CN113497775B - High-sensitivity receiving method in coded mode of Bluetooth receiver - Google Patents

High-sensitivity receiving method in coded mode of Bluetooth receiver Download PDF

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CN113497775B
CN113497775B CN202111042215.6A CN202111042215A CN113497775B CN 113497775 B CN113497775 B CN 113497775B CN 202111042215 A CN202111042215 A CN 202111042215A CN 113497775 B CN113497775 B CN 113497775B
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frequency offset
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estimation value
frequency
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CN113497775A (en
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刘德良
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Nanjing Qinheng Microelectronics Co ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2657—Carrier synchronisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/80—Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

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Abstract

The invention discloses a high-sensitivity receiving method under a coded mode of a Bluetooth receiver, which comprises the steps of detecting a frame header by utilizing the characteristic of signal repetition in a frame header format in a synchronous capturing stage, obtaining a total frequency deviation estimated value through two times of frequency deviation estimation, and determining the position of a subsequent access code; in the synchronous tracking stage, a frequency offset tracking loop is provided for tracking residual frequency offset based on the pseudo-random characteristic of signal transmission by utilizing the characteristic that a Bluetooth signal adopts GMSK constant envelope modulation, and finally a receiver can correctly compensate the frequency offset, so that the receiver can improve the demodulation performance of the GMSK signal by adopting quasi-coherent demodulation. The invention can realize the synchronous capture of signals under the scenes of large frequency deviation and low signal-to-noise ratio, can obtain correct frequency deviation estimation value and sampling position estimation value even if the signal-to-noise ratio is as low as 0dB, and can continuously track the signal frequency after capturing the signals, thereby laying a foundation for the demodulation of the signals.

Description

High-sensitivity receiving method in coded mode of Bluetooth receiver
Technical Field
The invention belongs to the technical field of wireless communication, and particularly relates to a high-sensitivity receiving method in a coded mode of a Bluetooth receiver.
Background
Compared with the unicoded mode, the bluetooth 5.0 coded mode is an extended transmission distance, and formats of a Preamble (hereinafter, referred to as a frame header) part and a PDU part are modified. The Preamble part consists of 10 repeated symbol sequences of '00111100', and the PDU part is added with error correction coding with code rate of 1/8 or 1/2. For this reason, a receiving method different from the unicoded mode is required to improve the sensitivity of the receiver and extend the communication distance. How to solve the problem that the sensitivity of a receiver is influenced by the strength reduction of a distance extension receiving signal and the reduction of a signal-to-noise ratio under the condition of the same transmitting power is a technical difficulty faced by a Bluetooth 5.0 coded mode.
Disclosure of Invention
The purpose of the invention is as follows: in order to solve the problem that the sensitivity of a Bluetooth receiver in a 5.0 coded mode is poor in the prior art, the invention provides a high-sensitivity receiving method in the coded mode of the Bluetooth receiver.
The technical scheme is as follows: a high-sensitivity receiving method under a coded mode of a Bluetooth receiver comprises the following steps:
step one, sampling a received signal, detecting a frame header in a differential operation mode, and obtaining a differential summation operation result of a sampling point
Figure 636593DEST_PATH_IMAGE001
；
Setting the total frequency deviation estimated value as
Figure 147209DEST_PATH_IMAGE002
Establishing
Figure 723684DEST_PATH_IMAGE002
The composition of (A):
Figure 853314DEST_PATH_IMAGE003
（1）
wherein the content of the first and second substances,
Figure 261161DEST_PATH_IMAGE004
t is the symbol transmission period, j may take the values-1, 0, + 1;
step three, respectively assuming that j takes the values of-1, 0 and +1, and performing frequency offset compensation on the received signal to obtain three frequency offset compensation results; construction of local training sequences
Figure 880361DEST_PATH_IMAGE005
，
Figure 616236DEST_PATH_IMAGE006
And Ts is the sampling period,
Figure 688839DEST_PATH_IMAGE007
represents a transmitted signal; performing correlation operation on the local training sequence and the three frequency offset compensation results respectively, taking a j value of the frequency offset compensation result corresponding to the maximum correlation value, and bringing the j value into the formula (1) to obtain a total frequency offset estimation value;
step four, determining the initial position of the access code;
and fifthly, performing frequency compensation on the received signal by using the total frequency offset estimation value obtained in the third step, performing error detection on the frequency-compensated signal to obtain a residual frequency offset estimation value, accumulating the residual frequency offset estimation value and the total frequency offset estimation value after filtering by a loop filter, updating the total frequency offset estimation value, performing frequency compensation by using the updated total frequency offset estimation value, and demodulating the frequency-compensated signal by using a quasi-coherent demodulation method.
