CN108736931A - A kind of signal synchronizing method and device - Google Patents
A kind of signal synchronizing method and device Download PDFInfo
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- CN108736931A CN108736931A CN201710245743.9A CN201710245743A CN108736931A CN 108736931 A CN108736931 A CN 108736931A CN 201710245743 A CN201710245743 A CN 201710245743A CN 108736931 A CN108736931 A CN 108736931A
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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
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/0413—MIMO systems
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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
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Abstract
Disclosed herein is a kind of signal synchronizing method and devices.The signal synchronizing method includes：It is locked in automatic growth control AGC unit and receives signal that signal Shi Duige roads reception antenna receives into line delay auto-correlation processing, it receives signal and the road and receives the corresponding reference thresholding of signal and be compared treated on road delay first time length Hou Jiangge, determine whether to complete thick synchronization according to each road comparison result；After thick synchronously complete, the local cross correlation process of signal progress is received to each road, the result of each road cross correlation process is weighted cumulative and filtering, maximum value is searched for from filtered signal, judgement completion essence is synchronous when searching maximum value.The technical solution of this paper can ensure to receive positioning accuracy when signal synchronizes in multi-input multi-output system, and reduce the complexity of calculating.
Description
Technical field
The present invention relates to wireless communication technology field more particularly to a kind of signal synchronizing methods and device.
Background technology
The performance of simultaneous techniques is directly related to the performance of entire communication system.It may be said that without accurate synchronized algorithm,
It is impossible to carry out reliable data transmission, it is the premise of information transmitting.And for orthogonal frequency division multiplexing
For (Orthogonal Frequency Division Multiplexing, abbreviation OFDM) system, system is for synchronous
It is required that very high.Because of inter-carrier interference (Inter Channel Interference, abbreviation that various synchronous errors introduce
ICI), intersymbol interference (inter symbol interference, abbreviation ISI) can make receiver be unable to properly receive number
According to, and can also destroy the orthogonality of each subcarrier in ofdm system.
As shown in Figure 1, in a common ofdm system receiver, automatic growth control (Automatic Gain
Control, AGC) after unit (301) triggering locking receives signal, the signal that will be received from each road antenna (302) is sent into modulation
It is that symbol synchronizer (304) carries out positioning synchronous first in Modem in demodulator (Modem) (303).Symbol synchronizer is fixed
The result of bit synchronization is that Fast Fourier Transform (FFT) (Fast Fourier Transformation, abbreviation FFT) unit (305) carries
For a reference point, next series of operation (for example, demodulation) is thus allowed for.Not influence next demodulation,
Sign synchronization positioning accuracy must be within certain zone of reasonableness.
Symbol location synchronizes the initial position for being just to determine OFDM symbol, i.e., the initial position of each FFT windows.Such as attached drawing
Shown in 2, symbol location, which synchronizes, is likely to occur four kinds of situations：1) FFT windows 1 (Window1) expression timing estimation point is correct,
There is no deviation, demodulates the data come and should also be correct；3) FFT windows 2 (Window2) indicate that timing estimation point is fallen at this
In the cyclic prefix (Cyclic Prefix, CP) of symbol, and it is ahead of best timing point；3) FFT windows 3 (Window3) indicate
Timing estimation point is fallen in the cyclic prefix of next symbol, and lags behind best timing point；4) FFT windows 4 (Window4) table
Show that timing estimation point is fallen in the data portion of previous symbol, and is ahead of the cyclic prefix of this symbol.
Above-mentioned four kinds of situations, the first is ideal situation, will not cause symbol location error；It is differed with ideal point for second
In the case of less, the deviations of introducing can be restored by balanced device, but if when differing larger, can influence to believe
The smooth performance in road, to reduce the performance of balanced device；The third, the 4th kind of situation can introduce ISI and ICI, systematicness can be made
Can occur significantly declining, therefore to avoid.
In the case of multipath channel, it is difficult to be located on ideal point, it is therefore desirable to determine a rational orientation range.
The deviations allowed are determined according to the smooth points of channel, it is assumed that the smooth points of selection are 11, when smooth first
Ensure that the phase of this continuous 11 point is continuous, i.e., the maximum phase difference of all frequency points is no more than π.The time then allowed
Deviation delta t is
In the case of 20MHz sample frequencys, the time interval in time domain between 2 points is 50ns, and Δ f is equal to
312.5kHz, therefore Δ t is equal to 150ns, ranging from advanced or lag desired position 3 points of point of actual location point, so not
Lubricity can be impacted.
In addition to this, multi-input multi-output system (Multiple-Input Multiple-Output, abbreviation MIMO)
In the case of, per strip antenna, there are fixed delays, not only need to consider multipath when synchronous, it is also necessary to consider that the fixation of antenna is prolonged
When.
