CN113542181A - Frequency offset estimation method, device, equipment and computer readable storage medium - Google Patents
Frequency offset estimation method, device, equipment and computer readable storage medium Download PDFInfo
- Publication number
- CN113542181A CN113542181A CN202111077899.3A CN202111077899A CN113542181A CN 113542181 A CN113542181 A CN 113542181A CN 202111077899 A CN202111077899 A CN 202111077899A CN 113542181 A CN113542181 A CN 113542181A
- Authority
- CN
- China
- Prior art keywords
- sequence
- interference
- point
- frequency offset
- value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 53
- 238000005070 sampling Methods 0.000 claims abstract description 56
- 230000001360 synchronised effect Effects 0.000 claims abstract description 22
- 239000013598 vector Substances 0.000 claims description 120
- 238000001914 filtration Methods 0.000 claims description 16
- 238000004590 computer program Methods 0.000 claims description 10
- 230000001502 supplementing effect Effects 0.000 claims description 7
- 230000011664 signaling Effects 0.000 claims description 5
- 238000010586 diagram Methods 0.000 description 33
- 238000012545 processing Methods 0.000 description 10
- 230000006870 function Effects 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000004891 communication Methods 0.000 description 4
- 239000000284 extract Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000036039 immunity Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 101100368149 Mus musculus Sync gene Proteins 0.000 description 1
- 238000004422 calculation algorithm Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Images
Classifications
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Noise Elimination (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
The application discloses a frequency offset estimation method, a device, equipment and a computer readable storage medium, wherein the method is applied to a receiving end and comprises the following steps: generating a local sequence based on the over-sampling multiple and the synchronous sequence, wherein the local sequence has a first preset number of numerical values, and the first preset number is larger than the number of symbols of the synchronous sequence; acquiring preset synchronization points and over-sampling sequences, and extracting a second preset number of numerical values from the over-sampling sequences to form a first candidate sequence by taking the preset synchronization points as starting points, wherein the second preset number is equal to the first preset number; and obtaining a frequency offset sequence according to the difference value of the first candidate sequence and the local sequence, and taking the average value of the frequency offset sequence as the output of frequency offset estimation. According to the method and the device, sampling point numerical values of the local sequence are increased by combining the oversampling multiple, and the accuracy and precision of frequency offset estimation are improved.
Description
Technical Field
The present disclosure relates to the field of mobile communications, and in particular, to a frequency offset estimation method, apparatus, device, and computer-readable storage medium.
Background
In the field of conventional intercom communication technology, a DMR (digital Mobile Radio) communication system is generally used. In the drawings of the present disclosure, fig. 1 shows a logic diagram of a baseband transmitter and a baseband receiver in a communication system, specifically, in a data processing flow of the baseband transmitter, first, synchronization sequence data (bit structure) to be transmitted is subjected to "bit-to-symbol" conversion to obtain synchronization sequence data (symbol structure) to be transmitted, and specifically, fig. 2 shows a 4FSK modulation diagram based on the baseband transmitter, it can be seen that, since a modulation mode of a DMR is 4FSK (Frequency Shift keying), a synchronization sequence to be transmitted with a bit structure is mapped onto 1 Frequency domain symbol every two bits according to a mapping mode defined in fig. 2. At present, the DMR system defines three synchronization sequences: a voice synchronization sequence, a data synchronization sequence, and a reverse signaling synchronization sequence, for example, each synchronization sequence may be composed of 48 bits, and the symbol length after 4FSK modulation is 24, and fig. 3 shows a symbol conversion diagram of the synchronization sequence. Then, the synchronization sequence data (symbol structure) is subjected to "symbol-to-value" conversion to obtain synchronization sequence data (value structure) to be transmitted, and specifically, the synchronization sequence to be transmitted having a bit structure is converted into a value according to the conversion manner defined in fig. 9, where an abscissa represents an index related to a symbol, and an ordinate represents a corresponding value output, and each synchronization sequence subjected to value conversion has 24 values. Then, 0 is supplemented to the synchronous sequence data (numerical value structure) according to the oversampling multiple, and the synchronous sequence data (numerical value structure) is sent to a wireless channel after being filtered by an RRC (Radio Resource Control) filter, and the transmitting data is sent to a receiving end by the wireless channel; in the data processing flow of the baseband receiver, first, IQ (in-phase, quadrature) over-acquired data is obtained, the phase of the over-acquired data is calculated, a difference between the phases is obtained, then, a time domain synchronization signal is obtained through an RRC filter, then, carrier frequency offset estimation is performed on the time domain synchronization signal, and finally, demodulation and decoding are performed, thereby realizing a complete data processing flow of the baseband transmitter and the baseband receiver.
Disclosure of Invention
Based on the above technical background, the related frequency offset estimation algorithm is: in the receiver, first, a synchronization point index is obtained from a synchronization module; then, an over-sampling sequence r (n) is obtained in an RRC filter at the receiving end, where taking a synchronization sequence of 24 values sent by the transmitter as an example, the obtaining step of the over-sampling sequence r (n) is as follows: (1) supplementing oversampling points (namely numerical values) to the obtained synchronous sequence, for example, supplementing Nsample-1 0 after each numerical value in 24 numerical values to obtain a sequence senddata.0 containing 24Nsample numerical values, wherein Nsample is oversampling multiple, and Nsample > =2, (2) filtering the sequence senddata.0 by an RRC filter with two-stage order L in sequence to obtain an oversampling sequence R (n) with the length of 24Nsample + x L-2 numerical values; then, taking index as a starting point and oversampling multiple Nsample as an interval, and extracting 24 values from the oversampling sequence R (n) to form a candidate sequence C (m); finally, the average value of the extracted candidate sequences C (m) is taken as the frequency offset estimation value. In addition, parameters of the RRC filter are defined in the DMR system, but the oversampling multiples are different due to different receiver processing capabilities of different manufacturers. It can be seen that the above frequency offset estimation scheme estimates the carrier frequency offset based on the extraction value of the unsigned crosstalk point. The scheme only extracts 24 sampling point values, so the technical defects of few sampling point values and poor noise immunity are inevitable, and the scheme does not consider the interference of the values outside the synchronous sequence on the synchronous sequence due to the RRC filter, thereby influencing the precision of frequency offset estimation.