Further, the method for detecting the frame header in the first step comprises the following steps:
let the transmitted signal be represented as
Figure 826560DEST_PATH_IMAGE008
The received signal is represented as
Figure 616661DEST_PATH_IMAGE009
Wherein
Figure 230045DEST_PATH_IMAGE010
Is an additive white gaussian noise, and is,
Figure 140626DEST_PATH_IMAGE011
for frequency offset of both sides of the transceiver, setting the transmission period of the code element as T, the sampling number of each code element transmission period as L, and the sampling interval as Ts = T/L, calculating:
Figure 991907DEST_PATH_IMAGE012
(2)
Figure 484068DEST_PATH_IMAGE013
(3)
Figure 522431DEST_PATH_IMAGE014
representing the result of a difference operation between two samples separated by a time of 8T,
Figure 859872DEST_PATH_IMAGE015
as an intermediate parameter, the parameter is,
Figure 237764DEST_PATH_IMAGE016
representing the number of samples participating in the difference operation, and defining the detection index as
Figure 369668DEST_PATH_IMAGE017
，
Figure 957644DEST_PATH_IMAGE018
(4)
When the detection index exceeds the threshold
Figure 505300DEST_PATH_IMAGE019
When the received signal contains frame head signal, recording the first time exceeding threshold
Figure 802945DEST_PATH_IMAGE020
。
Further, in step three, the method for calculating the frequency offset compensation result according to the assumption is as follows:
respectively assuming that j takes the values of +1, -1 and 0, constructing a sequence with the length of K
Figure 433646DEST_PATH_IMAGE021
，
Figure 181022DEST_PATH_IMAGE022
(5)
Wherein the content of the first and second substances,
Figure 797948DEST_PATH_IMAGE023
，
respectively using the sequences
Figure 947170DEST_PATH_IMAGE021
And the following operation is carried out with the received signal:
Figure 483194DEST_PATH_IMAGE024
(6)
Figure 655549DEST_PATH_IMAGE025
respectively assuming a frequency offset of
Figure 872904DEST_PATH_IMAGE026
、
Figure 204528DEST_PATH_IMAGE027
And
Figure 114715DEST_PATH_IMAGE028
and then performing frequency offset compensation.
Further, in step three, the phases of the correlation operations are respectively set to be
Figure 508787DEST_PATH_IMAGE029
、
Figure 595079DEST_PATH_IMAGE030
And 0, the values of the corresponding elements are selected from the set
Figure 453314DEST_PATH_IMAGE031
While the elements with the phase at the other values are forced to be zero,
Figure 472086DEST_PATH_IMAGE032
is taken from
Figure 478088DEST_PATH_IMAGE033
Then the following correlation operations are carried out:
Figure 302824DEST_PATH_IMAGE034
(7)
in that
Figure 218828DEST_PATH_IMAGE035
Searching for the maximum correlation value in equation (7) within the range,
Figure 205238DEST_PATH_IMAGE036
the frequency offset compensation value corresponding to the maximum correlation value is the correct frequency offset estimation value.
And further, determining the position of the access code by adopting an anti-interference high-precision signal synchronization method based on the access code according to the approximate position of the frame header to finish signal synchronization acquisition.