Therefore, how a kind of synchronized algorithm suitable for multi-input multi-output system is provided, positioning accuracy is not being influenced
Under the premise of reduce the complexity of calculating, be problem to be solved.
Invention content
Technical problem to be solved by the invention is to provide a kind of signal synchronizing method and devices, can be how defeated in multi input
Go out in system the positioning accuracy for ensureing to receive when signal synchronizes, and reduces the complexity of calculating.
The embodiment of the present invention provides a kind of signal synchronizing method, including：
It is locked in automatic growth control AGC unit and receives signal that signal Shi Duige roads reception antenna receives into line delay
Auto-correlation processing receives signal reference corresponding with road reception signal treated on road delay first time length Hou Jiangge
Thresholding is compared, and determines whether to complete thick synchronization according to each road comparison result；
After thick synchronously complete, signal is received to each road and carries out local cross correlation process, by each road cross correlation process
Result be weighted cumulative and filtering, search for maximum value from filtered signal, judge to complete when searching maximum value
Essence is synchronous.
The embodiment of the present invention provides a kind of signal synchronizing device, including：
Thick synchronization module receives the reception antenna reception of the roads signal Shi Duige for being locked in automatic growth control AGC unit
The signal arrived receives signal and is connect with the road into line delay auto-correlation processing, treated on delay first time length Hou Jiangge road
Number corresponding thresholding that refers to of collecting mail is compared, and determines whether to complete thick synchronization according to each road comparison result；
Smart synchronization module, for after thick synchronously complete, receiving signal to each road and carrying out local cross correlation process, Jiang Gelu
The result of local cross correlation process is weighted cumulative and filtering, searches for maximum value from filtered signal, is searching most
It is synchronous to complete essence for judgement when big value.
Compared with prior art, a kind of signal synchronizing method of offer of the embodiment of the present invention and device, in automatic growth control
The signal that the roads AGC unit locking reception signal Shi Duige reception antenna receives is into line delay auto-correlation processing, in delay first
Treated on the roads time span Hou Jiangge receives signal and the road and receives the corresponding reference thresholding of signal and be compared, according to each road
Comparison result determines whether to complete thick synchronization；After thick synchronously complete, signal is received to each road and carries out local cross correlation process, it will
The result of each road cross correlation process is weighted cumulative and filtering, searches for maximum value from filtered signal, is searching for
It is synchronous that essence is completed to judgement when maximum value.The embodiment of the present invention can ensure that receiving signal synchronizes in multi-input multi-output system
When positioning accuracy, and reduce the complexity of calculating.
Description of the drawings
Fig. 1 is the schematic diagram that digital receiver receives signal and demodulated in the prior art；
Fig. 2 is the anchor point schematic diagram that symbol location synchronizes in the prior art；
Fig. 3 is a kind of flow chart of signal synchronizing method of the embodiment of the present invention 1；
Fig. 4 is a kind of block diagram representation of thick synchronization process in the embodiment of the present invention 1；
Fig. 5 is the time diagram that Time-delayed trigger slightly synchronizes detection in the embodiment of the present invention 1；
Fig. 6 is a kind of block diagram representation of smart synchronization process in the embodiment of the present invention 1；
Fig. 7 is slightly to synchronize detects schematic diagram using AGC locking times Time-delayed trigger in example 1 of the present invention；
Fig. 8 is in example 2 of the present invention with reference to the schematic diagram of threshold generation and thick synchronous detection triggering；
Fig. 9 is a kind of schematic diagram of signal synchronizing device of the embodiment of the present invention 2.
Specific implementation mode
To make the objectives, technical solutions, and advantages of the present invention clearer, below in conjunction with attached drawing to the present invention
Embodiment be described in detail.It should be noted that in the absence of conflict, in the embodiment and embodiment in the application
Feature mutually can arbitrarily combine.
Embodiment 1
As shown in figure 3, an embodiment of the present invention provides a kind of signal synchronizing methods, including：
Step S310 locks the letter for receiving the roads signal Shi Duige reception antenna and receiving in automatic growth control AGC unit
Number into line delay auto-correlation processing, receives signal and receive signal with the road treated on delay first time length Hou Jiangge road
It is corresponding to be compared with reference to thresholding, determine whether to complete thick synchronization according to each road comparison result；
Step S320 receives signal to each road and carries out local cross correlation process after thick synchronously complete, and each road is mutual
The result of relevant treatment is weighted cumulative and filtering, maximum value is searched for from filtered signal, when searching maximum value
It is synchronous that essence is completed in judgement.
