rate type, wherein the frame structure characteristics of Bluetooth signals specifically include: the Bluetooth signal preamble, high-order cumulants (the difference in high-order cumulants under different modulation methods), the relevant peak-to-average ratio of the EDR synchronization sequence, and the packet type information carried by the frame header.

[0068] The identification method specifically includes:

[0069] First: The autocorrelation calculation of the Bluetooth signal preamble.

[0070] The Bluetooth signals include BR, EDR, and BLE. Since the preambles of the BR and EDR frame formats are the same and both are 4 bits in length, the preambles of the BR and EDR frame formats are denoted as P BR / EDR ; the preamble length of the BLE-1M frame format is 8 bits, denoted as P BLE1M ; the preamble length of the BLE-2M frame format is 16 bits, denoted as P BLE2M ; the preamble length of the BLE-Coded (125 kb / s or 500 kb / s) frame format is 80 bits, denoted as P BLE80 .

[0071] Based on the feature of the different preamble lengths of the Bluetooth signals, it is determined whether the signal received by the Bluetooth tester is a BLE signal.

[0072] At the receiving end of the Bluetooth tester, the received signal is denoted as R(t), where t is the time variable; then, a phase difference operation is performed on the received signal R(t) to obtain the phase difference sequence of the received signal:

[0073] L(n), n = 0, 1, … N-1

[0074] That is:

[0075] L(n) = Φ(R(t)), n = 0, 1, … N-1

[0076] where Φ represents the phase difference operation function and N represents the sequence length;

[0077] The phase difference sequence L(n) of the received signal is respectively correlated with the preambles P BLE80 , P BLE2M and P BLE1M for correlation operations, that is:

[0078] K = Α((P BLE80 , P BLE2M , P BLE1M ), L(n))

[0079] where Α is the correlation operation function and K is the correlation operation value.

[0080] The autocorrelation operation of the preamble, as shown in Figure 3 , the preambles of 80 bits, 16 bits, and 8 bits have different autocorrelation characteristics. Therefore, the preamble can be used to determine BLE-1M, BLE-1M, and BLE-Coded (125 kb / s or 500 kb / s). The present invention uses the magnitude of the K value to determine whether it is BLE-1M, BLE-1M, and BLE-Coded (125 kb / s or 500 kb / s).

[0081] When the Bluetooth signal is BLE-Coded, BLE-Coded includes BLE125K and BLE500K. The distinction between BLE125K and BLE500K is made by using the last bit of the accessAddress after FEC decoding to carry the information distinguishing BLE125K and BLE500K. When this bit is 1, it represents BLE500K, and when it is 0, it represents BLE125K.

[0082] Second: High-order cumulant parameter calculation.

[0083] The modulation methods of Bluetooth signals mainly include two methods: GFSK and DPSK. Among them, BR and BLE use GFSK modulation; the header part of EDR uses GFSK, and the payload part of EDR uses DPSK modulation; the high-order cumulants of the modulated Bluetooth signals are used to distinguish BR, EDR, and BLE.

[0084] The description of high-order cumulants is as follows:

[0085] For a zero-mean complex stationary random process R(t), its p-order mixed moment can be expressed as:

[0086] M pq =E[R(t) p-q R * (t) q

[0087] Among them, * represents the conjugate of the function, and the high-order cumulant is defined as:

[0088]

[0089] The high-order cumulant values of different Bluetooth signal frame rate types are as Figure 1 shown. From Figure 1 it can be seen that the high-order cumulants of different Bluetooth signal frame rate types are different, and the Bluetooth signal frame rate type can be identified according to the differences in high-order cumulants.

[0090] In this embodiment, 3 characteristic parameters are selected from the second-order, fourth-order, and sixth-order cumulants of the high-order cumulant for identifying the Bluetooth signal frame rate type, namely:

[0091]

[0092] Among them, F1 is used to judge BR signals, F2 is used to judge EDR signals, and F3 is used to judge BLE signals.

[0093] Third: Judging the frame rate type based on the peak-to-average power ratio of the Bluetooth signal.