Further, in step five, the method for obtaining the residual frequency offset estimation value through error detection comprises:
let the phase of the modulated Bluetooth signal be represented as
Figure 964116DEST_PATH_IMAGE037
，The phase of the received signal is represented as
Figure 326964DEST_PATH_IMAGE038
Residual frequency deviation of
Figure 97474DEST_PATH_IMAGE039
The residual frequency offset estimation value is
Figure 317103DEST_PATH_IMAGE040
，
Figure 173063DEST_PATH_IMAGE041
（8）
Wherein the content of the first and second substances,
Figure 330813DEST_PATH_IMAGE042
is the first of transmissionnA code element, which takes the value of +1 or-1;his a modulation index, and the value of the modulation index is 0.5;
Figure 814884DEST_PATH_IMAGE043
the response of a rectangular pulse with the length of a code element period through a Gaussian filter is satisfied
Figure 346360DEST_PATH_IMAGE044
；
NT represents the integration time length, the value of NT is calculated from equation (9),
Figure 548671DEST_PATH_IMAGE045
（9）
neglecting the effect of noise, there are:
Figure 784480DEST_PATH_IMAGE046
（10）
estimated from equations (9) and (10):
Figure 264003DEST_PATH_IMAGE047
（11）
calculating a residual frequency offset estimation value
Figure 28697DEST_PATH_IMAGE048
I.e. the result of the error detection.
Further, if the samples of the received signal are oversampled, then the summation is used in the calculation of equation (11).
Further, the loop filter employs a first or second order loop filter.
Further, in step five, the signal after frequency compensation is demodulated by adopting a 1-bit differential demodulation method based on decision or a quasi-coherent demodulation method based on source decomposition.
A bluetooth receiver comprising a processor, a memory and a software program stored in the memory and executable by the processor, the software program when executed by the processor enabling a high sensitivity receiving method in coded mode of the bluetooth receiver as described above.
Has the advantages that: compared with the prior art, the invention can realize the synchronous capture of signals under the scenes of large frequency deviation and low signal to noise ratio, can obtain correct frequency deviation estimated values and sampling position estimated values even if the signal to noise ratio is as low as 0dB, and greatly reduces the operation complexity under the condition of correctly estimating the frequency deviation value. And after capturing the signal, a frequency offset tracking loop is provided for tracking residual frequency offset based on the pseudorandom characteristic of signal transmission, the signal frequency can be tracked at any time, so that the influence of frequency offset on the demodulation of the Bluetooth GMSK signal is reduced as much as possible, a foundation is laid for the demodulation of the signal, and a receiver can improve the demodulation performance of the GMSK signal by adopting quasi-coherent demodulation.
Drawings
FIG. 1 is a graph of timing synchronization performance affected by signal-to-noise ratio;
FIG. 2 shows a timing offset with a signal-to-noise ratio of 0 dB;
FIG. 3 is a graph of the performance of frequency offset estimation affected by signal-to-noise ratio;
FIG. 4 is a schematic flow chart of the method of the present invention.
Detailed Description
The invention is further explained below with reference to the figures and the specific embodiments.
A Bluetooth receiver includes a processor, a memory, and a software program stored in the memory and executable by the processor, and when the software program is executed by the processor, a high-sensitivity receiving method in a coded mode of the Bluetooth receiver described below can be realized.