Since the conventional scheme has the technical defects of few effective values and poor noise immunity, and the precision of frequency offset estimation is greatly influenced, an improved method is needed.
Technical objects to be achieved by the present disclosure are not limited to solving the above problems, and other technical problems not mentioned will become apparent to those of ordinary skill in the art from the disclosed embodiments.
The technical scheme for solving the problems is as follows:
according to a first disclosed aspect, a frequency offset estimation method is provided for a receiver, the method comprising:
generating a local sequence based on the oversampling multiple and the synchronization sequence, the local sequence having a first preset number of values, and the first preset number being greater than the number of symbols of the synchronization sequence.
The method comprises the steps of obtaining preset synchronization points and over-sampling sequences, and extracting a second preset number of numerical values from the over-sampling sequences to form a first candidate sequence by taking the preset synchronization points as starting points, wherein the second preset number is equal to the first preset number.
And obtaining a frequency offset sequence according to the difference value of the first candidate sequence and the local sequence, and taking the average value of the frequency offset sequence as the output of frequency offset estimation.
Preferably, the generating the local sequence based on the oversampling multiple and the synchronization sequence includes:
and supplementing a third preset number of 0 after each numerical value point of the synchronous sequence to obtain an over-sampling vector, wherein the third preset number is related to the over-sampling multiple.
And filtering the over-sampling vector by an RRC (radio resource control) filter to obtain a filtering vector filteredData.
And sequentially taking a fourth preset number of numerical values as the local sequence by taking the filtering delay point as a starting point in the filtering vector filteredData.
Preferably, the acquiring a preset synchronization point and an over-sampling sequence, with the preset synchronization point as a starting point, extracts a second preset number of values from the over-sampling sequence to form a first candidate sequence, and then includes:
in the over-sampling sequence, a numerical value is extracted from the outer side of the starting point of the first candidate sequence to be used as the numerical value of a first interference point to be hard-judged, and a numerical value is extracted from the outer side of the end point of the first candidate sequence to be used as the numerical value of a second interference point to be hard-judged.
And performing interference cancellation on the first candidate sequence according to the numerical value of the first interference point and the numerical value of the second interference point to obtain a second candidate sequence.
And obtaining the frequency offset sequence according to the difference value of the second candidate sequence and the local sequence, and taking the average value of the frequency offset sequence as the output of frequency offset estimation.
Preferably, the performing interference cancellation on the first candidate sequence according to the value of the first interference point and the value of the second interference point to obtain a second candidate sequence includes:
and carrying out hard decision on the numerical value of the first interference point to obtain a hard decision value of the first interference point, and carrying out hard decision on the numerical value of the second interference point to obtain a hard decision value of the second interference point.
And calculating a first interference vector corresponding to the hard decision value of the first interference point and a second interference vector corresponding to the hard decision value of the second interference point.
And calculating to obtain the second candidate sequence according to the first candidate sequence, the first interference vector and the second interference vector.
Preferably, the calculating a first interference vector corresponding to the hard decision value of the first interference point and a second interference vector corresponding to the hard decision value of the first interference point includes:
the symbol length p for canceling the interfered is preset.
And obtaining the first interference vector and the second interference vector according to the symbol length p, the oversampling multiple, a starting interference symbol i1 of the first candidate sequence from the first interference point, a starting interference symbol i2 of the first candidate sequence from the second interference point, a value j1 of the interval between the first interference point and the synchronization point, a value j2 of the interval between the second interference point and the endpoint of the first candidate sequence, and after being convolved by an RRC filter, a value symbol 1 after the i1 th symbol has been oversampled on one side of a peak point and a value symbol2 after the i2 th symbol has been oversampled on the other side of the peak point.
Preferably, the obtaining the first interference vector and the second interference vector according to the symbol length p, the oversampling multiple, the starting interference symbol i1 of the first candidate sequence from the first interference point, the starting interference symbol i2 of the first candidate sequence from the second interference point, the value j1 between the first interference point and the synchronization point, the value j2 between the second interference point and the endpoint of the first candidate sequence, and after being convolved by the RRC filter, the value symbol 1 after the i1 th symbol oversampling on one side of the peak point and the value symbol2 after the i2 th symbol oversampling on the other side of the peak point includes:
taking the p as the number 2,Ia=[A'* symboli1，A'* symbol(i1+1)]，Ib=[B'* symboli2，B'* symbol(i2+1)]，
wherein a 'is a hard decision value of the first interference point, B' is a hard decision value of the second interference point, and Nsample is an oversampling multiple.
Preferably, the calculating the second candidate sequence according to the first candidate sequence, the first interference vector and the second interference vector includes:
determining preset lengths of the first interference vector and the second interference vector.
And in the first candidate sequence, extracting a first subsequence corresponding to the position of the first interference vector and the preset length, and extracting a second subsequence corresponding to the position of the second interference vector and the preset length, and reserving the rest sequences.
In the first candidate sequence, replacing the preset length value of the first subsequence with the difference value of the first subsequence and the first interference vector, and replacing the preset length value of the second subsequence with the difference value of the second subsequence and the second interference vector.
And taking the replaced sequence and the rest sequence as the second candidate sequence.
Preferably, the synchronization sequence is any one of a voice synchronization sequence, a data synchronization sequence and a reverse signaling synchronization sequence.
According to a second aspect of the disclosure, there is provided a frequency offset estimation apparatus, the apparatus including a local sequence generation module, a first candidate sequence generation module, and a frequency offset estimation output module, wherein:
the local sequence generation module is used for generating a local sequence based on the over-sampling multiple and the synchronous sequence, wherein the local sequence has a first preset number of numerical values, and the first preset number is larger than the number of the symbols of the synchronous sequence;
the first candidate sequence generation module is used for acquiring preset synchronization points and over-sampling sequences, and extracting a second preset number of numerical values from the over-sampling sequences to form a first candidate sequence by taking the preset synchronization points as starting points, wherein the second preset number is equal to the first preset number;
and the frequency offset estimation output module is used for obtaining a frequency offset sequence according to the difference value of the first candidate sequence and the local sequence, and taking the average value of the frequency offset sequence as the output of frequency offset estimation.