[0094] ​The decision of the EDR signal requires the use of the synchronization sequence. According to the Bluetooth protocol, the synchronization sequence of EDR2M is: syn2M = [0 0 0 1 1 1 0 1 1 1 0 1 1 1 1 1 0 1 0 1 0 1]; the synchronization sequence of EDR3M is: syn3M = [0 0 00 1 0 1 1 1 0 1 0 1 1 1 0 1 0 1 1 1 1 1 1 0 1 0 0 1 0 0 1 0];

[0095] Perform DPSK modulation on the synchronization sequences of EDR2M and EDR3M respectively. At the receiving end of the Bluetooth tester, the received signal R(t) and the synchronization sequence are subjected to a correlation operation to obtain:

[0096] K EDR K(t) = Α((syn2M, syn3M), R(t))

[0097] The correlation value K EDR The peak value of K(t) is denoted as K H ; the correlation value K EDR The average value of K(t) is denoted as K M ; the ratio of the peak value to the average value of the correlation value is: K peak = K H / K M .

[0098] Judge whether it is an EDR signal through K peak = K H / K M : When K peak is greater than a certain threshold, it is an EDR signal, otherwise it is not an EDR signal; among them, the value of the threshold needs to be determined according to the communication environment of the Bluetooth signal. In this embodiment, the peak-to-average ratios in the case of different frame rates of the Bluetooth signal are as Figure 4 shown, which are the peak-to-average ratios of BR, EDR2M, EDR3M, and BLE frame signals respectively. From Figure 4 it can be seen that EDR2M and EDR3M have obvious peak effects, so the peak-to-average ratio can be used to judge the frame rates of EDR2M and EDR3M.

[0099] Fourth: Determine the frame rate type based on the packet type of the Bluetooth signal.

[0100] Since the decision of EDR-2M and EDR-3M requires the use of the packet type detected during the synchronization header parsing, and then further refinement and differentiation are carried out.

[0101] According to the Bluetooth protocol, the preamble of the frame header has 4 bits carrying the packet type information. After accurately locating the frame header position of the Bluetooth signal, find the preamble carrying the packet type information, and then determine the packet type according to the preamble.

[0102] The 4-bit packet types include NULL, POLL, FHS, DV, HV1, HV2, HV3, EV3, EV4, EV5, DM1, DH1, DM3, DH3, DM5, DH5, AUX1, 2-EV3, 2-EV5, 2-DH1, 2-DH3, 2-DH5, 3-EV3, 3-EV5, 3-DH1, 3-DH3, and 3-DH5;

[0103] When the packet type detection result is 2-EV3, 2-EV5, 2-DH1, 2-DH3, or 2-DH5, it is determined as EDR2M;

[0104] When the packet type detection result is 3-EV3, 3-EV5, 3-DH1, 3-DH3, or 3-DH5, it is determined as EDR3M;

[0105] Based on the packet type detection result, the determination of the frame rate type is completed.

[0106] Working principle: At the receiving end of the Bluetooth tester, first perform correlation operations on the received signal with the 80-bit preamble, 16-bit preamble, and 8-bit preamble respectively. Then, determine the correlation operation values. When the peak values corresponding to the 80-bit preamble, 16-bit preamble, and 8-bit preamble are satisfied, it is determined as BLE-Coded (125kb / s or 500kb / s), BLE2M, and BLE1M respectively. Otherwise, the signal is considered to be in the BR / EDR mode. Since the high-order cumulant calculation values of the communication signals in different debugging methods will show significant differences, and the modulation methods of BR, EDR, and BLE have different combinations of GFSK and DPSK, the high-order cumulant of the Bluetooth signal is used to distinguish BR, EDR, and BLE. Further, the determination of the EDR mode Bluetooth signal requires the use of the peak ratio. Because the EDR mode has a clear 33-bit and 22-bit synchronization sequence, which is different from the synchronization sequences of BR and BLE. The distinction between EDR2M, EDR3M, BLE125K, and BLE500K requires the use of the packet type detection result.