In one embodiment, it is described to signal that arbitrarily reception antenna receives all the way at line delay auto-correlation
Reason, including：
Collection of letters r (n) symbol auto-correlation computation for being clapped into line delay N is docked according to period N of short training sequence, obtains the
One signal Λ (m)；
Wherein, the symbol auto-correlation computation that the delay N is clapped can be indicated by following formula (2-1)：
Wherein, N is the period of the short training sequence (Shorting Training Field, abbreviation STF), if adopted
Sample frequency is 20MHz, then N is equal to 16；R (n) is to receive signal, r*(n) it is the conjugation for receiving signal；Sign () is to take symbol letter
Number；
Wherein, the short training sequence for signal detection, AGC power regulations, slightly synchronize, STF belong to sending side with
And a kind of sequence known to receiving side, can judge to receive by this sequence is any signal, and can be subsequent fine
Synchronization process provides certain reference and buffering.
In one embodiment, the first time length is that the duration T 1 of short training sequence subtracts AGC unit
Locking receives the maximum time T2 of signalmaxTime span afterwards；
Wherein, under normal circumstances, AGC unit locking receives the time t2 of signal no more than T2max；
In one embodiment, it is that signal is received at one according to the road per the corresponding thresholding that refers to of signal is received all the way
Delay autocorrelation result in the short training sequence period be averaged after multiplied by being obtained with 0.5.
In one embodiment, by treated on each road receive signal and the road receive signal it is corresponding refer to thresholding into
Row compares, and is determined whether to complete thick synchronization according to each road comparison result, including：
If treated all the way, reception signal reaches the road and receives the corresponding reference thresholding of signal and continue for some time
Reach with reference to thresholding, then judges that the road receives signal and meets thick synchronous requirement；
At least exist receive all the way signal meet slightly synchronize require when judgement complete it is thick synchronous.
Wherein, described to continue the retention time as preset value, such as 5 sampled points；
In one embodiment, described to carry out local cross correlation process to arbitrarily receiving signal all the way, including：
Collection of letters r (m) is docked according to period N of long training sequence and carries out local computing cross-correlation, obtains second signal Γ
(m)；
Wherein, the local computing cross-correlation can be indicated by following formula (2-2)：
Wherein, c (n) is the tap coefficient of filter, and the tap coefficient of filter is carried out according to the numerical value of long training sequence
Design；r*() is the conjugation for receiving signal；
In one embodiment, the result of each road cross correlation process is weighted cumulative and filtering, including：
The result of each road cross correlation process is subjected to the cumulative acquisition third signal of equal weight；
The third signal is sent into the filter that a tap number is a and is filtered；
Wherein, the product at the tap number a of the filter and reception signal sampling interval is greater than or equal between transmission antenna
Maximum delay；It is each to be more than other for the numerical value of tap coefficient corresponding with the first transmission antenna transmission signal in a tap coefficient
The numerical value of a tap coefficient；The advanced first transmission antenna hair of an any other transmission antenna in addition to the first transmission antenna
The number of delivering letters.
Wherein, maximum value is searched for from filtered signal, the position that maximum value occurs is exactly the position that LTF terminates,
It is the beginning of following symbol, due to having protection interval before each symbol, according between the positions terminated LTF and protection
Every length be assured that the initial position of each symbol, therefore, when searching maximum value judgement it is synchronous to complete essence.
In one embodiment, as shown in figure 4, thick synchronizing process may comprise steps of：
1) after AGC unit locks and receives signal, the first trigger signal is generated by trigger signal generator (401)；
2) signal received to each road reception antenna (402) according to first trigger signal is handled；
3) a docking collection of letters number point two-way is handled, wherein signal feeding takes symbolic unit to carry out taking symbolic operation all the way,
The symbol of taking-up is stored in the first first in, first out (First that a depth is N (N is the period of STF, for example, N=16)
Input First Output, abbreviation FIFO) in buffer (404), wherein another way signal feeding takes in conjugate unit (405)
It carries out taking conjugate operation；By the output signal of the first FIFO buffers and the output signal of conjugate unit is taken to carry out multiplication operation；
4) two-way will be divided by the signal of multiplication operation, wherein it is that (N is the week of STF to N that signal, which is stored in a depth, all the way
Phase, for example, N=16) the second first in, first out (First Input First Output, abbreviation FIFO) buffer (406) in,
Wherein another circuit-switched data and the output signal of the 2nd FIFO buffers carry out additive operation, and the signal after subtracting each other is sent into the modulus that adds up
Cumulative modulo operation is carried out in unit (407), thus completes the delay auto-correlation computation that a length of window is N (N=16)；
5) defeated after trigger signal generator (401) delay first time threshold T1 since AGC unit locks and receives signal
Go out the second trigger signal and give mean operation unit (408), the mean operation unit extracts the delay of certain length of window from phase
It closes result to be averaged to obtain reference thresholds, while triggering thick synchronous detection；
6) per the autocorrelation result that the corresponding comparing unit of reception antenna (409) exports cumulative modulus unit all the way and
The reference thresholding of value arithmetic element output is compared to obtain the comparison result of 1 bit；
7) by the 1 bit comparison result feeding of corresponding comparing unit (409) output of each road reception antenna or logical operation
Unit (410) generates the thick synchronized result of 1 bit；For example, when thick synchronized result is 1, judgement slightly synchronously completes；
Wherein, as shown in figure 5, for example, using AGC locking signals progress Time-delayed trigger, prolonging for certain length of window is extracted
When autocorrelation result be averaged to obtain threshold value, while triggering thick synchronous detection, the autocorrelative result that is delayed can successively with thresholding
Value is compared, and will not trigger thick synchronization when there is a point less than threshold value, continuous 5 times of the autocorrelative result that is only delayed
Thick synchronization can be just triggered less than threshold value.Because thick synchronous detection is not begun to from AGC lockings, but obtains referring to thresholding
Start, which reduce AGC to be locked to the thick synchronous detection that thresholding generates this period, can effectively reduce the hair of false synchronization
It is raw.