According to a third disclosed aspect, there is provided a frequency offset estimation apparatus comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the computer program, when executed by the processor, implementing the steps of the frequency offset estimation method as claimed in any one of the above.
According to a fourth aspect of the disclosure, a computer-readable storage medium is provided, on which a frequency offset estimation program is stored, which when executed by a processor implements the steps of the frequency offset estimation method according to any one of the above.
The method proposed in the present disclosure is advantageous in that more effective sampling values are utilized to improve the accuracy of frequency offset estimation, and meanwhile, the method of interference cancellation is used to further improve the accuracy of frequency offset estimation in consideration of the influence of the filter.
Drawings
The disclosure will be further described with reference to the accompanying drawings and examples, in which:
fig. 1 is a logic diagram illustrating a baseband transmitter and a baseband receiver in a communication system in accordance with the disclosed embodiments;
FIG. 2 is a schematic diagram illustrating 4FSK modulation in accordance with a disclosed embodiment;
FIG. 3 is a schematic diagram illustrating symbol transitions of a synchronization sequence in accordance with the disclosed embodiments;
FIG. 4 is a flow chart 1 illustrating frequency offset estimation in accordance with a disclosed embodiment;
FIG. 5 is another flow chart diagram 2 illustrating frequency offset estimation in accordance with the disclosed embodiments;
FIG. 6 is another flow chart diagram 3 illustrating frequency offset estimation in accordance with the disclosed embodiments;
FIG. 7 is another flow chart diagram 4 illustrating frequency offset estimation in accordance with the disclosed embodiments;
FIG. 8 is another flow chart diagram 5 illustrating frequency offset estimation in accordance with the disclosed embodiments;
FIG. 9 is a diagram illustrating a local sequence of frequency offset estimation in accordance with a disclosed embodiment;
FIG. 10 is a diagram illustrating interference cancellation numerical location of frequency offset estimation in accordance with the disclosed embodiments;
FIG. 11 is a diagram illustrating interference coefficients for frequency offset estimation in accordance with the disclosed embodiments;
FIG. 12 is a diagram illustrating a candidate sequence after interference cancellation for frequency offset estimation in accordance with the disclosed embodiments;
FIG. 13 is an apparatus block diagram illustrating frequency offset estimation in accordance with the disclosed embodiments;
FIG. 14 is a block diagram illustrating an apparatus for frequency offset estimation in accordance with the disclosed embodiments;
fig. 15 is a medium block diagram illustrating frequency offset estimation in accordance with the disclosed embodiments.
Detailed Description
Exemplary embodiments of the present disclosure are described in detail with reference to the accompanying drawings. The same reference numbers will be used throughout the drawings to refer to the same or like parts. A detailed description of known functions and configurations incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure.
Detailed descriptions of technical specifications that are well known in the art and that are not directly relevant to the present disclosure may be omitted to avoid obscuring the subject matter of the present disclosure. This is intended to omit unnecessary description in order to make the subject matter of the present disclosure clear.
It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a non-transitory computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the non-transitory computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
Further, various block diagrams may illustrate modules, segments, or portions of code comprising at least one or more executable instructions for implementing the specified logical function(s). Further, it should be noted that in several modifications, the functions of the blocks may be performed in a different order. For example, two consecutive blocks may be executed substantially concurrently, or they may be executed in reverse order, depending on their functionality.
Fig. 4 is a flow chart 1 illustrating frequency offset estimation in accordance with a disclosed embodiment. The embodiment provides a frequency offset estimation method for a receiver, which comprises the following steps:
s1, generating a local sequence based on the over-sampling multiple and the synchronous sequence, wherein the local sequence has a first preset number of values, and the first preset number is larger than the number of the symbols of the synchronous sequence.
Specifically, the local sequence d (m) is obtained as follows: (1) supplementing a third preset number of 0 after each numerical value point of the synchronous sequence to obtain an over-sampling vector senddata.l, wherein the third preset number is related to an over-sampling multiple Nsample; (2) filtering the over-sampling vector senddata.l by an RRC (radio resource control) filter to obtain a filter vector filteredData; (3) and sequentially taking a fourth preset number of numerical values as the local sequence by taking the filtering delay point as a starting point in the filtering vector filteredData. Optionally, taking a synchronization sequence with 24 values as an example, the step of obtaining the local sequence d (m) is further described: (1) supplementing acquired values to the obtained synchronous sequence, for example, supplementing Nsample-1 0 to each of 24 values to obtain a vector senddata.1 containing 24Nsample values, (2) sequentially filtering the vector senddata.1 by two stages of RRC filters with the order of L to obtain a filter vector filterdata with the length of 24Nsample + x L-2 values, and (3) sequentially taking x L +1 as a starting point to obtain a first preset number of values from the filter vector filterdata, wherein the first preset number is greater than the number (24) of the synchronous sequence, for example, the first preset number is 23Nsample +1 values to obtain a local sequence D (m).
The order L of the RRC filter is determined by the characteristics of the RRC filter. It is easy to understand that when different RRC filters are used, the corresponding orders L are different; 24Nsample + x L-2 denotes the length of the filter vector filteredData passing through the two RRC filters of order L, and x L +1 denotes a filter delay point, where x denotes the number of filters passing through.
The length of the local sequence d (m) is 23Nsample +1, which has the beneficial effects that the data of the filter vector filteredData terminal can be avoided being obtained (the data of the filter vector filteredData terminal is known to be interfered to a greater extent) while more sampling point values can be met, and the interference can be reduced, but the length of the local sequence d (m) is not limited to 23Nsample + 1.
S2, acquiring preset synchronization points and over-sampling sequences, and taking the preset synchronization points as starting points, extracting a second preset number of numerical values from the over-sampling sequences to form a first candidate sequence, wherein the second preset number is equal to the first preset number.
Specifically, the first candidate sequence c (m) is obtained as follows: (1) acquiring a preset synchronization point index and an over-sampling sequence R (n); (2) sequentially extracting a second predetermined number of values from the oversampled sequence R (n) by a predetermined synchronization point index to form a first candidate sequence C (m). Optionally, as described in the above example, taking a sync sequence with 24 values as an example, if the obtained local sequence d (m) has 23Nsample +1 values, the corresponding first candidate sequence c (m) is also 23Nsample +1 values.