The high-sensitivity receiving method in the coded mode of the bluetooth receiver, as shown in fig. 4, includes the following steps:
step one, sampling the received signal, because the frame header part is composed of 10 repeated symbol sequences of '00111100', the regular repetition of the frame header part can be utilized to detect the signal, so that the receiver can detect the information of the frame header part in the received signal. In the process of detecting the frame head, the differential summation operation result of the sampling point can be obtained
Figure 718304DEST_PATH_IMAGE049
；
The method for detecting the frame header by the differential operation mode comprises the following steps:
let the transmitted signal be represented as
Figure 164329DEST_PATH_IMAGE050
Symbol period of
Figure 826254DEST_PATH_IMAGE051
Then, then
Figure 558587DEST_PATH_IMAGE052
. Assuming that it is only affected by white noise, the received signal is represented as
Figure 876436DEST_PATH_IMAGE053
Wherein
Figure 925819DEST_PATH_IMAGE054
Is an additive white gaussian noise, and is,
Figure 770147DEST_PATH_IMAGE055
are frequency offsets of both the transmitting and receiving sides. Assuming that a symbol transmission period is T, the number of samples per symbol transmission period is L, and a sampling interval is Ts = T/L, the following is calculated:
Figure 876643DEST_PATH_IMAGE056
(1)
Figure 416209DEST_PATH_IMAGE057
(2)
wherein
Figure 531933DEST_PATH_IMAGE058
Presentation pair
Figure 965188DEST_PATH_IMAGE059
Taking the result of the conjugation as a result,
Figure 180269DEST_PATH_IMAGE060
representing the result of a difference operation between two samples separated by a time of 8T,
Figure 269447DEST_PATH_IMAGE061
representing the number of samples participating in the difference operation,
Figure 985600DEST_PATH_IMAGE062
for the intermediate parameter, defining the detection index as
Figure 476624DEST_PATH_IMAGE063
，
Figure 597026DEST_PATH_IMAGE064
(3)
When detecting the index
Figure 504327DEST_PATH_IMAGE065
Exceeds a predetermined threshold
Figure 368378DEST_PATH_IMAGE066
When the frame header signal is included in the received signal, the received signal is considered to contain the frame header signal. Recording the moment when the threshold is exceeded for the first time
Figure 713909DEST_PATH_IMAGE067
。
If the influence of noise is ignored due to the signal repeatability of the frame header part, it is assumed that
Figure 395426DEST_PATH_IMAGE068
The time is the time corresponding to the first sample value of the frame header part, namely the signal detection achieves the complete accuracy of the position, and the formula (1) can be simplified into
Figure 396880DEST_PATH_IMAGE069
(4)
The step detects the frame head and obtains the result of sampling point difference summation
Figure 392518DEST_PATH_IMAGE070
And the frequency offset is used for the next frequency offset estimation.
Step two, considering phase ambiguity, if frequency deviation
Figure 389292DEST_PATH_IMAGE071
Then its estimated value
Figure 382656DEST_PATH_IMAGE072
T is the symbol transmission period, otherwise
Figure 730461DEST_PATH_IMAGE073
. Order to
Figure 264210DEST_PATH_IMAGE074
，
Figure 256437DEST_PATH_IMAGE075
Then:
Figure 545336DEST_PATH_IMAGE076
（5）
wherein the content of the first and second substances,
Figure 990224DEST_PATH_IMAGE077
，
Figure 330594DEST_PATH_IMAGE078
given the maximum frequency offset specification in the protocol, j may take the value-1, 0, or + 1. The value of j needs to be estimated next.
Step three, respectively assuming j to take the values of +1, 0 and-1, and constructing a sequence with the length of K
Figure 833120DEST_PATH_IMAGE079
，
Figure 637128DEST_PATH_IMAGE080
(6)
Wherein the content of the first and second substances,
Figure 162787DEST_PATH_IMAGE081
. Obviously, the above sequences assume frequency offsets of
Figure 100656DEST_PATH_IMAGE082
、
Figure 67475DEST_PATH_IMAGE083
And
Figure 370280DEST_PATH_IMAGE084
。
then using the above sequences separately
Figure 445552DEST_PATH_IMAGE021
And the following operation is carried out with the received signal:
Figure 796899DEST_PATH_IMAGE085
(7)
Figure 946121DEST_PATH_IMAGE086
respectively assuming a frequency offset of
Figure 482144DEST_PATH_IMAGE087
、
Figure 654500DEST_PATH_IMAGE088
And
Figure 495741DEST_PATH_IMAGE089
and then performing frequency offset compensation.