[0107] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0108] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for identifying the signal mode type of a Bluetooth comprehensive tester, characterized in that: The recognition method includes the following steps: Step 1, autocorrelation calculation of the Bluetooth signal preamble When the Bluetooth signal is in BR, EDR-2M or EDR-3M mode, the preamble is 4 bits; When the Bluetooth signal is BLE-Coded, the preamble is 80 bits; When the Bluetooth signal is BLE-2M, the preamble is 16 bits; When the Bluetooth signal is BLE-1M, the preamble is 8 bits; At the receiving end of the Bluetooth tester, first perform correlation operations on the received signal with the 80-bit preamble, 16-bit preamble, and 8-bit preamble respectively, and judge the correlation operation values. When the peaks corresponding to the 80-bit preamble, 16-bit preamble, and 8-bit preamble are satisfied, it is judged as BLE-Coded, BLE-2M, and BLE-1M respectively, otherwise the signal is considered to be in BR / EDR mode; Step 2, calculation of the high-order cumulant parameters of the Bluetooth signal The modulation methods of the Bluetooth signal include GFSK and DPSK. Among them, BR and BLE use GFSK modulation, the header part of EDR uses GFSK modulation, and the payload part of EDR uses DPSK modulation; Distinguish BR, EDR, and BLE by judging the high-order cumulants of the modulated Bluetooth signal; Step 3, judge the frame rate type based on the peak-to-average ratio of the Bluetooth signal: According to the Bluetooth protocol, perform DPSK modulation on the synchronization sequence of the EDR signal; At the receiving end of the Bluetooth comprehensive tester, the received signal R(t) is correlated with the synchronization sequence to obtain the correlation value K EDR (t); The ratio of the peak value to the average value of the correlation value is: K peak = K H / K M Pass through K peak = K H / K M Judge whether it is an EDR signal: When K peak is greater than the threshold value, it is an EDR signal, otherwise it is not an EDR signal; among them, the value of the threshold is determined according to the communication environment of the Bluetooth signal; Step 4, judge the frame rate type based on the packet type of the Bluetooth signal: According to the Bluetooth protocol, the preamble of the header carries packet type information. After locating the header position of the Bluetooth signal, find the preamble carrying the packet type information, and then determine the packet type according to the preamble; The specific content of Step 4 includes: When the packet type detection result is 2-EV3, 2-EV5, 2-DH1, 2-DH3, and 2-DH5, it is judged as EDR-2M; When the packet type detection result is 3-EV3, 3-EV5, 3-DH1, 3-DH3, and 3-DH5, it is judged as EDR-3M; Based on the packet type detection result, complete the judgment of the frame rate type.

2. The recognition method according to claim 1, characterized in that The specific content of Step 1 includes: The preambles of the BR and EDR frame formats are denoted as P BR / EDR ; The preamble of the BLE-1M frame format is denoted as P BLE1M ; The preamble of the BLE-2M frame format is denoted as P BLE2M ; The preamble of the BLE-Coded frame format is denoted as P BLE80 ; At the receiving end of the Bluetooth tester, the received signal is expressed as R(t), where t is the time variable; then perform a phase difference operation on the received signal R(t) to obtain the phase difference sequence of the received signal R(t): L(n), n = 0, 1, … N-1 That is: L(n) = Φ(R(t)), n = 0, 1, … N-1 Among them, Φ represents the phase difference operation function, and N represents the sequence length; The phase difference sequence L(n) of the received signal is respectively correlated with the preambles P BLE80 , P BLE2M and P BLE1M by performing correlation operations, that is: K = Α((P BLE80 , P BLE2M , P BLE1M ), L(n)) Among them, Α is the correlation operation function, and K is the correlation operation value.

3. The recognition method according to claim 2, characterized in that, The specific content of Step 2 includes: For the zero-mean complex stationary random process R(t), its p-order mixed moment is expressed as: M pq = E[R(t) p-q R * (t) q ​ Among them, * represents the conjugate of the function, and the high-order cumulant is defined as: The high-order cumulants of different Bluetooth signal frame rate types are different, and the recognition of the Bluetooth signal frame rate type is completed according to the differences in the high-order cumulants.

4. The recognition method according to claim 3, wherein: Three characteristic parameters are selected from the second-order, fourth-order, and sixth-order cumulants of the high-order cumulants for Bluetooth signal frame rate type identification, namely: Among them, F1 is used to judge BR signals, F2 is used to judge EDR signals, and F3 is used to judge BLE signals.

Images