S3, obtaining a frequency offset sequence according to the difference value between the first candidate sequence and the local sequence, and taking the average value of the frequency offset sequence as the output of the frequency offset estimation.
In this embodiment, a frequency offset sequence f (m) is obtained from a difference between the first candidate sequence c (m) and the local sequence d (m), and an average value of the frequency offset sequence f (m) is used as an output of the frequency offset estimation.
In this embodiment, the synchronization module obtains the start point index of this embodiment, and the synchronization module includes a time domain synchronization function module.
In this embodiment, the RRC filter acquires the oversubsampling sequence r (n) of this embodiment at the receiving end.
In the present embodiment, the calculation formula of the frequency offset sequence f (m) is f (m) = c (m) -d (m).
The frequency offset estimation method provided by the embodiment has the beneficial effects that by combining the oversampling multiple, the sampling point value of the local sequence is increased, and the accuracy and precision of frequency offset estimation are improved.
Also, in combination with the effect of the RRC filter, in order to further improve the accuracy and precision of the frequency offset estimation, an interference cancellation method is disclosed below.
Fig. 5 is another flow chart 2 illustrating frequency offset estimation in accordance with a disclosed embodiment. Based on the above embodiment, in order to implement interference cancellation, after acquiring a preset synchronization point and an over-sampling sequence, and taking the preset synchronization point as a starting point, and extracting a second preset number of values from the over-sampling sequence to form a first candidate sequence, the method further includes the following steps:
s21, in the over-sampling sequence, extracting a value from the outside of the start point of the first candidate sequence as the value of the first interference point to be hard-decided, and extracting a value from the outside of the end point of the first candidate sequence as the value of the second interference point to be hard-decided.
Optionally, the numerical value of the first interference point and the numerical value of the second interference point are respectively recorded as an a-point value and a B-point value, in the over-sampling sequence r (n), the numerical value of the index-Nsample is extracted as the a-point value to be hard-decided, and in the over-sampling sequence r (n), the numerical value of the index +24Nsample +1 is extracted as the B-point value to be hard-decided.
S22, performing interference cancellation on the first candidate sequence according to the numerical value of the first interference point and the numerical value of the second interference point to obtain a second candidate sequence.
As described in the above example, the first candidate sequence C (m) is subjected to interference cancellation according to the a-point value and the B-point value, so as to obtain a second candidate sequence C' (m).
And S23, obtaining the frequency offset sequence according to the difference value of the second candidate sequence and the local sequence, and taking the average value of the frequency offset sequence as the output of frequency offset estimation.
As described in the above example, the difference between the second candidate sequence C' (m) and the local sequence d (m) is used to obtain the frequency offset sequence f (m), and the average value of the frequency offset sequence f (m) is used as the output of the frequency offset estimation.
Fig. 6 is another flow chart diagram 3 illustrating frequency offset estimation in accordance with a disclosed embodiment. Based on the above embodiment, how to perform interference cancellation on the first candidate sequence according to the value of the first interference point and the value of the second interference point to obtain a second candidate sequence specifically includes the following steps:
s24, carrying out hard decision on the numerical value of the first interference point to obtain a hard decision value of the first interference point, and carrying out hard decision on the numerical value of the second interference point to obtain a hard decision value of the second interference point.
S25, calculating a first interference vector corresponding to the hard decision value of the first interference point and a second interference vector corresponding to the hard decision value of the second interference point.
S26, calculating the second candidate sequence according to the first candidate sequence, the first interference vector and the second interference vector.
In this embodiment, the first interference point is denoted as point a, the second interference point is denoted as point B, a 'is a hard decision value of the first interference point, and B' is a hard decision value of the second interference point. First, hard decision of the a-point value will be described as an example.
If A > 2.
Then a' = 3.
Otherwise if a > = 0.
Then a' = 1.
Otherwise if a > = -2.
Then a' = -1.
Otherwise a' = -3.
In this embodiment, the B point value is hard-decided in the same manner to obtain a corresponding B' point value.
Fig. 10 is a diagram illustrating the location of interference cancellation values for frequency offset estimation in accordance with the disclosed embodiment, with data a making hard decisions on the left and data B making hard decisions on the right. In this embodiment, the first interference vector is regarded as an interference vector Ia, the second interference vector is regarded as an interference vector Ib, and the corresponding interference vector Ia and the corresponding interference vector Ib are obtained by respectively calculating based on the a 'point value and the B' point value obtained by the hard decision; then, in the first candidate sequence C (m), interference cancellation is performed according to the interference vector Ia and the interference vector Ib, so as to obtain a second candidate sequence C' (m) after interference cancellation.
Fig. 7 is another flow chart diagram 4 illustrating frequency offset estimation in accordance with a disclosed embodiment. Based on the above embodiment, how to calculate the interference vector Ia corresponding to the a 'point value and the interference vector Ib corresponding to the B' point value is further described below, and the specific steps include:
and S27, presetting symbol length p for counteracting the interfered interference.
S28, obtaining the first interference vector and the second interference vector according to the symbol length p, the oversampling multiple, the initial interference symbol i1 of the first candidate sequence from the first interference point, the initial interference symbol i2 of the first candidate sequence from the second interference point, the value j1 between the first interference point and the synchronization point, and the value j2 between the second interference point and the endpoint of the first candidate sequence, and after being convolved by the RRC filter, taking the value symbolli 1 after the i1 th symbol has been extracted on one side of the peak point, and the value symbolli 2 after the i2 th symbol has been extracted on the other side of the peak point.
In this embodiment, first, p interfered symbols are determined to be cancelled, for example, the value of p may be 1, 2, …, 5, and the value of p may be set according to actual requirements.
For example, when the interference vector Ia is calculated based on the a' point value:
if p takes one symbol, the interference vector Ia = [ a'. symbol 1 ].
If p takes two symbols, the interference vector Ia = [ a '× symbol 1, a' × symbol (i1+1) ].
If p takes three symbols, the interference vector Ia = [ a ' × symbol 1, a ' × symbol (i1+1), a ' × symbol (i1+2) ].
For another example, when the interference vector Ib is calculated based on the B' point value:
if p takes one symbol, the interference vector Ib = [ B'. symbol2 ].