After three frequency offset compensation results are obtained, a local training sequence is constructed
Figure 765048DEST_PATH_IMAGE090
，
Figure 81760DEST_PATH_IMAGE091
And Ts is the sampling period,
Figure 866045DEST_PATH_IMAGE092
represents a transmitted signal; performing correlation operation on the local training sequence and the three frequency offset compensation results respectively, taking a j value of the frequency offset compensation result corresponding to the maximum correlation value, and bringing the j value into the formula (5) to obtain a total frequency offset estimation value;
because the sending signal of the bluetooth adopts a GMSK constant envelope modulation mode, the sequence constructed by the formula (7) is a complex value sequence, and the correlation operation can bring greater complexity. For this purpose, only the phases in the sequence may be takenBit is close to
Figure DEST_PATH_IMAGE093
、
Figure 355932DEST_PATH_IMAGE094
And 0 elements, respectively, having phases of
Figure 542063DEST_PATH_IMAGE093
、
Figure 623151DEST_PATH_IMAGE094
And 0, the values of the corresponding elements are selected from the set
Figure 504520DEST_PATH_IMAGE095
While elements with other values of phase are forced to zero. At this point in time,
Figure 125994DEST_PATH_IMAGE096
is taken from
Figure 776418DEST_PATH_IMAGE097
Selecting. The following correlation is then performed:
Figure 28408DEST_PATH_IMAGE098
(8)
although the position of the frame header is roughly found by means of detection in the step one
Figure 790215DEST_PATH_IMAGE099
However, since the position is not exact, it is necessary to perform correlation operation in a certain range, for example, to limit a range
Figure 825167DEST_PATH_IMAGE100
Searching for the maximum correlation value in equation (8) within the range,
Figure 657994DEST_PATH_IMAGE101
are respectively setThe frequency offset compensation value corresponding to the maximum correlation value is the correct frequency offset estimation value. For example, in the present embodiment,
Figure 877623DEST_PATH_IMAGE102
if the maximum correlation value occurs, the total frequency offset estimation value is
Figure 999162DEST_PATH_IMAGE103
. The position at which the correlation peak occurs is recorded simultaneously as
Figure 493598DEST_PATH_IMAGE104
。
Step four, obtaining correct estimated value through step three
Figure 384193DEST_PATH_IMAGE105
Next, the correct signal sampling location needs to be obtained, and the approximate location has been obtained in the context of the determination of the total frequency offset estimate
Figure 977986DEST_PATH_IMAGE106
Further searching for more accurate locations is needed. Since the bluetooth communication protocol sends the access code after the frame header, the access code is known to both the transceiver and the access code has better randomness. Therefore, based on the access code-based anti-interference high-precision signal synchronization method in the bluetooth receiver of another patent with patent number 2020111383050 of the present applicant, the access code can be used to realize the search of the start and stop positions of the accurate access code, and realize the synchronous acquisition of the signal, thereby making full preparation for the following signal demodulation.
Fig. 1 shows the performance of timing synchronization under various signal-to-noise ratio conditions when the method is used for signal synchronization acquisition. Even with a signal-to-noise ratio as low as 0dB, the probability of false synchronization (missed synchronization and false synchronization) is only 3%. FIG. 2 shows the oversampling factorLThe distribution of timing deviation is shown in the case of 8. At a signal-to-noise ratio of 0dB, the vast majority of timing skew is controlled within two samples. FIG. 3 shows frequency offset estimation under various SNR conditionsPerformance, the ordinate axis of the coordinate axis shows the root mean square error normalized to the symbol rate. It can be seen that the root mean square error of the frequency offset estimation is basically controlled to be 2kWithin Hz.
Step five, from the above steps, the synchronous acquisition of the signal is realized, but from the view of the Bluetooth protocol, the maximum frequency drift rate of the Bluetooth signal in the transmission process can reach
Figure 180297DEST_PATH_IMAGE107
. Therefore, it is necessary to continuously track the frequency offset to reduce the influence of the frequency offset on the demodulation of the bluetooth GMSK signal as much as possible. To this end, a tracking method of a frequency offset tracking loop is provided.
And C, performing frequency compensation on the received signal by using the total frequency offset estimation value obtained in the step three, wherein certain residual frequency offset exists in the received signal after frequency offset compensation, and performing error detection on the signal after frequency compensation to obtain a residual frequency offset estimation value
Figure 88210DEST_PATH_IMAGE108
Residual frequency offset estimation
Figure 692367DEST_PATH_IMAGE109
Obtaining more accurate residual frequency offset estimation value through loop filter
Figure 129164DEST_PATH_IMAGE110
。
Specific acquisition
Figure 24964DEST_PATH_IMAGE109
The method comprises the following steps: let the phase of the modulated Bluetooth signal be represented as
Figure 533305DEST_PATH_IMAGE111
The phase of the received signal is
Figure 585444DEST_PATH_IMAGE112
Residual frequency deviation of
Figure 521039DEST_PATH_IMAGE113
The residual frequency offset estimation value is
Figure 838888DEST_PATH_IMAGE114
Figure 885341DEST_PATH_IMAGE115
（9）
Wherein the content of the first and second substances,
Figure 729669DEST_PATH_IMAGE116
is the first of transmissionnA code element, which takes the value of +1 or-1;his a modulation index, and the value of the modulation index is 0.5;
Figure 836166DEST_PATH_IMAGE117
the response of a rectangular pulse with the length of a code element period through a Gaussian filter is satisfied
Figure 641311DEST_PATH_IMAGE118
；
Due to the fact that
Figure 494385DEST_PATH_IMAGE116
Is a random + 1-1 sequence, therefore, based on the pseudo-random characteristic of Bluetooth signal transmission, the pair can be considered to be transmitted within a period of time
Figure 193219DEST_PATH_IMAGE119
Result of integration
Figure 142721DEST_PATH_IMAGE120
Let NT denote the integration time length, the value of NT is calculated from equation (10),
Figure 231899DEST_PATH_IMAGE121
（10）
the receiving end ignores the influence of noise due to the existence of frequency offset, and then:
Figure 948051DEST_PATH_IMAGE122
（11）
thus corresponding integration result
Figure 439076DEST_PATH_IMAGE123
Wherein
Figure 559478DEST_PATH_IMAGE124
Indicating the residual frequency offset, i.e. the tracking error in the tracking phase.
Further calculating residual frequency deviation estimated value
Figure 463849DEST_PATH_IMAGE125
，
Figure 655796DEST_PATH_IMAGE126
（12）。
If the samples of the received signal are oversampled, then the calculation of equation (12) may be replaced by a summation.
Residual frequency deviation estimated value detected by error
Figure 939010DEST_PATH_IMAGE125
Sending the signal into a loop filter to eliminate the influence of noise as much as possible and obtain a more accurate estimated value
Figure 620527DEST_PATH_IMAGE127
. The loop filter may employ a first or second order loop filter.
Residual frequency offset estimation value
Figure 356402DEST_PATH_IMAGE110
Frequency offset estimation from previous time
Figure 77672DEST_PATH_IMAGE128
Accumulating to obtain the frequency deviation estimated value of the current time
Figure 340026DEST_PATH_IMAGE129
Using updated
Figure 333389DEST_PATH_IMAGE129
The frequency compensation is carried out, demodulation can be carried out after the frequency offset compensation, and a 1-bit differential demodulation method based on judgment or a quasi-coherent demodulation method based on source decomposition and the like can be adopted for the demodulation of the GMSK signal.