If p takes two symbols, the interference vector Ib = [ B '. symbol i2, B'. symbol (i2+1) ].
If p takes three symbols, the interference vector Ib = [ B ' × symbol i2, B ' × symbol (i2+1), B ' × symbol (i2+2) ].
i1 represents the starting interference symbol of the point A to the first candidate sequence, and i2 represents the starting interference symbol of the point B to the first candidate sequence. As shown in fig. 11, which is a schematic diagram of the interference coefficients of the a-point value (or the B-point value), it can be known from fig. 11 that the interference of the a-point value (or the B-point value) on the first candidate sequence is in units of symbols (i.e., Nsample numbers); thus, there are
。
In the above calculation formula, j1 represents the number of values between the a point and the synchronization point in the over-sampling sequence r (n), and j2 represents the number of values between the B point and the endpoint of the first candidate sequence in the over-sampling sequence r (n), specifically, please refer to the number j1 between the a point and the synchronization point and the number j2 between the B point and the endpoint of the first candidate sequence in the over-sampling sequence r (n) shown in fig. 10.
Preferably, p takes two symbols, and when j1= Nsample, i1=2, then the interference vector Ia = [ a '× symbol2, a' × symbol3 ].
By analogy, the present embodiment may take the interference vectors of multiple symbols, where the length of Ia is equal to p × Nsample, and the value of the oversampling multiple Nsample may be determined according to actual requirements.
FIG. 11 is a diagram illustrating interference coefficients for frequency offset estimation in accordance with the disclosed embodiments, wherein the ordinate represents the magnitude of the interference coefficients. In this embodiment, symbolol 1 (or symbolol 2) is convolved by an RRC filter, and the sampled value of the i1 (or i 2) th symbol is taken on the peak side.
For example, when the oversampling factor is 5, taking point a as an example, a graph after convolution by two RRC filters is shown in fig. 11, where interference values of different symbols of a' are as follows:
in this embodiment, the interference vector Ib is calculated in the same manner, which is not described herein again.
Optionally, in this embodiment, the number of the selected interference points is not limited to two interference points, and three or more interference points may be set according to an actual interference cancellation requirement. Meanwhile, in the present embodiment, the intervals of the two selected interference points with respect to the start point and the end point of the first candidate sequence, respectively, are not limited to the specific intervals listed above, and may be set according to the actual interference cancellation requirement.
Fig. 8 is another flow chart diagram 5 illustrating frequency offset estimation in accordance with a disclosed embodiment. Based on the above embodiment, to further explain how to calculate the second candidate sequence C' (m) according to the first candidate sequence C (m), the interference vector Ia, and the interference vector Ib, the specific steps include:
s301, determining preset lengths of the first interference vector and the second interference vector.
In this embodiment, in the first candidate sequence C (m), alternative sequences corresponding to the interference vector Ia and the interference vector Ib are respectively determined, and a sequence after the alternative processing is taken as the second candidate sequence C' (m).
In this embodiment, as known from P × Nsample, when P =2 and Nsample =5, the preset length n of the interference vector Ia at this time is 10.
In this embodiment, the value n of the preset length may be changed according to actual requirements.
In this embodiment, in the first candidate sequence C (m), alternative sequences corresponding to the interference vector Ia and the interference vector Ib are determined based on the numerical lengths of the interference vector Ia and the interference vector Ib, respectively, and the sequences after the alternative processing are taken as the second candidate sequence C' (m).
S302, in the first candidate sequence, extracting a first subsequence corresponding to the position of the first interference vector and the preset length, and extracting a second subsequence corresponding to the position of the second interference vector and the preset length, and reserving the remaining sequences.
As described in the above example, in the first candidate sequence C (m), a subsequence ca (n) corresponding to the position and the predetermined length of the interference vector Ia is extracted, and a subsequence cb (n) corresponding to the position and the predetermined length of the interference vector Ib is extracted, and the remaining sequences are denoted as sequence C0 (y).
S303, in the first candidate sequence, replacing preset length values of the first subsequence with difference values of the first subsequence and the first interference vector, and replacing preset length values of the second subsequence with difference values of the second subsequence and the second interference vector.
In the first candidate sequence c (m), n values of the subsequence ca (n) are replaced with values obtained by ca (n) -Ia, respectively, and n values of the subsequence cb (n) are replaced with values obtained by cb (n) -Ib, respectively, as described in the above example.
And S304, taking the replaced sequence and the rest sequences as the second candidate sequence.
As described in the above example, the replaced sequence and the sequence C0 (y) are taken as the second candidate sequence C' (m).
In this embodiment, as described in the above example, when n is 10, a subsequence Ca (10) is taken from the first candidate sequence c (m), and the subsequence Ca (10) corresponds to the position and length of the interference vector Ia; similarly, another subsequence Cb (10) corresponding to the position and length of the interference vector Ib is taken out; and the remainder of the first candidate sequence C (m) is denoted as C0 (y).
Fig. 12 is a diagram illustrating a candidate sequence after interference cancellation for frequency offset estimation according to a disclosed embodiment. It can be seen that, in the first candidate sequence c (m), 10 values of the subsequence Ca (10) are replaced with values obtained by Ca (10) -Ia, respectively, and similarly, 10 values of the subsequence Cb (10) are replaced with values obtained by Cb (10) -Ib, respectively. In this way, the second candidate sequence C '(m) after the interference cancellation is obtained, that is, the second candidate sequence C' (m) is output after the interference cancellation.
Optionally, in this embodiment, the synchronization sequence is any one of a voice synchronization sequence, a data synchronization sequence, and a reverse signaling synchronization sequence.
According to the frequency offset estimation method, the number of the sampling points is increased, meanwhile, the interference of the number outside the synchronous sequence to the synchronous sequence is considered, the interference vector is generated by calculating the interference points and the interference is offset, and the accuracy and precision of frequency offset estimation are further improved.
Fig. 13 is an apparatus block diagram illustrating frequency offset estimation in accordance with the disclosed embodiments. Based on the foregoing embodiments, the present disclosure further provides a frequency offset estimation apparatus 100, where the frequency offset estimation apparatus 100 includes a local sequence generation module 10, a first candidate sequence generation module 20, and a frequency offset estimation output module 30, where:
the local sequence generating module 10 is configured to generate a local sequence based on the oversampling multiple and the synchronization sequence, where the local sequence has a first preset number of values, and the first preset number is greater than the number of symbols of the synchronization sequence.