Claims (9)

1. A high-sensitivity receiving method under a coded mode of a Bluetooth receiver is characterized by comprising the following steps:
step one, sampling a received signal, detecting a frame header in a differential operation mode, and obtaining a differential summation operation result of a sampling point
Figure DEST_PATH_IMAGE001
；
Setting the total frequency deviation estimated value as
Figure DEST_PATH_IMAGE002
Establishing
Figure 195522DEST_PATH_IMAGE002
The composition of (A):
Figure DEST_PATH_IMAGE003
（1）
wherein the content of the first and second substances,
Figure DEST_PATH_IMAGE004
t is the symbol transmission period, j may take the values-1, 0, + 1;
step three, respectively assuming that j takes the values of-1, 0 and +1, and performing frequency offset compensation on the received signal to obtain three frequency offset compensation results; construction of local training sequences
Figure DEST_PATH_IMAGE005
，
Figure DEST_PATH_IMAGE006
And Ts is the sampling period,
Figure DEST_PATH_IMAGE007
represents a transmitted signal; performing correlation operation on the local training sequence and the three frequency offset compensation results respectively, taking a j value of the frequency offset compensation result corresponding to the maximum correlation value, and bringing the j value into the formula (1) to obtain a total frequency offset estimation value;
step four, determining the initial position of the access code;
fifthly, frequency compensation is carried out on the received signal by using the total frequency offset estimation value obtained in the third step, error detection is carried out on the signal after frequency compensation to obtain a residual frequency offset estimation value, the residual frequency offset estimation value is accumulated with the total frequency offset estimation value after being filtered by a loop filter to update the total frequency offset estimation value, frequency compensation is carried out by using the updated total frequency offset estimation value, the signal after frequency compensation is demodulated by adopting a quasi-coherent demodulation method,
the method for obtaining the residual frequency offset estimation value by carrying out error detection on the frequency compensated signal comprises the following steps:
let the phase of the modulated Bluetooth signal be represented as
Figure DEST_PATH_IMAGE008
，The phase of the received signal is represented as
Figure DEST_PATH_IMAGE009
Residual frequency deviation of
Figure DEST_PATH_IMAGE010
The residual frequency offset estimation value is
Figure DEST_PATH_IMAGE011
，
Figure DEST_PATH_IMAGE012
（8）
Wherein the content of the first and second substances,
Figure DEST_PATH_IMAGE013
is the first of transmissionnA code element, which takes the value of +1 or-1;his a modulation index, and the value of the modulation index is 0.5;
Figure DEST_PATH_IMAGE014
the response of a rectangular pulse with the length of a code element period through a Gaussian filter is satisfied
Figure DEST_PATH_IMAGE015
；
NT represents the integration time length, the value of NT is calculated from equation (9),
Figure DEST_PATH_IMAGE016
（9）
neglecting the effect of noise, there are:
Figure DEST_PATH_IMAGE017
（10）
estimated from equations (9) and (10):
Figure DEST_PATH_IMAGE018
（11）
calculating a residual frequency offset estimation value
Figure DEST_PATH_IMAGE019
I.e. the result of the error detection.
2. The method for receiving with high sensitivity in coded mode of bluetooth receiver according to claim 1, wherein the method for detecting the frame header in the first step comprises:
order transmissionThe signal is represented as
Figure DEST_PATH_IMAGE020
The received signal is represented as
Figure DEST_PATH_IMAGE021
Wherein
Figure DEST_PATH_IMAGE022
Is an additive white gaussian noise, and is,
Figure DEST_PATH_IMAGE023
for frequency offset of both sides of the transceiver, setting the transmission period of the code element as T, the sampling number of each code element transmission period as L, and the sampling interval as Ts = T/L, calculating:
Figure DEST_PATH_IMAGE024
(2)
Figure DEST_PATH_IMAGE025
(3)
Figure DEST_PATH_IMAGE026
representing the result of a difference operation between two samples separated by a time of 8T,
Figure DEST_PATH_IMAGE027
as an intermediate parameter, the parameter is,
Figure DEST_PATH_IMAGE028
representing the number of samples participating in the difference operation, and defining the detection index as
Figure DEST_PATH_IMAGE029
，
Figure DEST_PATH_IMAGE030
(4)
When the detection index exceeds the threshold
Figure DEST_PATH_IMAGE031
When the received signal contains frame head signal, recording the first time exceeding threshold
Figure DEST_PATH_IMAGE032
。
3. The method for receiving high sensitivity data in coded mode of bluetooth receiver according to claim 2, wherein in step three, the method for calculating the frequency offset compensation result according to the hypothesis is:
respectively assuming that j takes the values of +1, -1 and 0, constructing a sequence with the length of K
Figure DEST_PATH_IMAGE033
，
Figure DEST_PATH_IMAGE034
(5)
Wherein the content of the first and second substances,
Figure DEST_PATH_IMAGE035
，
respectively using the sequences
Figure 507072DEST_PATH_IMAGE033
And the following operation is carried out with the received signal:
Figure DEST_PATH_IMAGE036
(6)
Figure DEST_PATH_IMAGE037
respectively, a hypothetical frequency offsetIs composed of
Figure DEST_PATH_IMAGE038
、
Figure DEST_PATH_IMAGE039
And
Figure DEST_PATH_IMAGE040
and then performing frequency offset compensation.