The first candidate sequence generating module 20 is configured to obtain a preset synchronization point and an over-sampling sequence, and extract a second preset number of values from the over-sampling sequence to form a first candidate sequence with the preset synchronization point as a starting point, where the second preset number is equal to the first preset number.
The frequency offset estimation output module 30 is configured to obtain a frequency offset sequence according to a difference between the first candidate sequence and the local sequence, and use an average value of the frequency offset sequence as an output of frequency offset estimation.
In this embodiment, a third preset number of 0 is added after each value point of the synchronization sequence to obtain an over-sampling vector, where the third preset number is related to the over-sampling multiple.
And filtering the over-sampling vector by an RRC (radio resource control) filter to obtain a filtering vector filteredData.
And sequentially taking a fourth preset number of numerical values as the local sequence by taking the filtering delay point as a starting point in the filtering vector filteredData.
In this embodiment, in the over-sampling sequence, a value is extracted from the outside of the start point of the first candidate sequence as the value of the first interference point to be hard-decided, and a value is extracted from the outside of the end point of the first candidate sequence as the value of the second interference point to be hard-decided.
And performing interference cancellation on the first candidate sequence according to the numerical value of the first interference point and the numerical value of the second interference point to obtain a second candidate sequence.
And obtaining the frequency offset sequence according to the difference value of the second candidate sequence and the local sequence, and taking the average value of the frequency offset sequence as the output of frequency offset estimation.
In this embodiment, the hard decision is performed on the value of the first interference point to obtain a hard decision value of the first interference point, and the hard decision is performed on the value of the second interference point to obtain a hard decision value of the second interference point.
And calculating a first interference vector corresponding to the hard decision value of the first interference point and a second interference vector corresponding to the hard decision value of the second interference point.
And calculating to obtain the second candidate sequence according to the first candidate sequence, the first interference vector and the second interference vector.
In the present embodiment, the symbol length p for canceling the interfered is preset.
And obtaining the first interference vector and the second interference vector according to the symbol length p, the oversampling multiple, a starting interference symbol i1 of the first candidate sequence from the first interference point, a starting interference symbol i2 of the first candidate sequence from the second interference point, a value j1 of the interval between the first interference point and the synchronization point, a value j2 of the interval between the second interference point and the endpoint of the first candidate sequence, and after being convolved by an RRC filter, a value symbol 1 after the i1 th symbol has been oversampled on one side of a peak point and a value symbol2 after the i2 th symbol has been oversampled on the other side of the peak point.
In this embodiment, when the symbol length p takes 2, the first interference vector Ia = [ a '× symbol 1, a' × symbol (i1+1) ], and the second interference vector Ib = [ B '× symbol2, B' × symbol (i2+1) ], where a 'is a hard-decision value of the first interference point and B' is a hard-decision value of the second interference point.
In this embodiment, the preset lengths of the first interference vector and the second interference vector are determined.
And in the first candidate sequence, extracting a first subsequence corresponding to the position of the first interference vector and the preset length, and extracting a second subsequence corresponding to the position of the second interference vector and the preset length, and reserving the rest sequences.
In the first candidate sequence, replacing the preset length value of the first subsequence with the difference value of the first subsequence and the first interference vector, and replacing the preset length value of the second subsequence with the difference value of the second subsequence and the second interference vector.
And taking the replaced sequence and the rest sequence as the second candidate sequence.
In this embodiment, the synchronization sequence is any one of a voice synchronization sequence, a data synchronization sequence, and a reverse signaling synchronization sequence.
It should be noted that the device embodiment and the method embodiment belong to the same concept, and specific implementation processes thereof are detailed in the method embodiment, and technical features in the method embodiment are correspondingly applicable in the device embodiment, which is not described herein again.
Fig. 14 is a block diagram illustrating an apparatus for frequency offset estimation in accordance with a disclosed embodiment. Based on the foregoing embodiments, the present disclosure further provides a frequency offset estimation apparatus 200, where the apparatus 200 includes a memory 40, a processor 50, and a computer program 60 stored on the memory 40 and executable on the processor, and when executed by the processor, the computer program 60 implements the steps of the frequency offset estimation method according to any one of the above embodiments.
It should be noted that the device embodiment and the method embodiment belong to the same concept, and specific implementation processes thereof are detailed in the method embodiment, and technical features in the method embodiment are correspondingly applicable in the device embodiment, which is not described herein again.
Fig. 15 is a medium block diagram illustrating frequency offset estimation in accordance with the disclosed embodiments. Based on the foregoing embodiments, the present disclosure further provides a computer-readable storage medium 300, where the computer-readable storage medium 300 stores a frequency offset estimation program 70, and when executed by a processor, the frequency offset estimation program 70 implements the steps of the frequency offset estimation method according to any of the foregoing embodiments.
It should be noted that the media embodiment and the method embodiment belong to the same concept, and specific implementation processes thereof are detailed in the method embodiment, and technical features in the method embodiment are correspondingly applicable in the media embodiment, which is not described herein again.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (11)
1. A frequency offset estimation method applied to a receiving end is characterized by comprising the following steps:
generating a local sequence based on the over-sampling multiple and the synchronous sequence, wherein the local sequence has a first preset number of numerical values, and the first preset number is larger than the number of symbols of the synchronous sequence;
acquiring preset synchronization points and over-sampling sequences, and extracting a second preset number of numerical values from the over-sampling sequences to form a first candidate sequence by taking the preset synchronization points as starting points, wherein the second preset number is equal to the first preset number;
and obtaining a frequency offset sequence according to the difference value of the first candidate sequence and the local sequence, and taking the average value of the frequency offset sequence as the output of frequency offset estimation.
2. The frequency offset estimation method of claim 1 wherein said generating a local sequence based on an oversampling multiple and a synchronization sequence comprises:
supplementing a third preset number of 0 after each numerical value point of the synchronous sequence to obtain an over-sampling vector, wherein the third preset number is related to the over-sampling multiple;
filtering the over-sampling vector by an RRC (radio resource control) filter to obtain a filter vector filteredData;
and sequentially taking a fourth preset number of numerical values as the local sequence by taking the filtering delay point as a starting point in the filtering vector filteredData.
3. The frequency offset estimation method according to claim 1 or 2, wherein the obtaining of the predetermined synchronization point and the over-sampling sequence takes the predetermined synchronization point as a starting point, and a second predetermined number of values are extracted from the over-sampling sequence to form a first candidate sequence, and then the method comprises:
in the over-sampling sequence, extracting a numerical value from the outer side of the starting point of the first candidate sequence as the numerical value of a first interference point to be hard-judged, and extracting a numerical value from the outer side of the end point of the first candidate sequence as the numerical value of a second interference point to be hard-judged;
performing interference cancellation on the first candidate sequence according to the numerical value of the first interference point and the numerical value of the second interference point to obtain a second candidate sequence;
and obtaining the frequency offset sequence according to the difference value of the second candidate sequence and the local sequence, and taking the average value of the frequency offset sequence as the output of frequency offset estimation.
4. The frequency offset estimation method according to claim 3, wherein the performing interference cancellation on the first candidate sequence according to the value of the first interference point and the value of the second interference point to obtain a second candidate sequence comprises:
performing hard decision on the numerical value of the first interference point to obtain a hard decision value of the first interference point, and performing hard decision on the numerical value of the second interference point to obtain a hard decision value of the second interference point;
calculating a first interference vector corresponding to the hard decision value of the first interference point and a second interference vector corresponding to the hard decision value of the second interference point;
and calculating to obtain the second candidate sequence according to the first candidate sequence, the first interference vector and the second interference vector.
5. The frequency offset estimation method according to claim 4, wherein said calculating a first interference vector corresponding to the hard decision value of the first interference point and a second interference vector corresponding to the hard decision value of the first interference point comprises:
presetting symbol length p for counteracting interfered;
and obtaining the first interference vector and the second interference vector according to the symbol length p, the oversampling multiple, a starting interference symbol i1 of the first candidate sequence from the first interference point, a starting interference symbol i2 of the first candidate sequence from the second interference point, a value j1 of the first interference point spaced from a synchronization point, a value j2 of the second interference point spaced from an endpoint of the first candidate sequence, and a value symbol 1 after the i1 th symbol has been acquired on one side of a peak point and a value symbol2 after the i2 th symbol has been acquired on the other side of the peak point after being convolved by an RRC filter.
6. The frequency offset estimation method according to claim 5, wherein the obtaining the first interference vector and the second interference vector according to the symbol length p, the oversampling multiple, the starting interference symbol i1 of the first candidate sequence for the first interference point, the starting interference symbol i2 of the second interference point for the first candidate sequence, the value j1 between the first interference point and the synchronization point, the value j2 between the second interference point and the end point of the first candidate sequence, and the value symbol 1 after the i1 th symbol oversampling on one side of the peak point and the value symbol2 after the i2 th symbol oversampling on the other side of the peak point after the RRC filter convolution comprises:
p is 2, Ia = [ A '. symbol 1, A'. symbol (i1+1)]，Ib=[B'* symboli2，B'* symbol(i2+1)]，
Wherein a 'is a hard decision value of the first interference point, B' is a hard decision value of the second interference point, and Nsample is an oversampling multiple.
7. The frequency offset estimation method according to any of claims 4-6, wherein said calculating the second candidate sequence according to the first candidate sequence, the first interference vector and the second interference vector comprises:
determining preset lengths of the first interference vector and the second interference vector;
in the first candidate sequence, extracting a first subsequence corresponding to the position of the first interference vector and the preset length, and extracting a second subsequence corresponding to the position of the second interference vector and the preset length, and reserving the rest sequences;
in the first candidate sequence, replacing preset length values of the first subsequence with difference values of the first subsequence and the first interference vector, and replacing preset length values of the second subsequence with difference values of the second subsequence and the second interference vector;
and taking the replaced sequence and the rest sequence as the second candidate sequence.
8. The frequency offset estimation method according to claim 7, wherein said synchronization sequence is any one of a voice synchronization sequence, a data synchronization sequence and a reverse signaling synchronization sequence.
9. A frequency offset estimation apparatus, comprising a local sequence generation module, a first candidate sequence generation module, and a frequency offset estimation output module, wherein:
the local sequence generation module is used for generating a local sequence based on the over-sampling multiple and the synchronous sequence, wherein the local sequence has a first preset number of numerical values, and the first preset number is larger than the number of the symbols of the synchronous sequence;
the first candidate sequence generation module is used for acquiring preset synchronization points and over-sampling sequences, and extracting a second preset number of numerical values from the over-sampling sequences to form a first candidate sequence by taking the preset synchronization points as starting points, wherein the second preset number is equal to the first preset number;
and the frequency offset estimation output module is used for obtaining a frequency offset sequence according to the difference value of the first candidate sequence and the local sequence, and taking the average value of the frequency offset sequence as the output of frequency offset estimation.
10. A frequency offset estimation apparatus, characterized in that the apparatus comprises a memory, a processor and a computer program stored on the memory and executable on the processor, the computer program, when executed by the processor, implementing the steps of the frequency offset estimation method according to any of claims 1 to 8.