4. The method as claimed in claim 3, wherein in step three, the correlation operations are performed by setting the phases to be
Figure DEST_PATH_IMAGE041
、
Figure DEST_PATH_IMAGE042
And 0, the values of the corresponding elements are selected from the set
Figure DEST_PATH_IMAGE043
While the elements with the phase at the other values are forced to be zero,
Figure DEST_PATH_IMAGE044
is taken from
Figure DEST_PATH_IMAGE045
Then the following correlation operations are carried out:
Figure DEST_PATH_IMAGE046
(7)
in that
Figure DEST_PATH_IMAGE047
Searching for the maximum correlation value in equation (7) within the range,
Figure DEST_PATH_IMAGE048
the frequency offset compensation value corresponding to the maximum correlation value is the correct frequency offset estimation value.
5. The method for receiving with high sensitivity in coded mode of bluetooth receiver according to any of claims 1 to 4, characterized in that, in the fourth step, according to the approximate position of the frame header, the position of the access code is determined by using the anti-interference high precision signal synchronization method based on the access code, so as to complete the signal synchronization acquisition.
6. The method of claim 1, wherein if the samples of the received signal are oversampled, then formula (11) is calculated by summing instead.
7. The method for receiving with high sensitivity in coded mode of a bluetooth receiver according to any of claims 1 to 4, wherein the loop filter is a first or second order loop filter.
8. The high-sensitivity receiving method in coded mode of bluetooth receiver according to any of claims 1 to 4, characterized in that in step five, the signal after frequency compensation is demodulated by using decision-based 1-bit differential demodulation or by using quasi-coherent demodulation based on source decomposition.
9. A bluetooth receiver comprising a processor, a memory and a software program stored in the memory and executable by the processor, the software program when executed by the processor being operable to implement a method of high sensitivity reception in coded mode of the bluetooth receiver as claimed in any one of claims 1 to 8.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102415069A (en) * 2009-04-23 2012-04-11 皇家飞利浦电子股份有限公司 Frequency offset and channel gain tracking for enhanced transmission efficiency
US8223893B1 (en) * 2002-02-13 2012-07-17 Marvell International Ltd. Compensation for residual frequency offset, phase noise and sampling phase offset in wireless networks
CN202551094U (en) * 2012-02-09 2012-11-21 泰凌微电子（上海）有限公司 Frequency offset estimating and eliminating system
CN111212006A (en) * 2019-12-25 2020-05-29 奉加微电子（上海）有限公司 Signal demodulation system and demodulation method
CN111988108A (en) * 2020-10-22 2020-11-24 南京沁恒微电子股份有限公司 Anti-interference high-precision signal synchronization method based on access code in Bluetooth receiver

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8223893B1 (en) * 2002-02-13 2012-07-17 Marvell International Ltd. Compensation for residual frequency offset, phase noise and sampling phase offset in wireless networks
CN102415069A (en) * 2009-04-23 2012-04-11 皇家飞利浦电子股份有限公司 Frequency offset and channel gain tracking for enhanced transmission efficiency
CN202551094U (en) * 2012-02-09 2012-11-21 泰凌微电子（上海）有限公司 Frequency offset estimating and eliminating system
CN111212006A (en) * 2019-12-25 2020-05-29 奉加微电子（上海）有限公司 Signal demodulation system and demodulation method
CN111988108A (en) * 2020-10-22 2020-11-24 南京沁恒微电子股份有限公司 Anti-interference high-precision signal synchronization method based on access code in Bluetooth receiver

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