11. A computer-readable storage medium, characterized in that the computer-readable storage medium has stored thereon a frequency offset estimation program, which when executed by a processor implements the steps of the frequency offset estimation method according to any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111077899.3A CN113542181B (en) | 2021-09-15 | 2021-09-15 | Frequency offset estimation method, device, equipment and computer readable storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111077899.3A CN113542181B (en) | 2021-09-15 | 2021-09-15 | Frequency offset estimation method, device, equipment and computer readable storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113542181A true CN113542181A (en) | 2021-10-22 |
| CN113542181B CN113542181B (en) | 2021-12-07 |
Family
ID=78092589
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111077899.3A Active CN113542181B (en) | 2021-09-15 | 2021-09-15 | Frequency offset estimation method, device, equipment and computer readable storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113542181B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101312445A (en) * | 2008-05-12 | 2008-11-26 | 北京创毅视讯科技有限公司 | Decimal frequency bias estimation method and apparatus of receiver |
| CN103416005A (en) * | 2011-03-10 | 2013-11-27 | 国际商业机器公司 | On-the-fly compensation of sampling frequency and phase offset at side of receiver executing ultra high-speed wireless communication |
| CN104242983A (en) * | 2013-06-09 | 2014-12-24 | 大唐联诚信息***技术有限公司 | Method and device for improving frequency synchronization accuracy |
| CN105245303A (en) * | 2015-08-28 | 2016-01-13 | 北京理工大学 | High-speed burst demodulation synchronization system |
| CN106487494A (en) * | 2015-09-02 | 2017-03-08 | 华为技术有限公司 | The synchronous method of signal and the device of signal synchronization |
| CN108199993A (en) * | 2017-12-13 | 2018-06-22 | 浙江大华技术股份有限公司 | A kind of synchronous head inspecting method, device, electronic equipment and readable storage medium storing program for executing |
| CN109936403A (en) * | 2017-12-19 | 2019-06-25 | 成都鼎桥通信技术有限公司 | The synchronization of multiaerial system and method for reseptance and receiving device |
| CN112865882A (en) * | 2021-01-19 | 2021-05-28 | 南京中新赛克科技有限责任公司 | Anti-frequency-deviation DMR interphone signal rapid identification method |
| CN113141245A (en) * | 2021-06-22 | 2021-07-20 | 中国人民解放军国防科技大学 | Time-frequency synchronization method, system, equipment and readable storage medium |
-
2021
- 2021-09-15 CN CN202111077899.3A patent/CN113542181B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101312445A (en) * | 2008-05-12 | 2008-11-26 | 北京创毅视讯科技有限公司 | Decimal frequency bias estimation method and apparatus of receiver |
| CN103416005A (en) * | 2011-03-10 | 2013-11-27 | 国际商业机器公司 | On-the-fly compensation of sampling frequency and phase offset at side of receiver executing ultra high-speed wireless communication |
| CN104242983A (en) * | 2013-06-09 | 2014-12-24 | 大唐联诚信息***技术有限公司 | Method and device for improving frequency synchronization accuracy |
| CN105245303A (en) * | 2015-08-28 | 2016-01-13 | 北京理工大学 | High-speed burst demodulation synchronization system |
| CN106487494A (en) * | 2015-09-02 | 2017-03-08 | 华为技术有限公司 | The synchronous method of signal and the device of signal synchronization |
| CN108199993A (en) * | 2017-12-13 | 2018-06-22 | 浙江大华技术股份有限公司 | A kind of synchronous head inspecting method, device, electronic equipment and readable storage medium storing program for executing |
| CN109936403A (en) * | 2017-12-19 | 2019-06-25 | 成都鼎桥通信技术有限公司 | The synchronization of multiaerial system and method for reseptance and receiving device |
| CN112865882A (en) * | 2021-01-19 | 2021-05-28 | 南京中新赛克科技有限责任公司 | Anti-frequency-deviation DMR interphone signal rapid identification method |
| CN113141245A (en) * | 2021-06-22 | 2021-07-20 | 中国人民解放军国防科技大学 | Time-frequency synchronization method, system, equipment and readable storage medium |
Non-Patent Citations (1)
| Title |
|---|
| 钟烈: "基于DMR的4CPFSK基带信号处理技术研究和芯片设计实现", 《中国优秀硕士学位论文全文数据库》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113542181B (en) | 2021-12-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6657277B2 (en) | Transmission device | |
| EP3264701B1 (en) | Frequency shift keying (fsk) demodulators | |
| EP3512170B1 (en) | Circuit structure for efficiently demodulating fsk signal in wireless charging device | |
| JP2007528132A (en) | Method and apparatus for suppressing co-channel interference in receiving apparatus | |
| WO2005041429A1 (en) | Multi-pass interference reduction in a gsm communication system | |
| WO2004073185A2 (en) | Reducing interference in a gsm communication system | |
| EP3185500B1 (en) | Frequency offset and modulation index estimation in bluetooth low energy, ble, communication devices | |
| EP2179552A2 (en) | Interference suppression method and apparatus | |
| CN104904171B (en) | Method and apparatus for demodulating Q state GFSK modulated signals | |
| EP1228611A1 (en) | Radio receiver with two stages of dc offset correction, synchronisation and channel estimation | |
| KR20050073441A (en) | Apparatus and methods for suppression of interference | |
| KR20100089166A (en) | Apparatus and method for interference cancellation in mobile full duplex relay | |
| CN113556202B (en) | Time domain synchronization point acquisition method, device, equipment and storage medium | |
| Liu et al. | Low-complexity single-channel blind separation of co-frequency coded signals | |
| IL276847A (en) | Receiver and method for receiving a combination signal using separate in-phase and quadrature components | |
| CN113542181B (en) | Frequency offset estimation method, device, equipment and computer readable storage medium | |
| CN107171995B (en) | GMSK signal generation device and method, and signal detection device and method | |
| JP4163578B2 (en) | Digital receiver | |
| CN111212006B (en) | Signal demodulation system and demodulation method | |
| JP2003502910A (en) | Method and system for binary information detection in the presence of slowly changing disturbances | |
| CN111083083B (en) | OFDM system receiving end phase compensation method and system | |
| JP4408446B2 (en) | Method for transmitting and receiving QAM signals with low signal-to-noise ratio | |
| JPH11154925A (en) | Digital transmitter | |
| JP6603252B2 (en) | Wireless communication apparatus and reception processing method | |
| JP2006005396A (en) | Equalizer and demodulator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: Frequency offset estimation method, apparatus, device and computer-readable storage medium Effective date of registration: 20220809 Granted publication date: 20211207 Pledgee: China Co. truction Bank Corp Guangzhou Panyu branch Pledgor: Guangzhou huiruisitong Technology Co.,Ltd. Registration number: Y2022440000191 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PP01 | Preservation of patent right |
Effective date of registration: 20230207 Granted publication date: 20211207 |
|
| PP01 | Preservation of patent right | ||
| PD01 | Discharge of preservation of patent |
Date of cancellation: 20240402 Granted publication date: 20211207 |
|
| PD01 | Discharge of preservation of patent |