The above-mentioned purpose slightly synchronized is to synchronize calculating to trigger essence, and simultaneously provide a suitable calculation window for essence
Length.
In carrying out smart synchronizing process, using long training sequence (Long Training Field, abbreviation LTF) at one
Numerical values recited in period designs the digital filter that a tap number is 64, receives signal and passes through the filter, actually
Computing cross-correlation is done with the tap coefficient of filter, the computing cross-correlation can be indicated by following formula (2-2)：
Wherein, N indicates that the length of cross-correlation calculation, N are equal to 64；R (m) is to receive signal, and c (n) is the tap of filter
Coefficient；
Wherein, the period of the long training sequence LTF is 4 times of STF, same with the cycle phase of an OFDM, can be used for
Carry out synchronous essence, essence offset estimation, signal estimation.The embodiment of the present invention, with very strong correlation properties, is deposited using it locally
One section of processed LTF (i.e. the tap coefficient of filter) is stored up, shuts with local LTF phases when receiving signal and (peak value occurs), just
Think to synchronize.
Carry out essence it is synchronous during, for mimo system, due in addition to first antenna, when other antennas can pass through
Domain cyclic shift carries out look ahead (maximum is in advance 200ns, is 4 points for 20MHz sample frequencys), this leads to MIMO systems
System cannot be simply directly right like that as single-input single-output (single-input single-Output, abbreviation SISO) system
Cross-correlation peak value detection can be obtained by synchronized result.For MIMO, synchronous result must be the position that first peak value occurs
It sets.In order to relatively accurately navigate to ideal position, the embodiment of the present invention passes through one by the result of calculation to cross-correlation
The filter that a tap number is 6, then the maximum value of search filter output result, as final essence are same in a certain range
The result of step.
In addition, by attached drawing 1 it is found that sync bit is possible to the third situation occur namely timing estimation point is fallen next
In the cyclic prefix of a symbol, and best timing point is lagged behind, so positioning synchronous can be improved by being handled by locating bias
Dynamic range.For example, sync bit 6 points of forward movement are started to extract each OFDM symbol, before carrying out FFT, by this
The numerical value of the first six point of symbol is moved to the last position of symbol, can allow anchor point left in best orientation point in this way
Right swing.It not only ensure that positioning synchronous point can be moved left and right in best orientation point in this way, but also will not have been interfered between created symbol, carried
The high dynamic range of positioning synchronous.
In one embodiment, it is based on above-mentioned consideration, as shown in fig. 6, smart synchronizing process may include following step：
1) thick to synchronously complete trigger signal generator (601), the trigger signal generator generates third trigger signal (phase
When in the T2 times that are delayed after AGC locks the moment)；
2) signal that each road reception antenna receives corresponding each road first is sent into according to the third trigger signal to filter
Wave device is filtered in (602), is then re-fed into corresponding modulus unit (603) and is carried out modulus processing；
Wherein, the tap coefficient of filter is respective treated according to the progress of the time-domain signal of long training sequence, right first
The time-domain signal of long training sequence takes the symbol of determining filter tap coefficients after symbol, then according to the time domain of long training sequence
Filter coefficient is set as 0,1,2 by the size of signal amplitude, because the big noise resisting ability of amplitude is strong, confidence level is high, therefore gives
Give a larger weight.The plural number (for example, 1+2i) that the tap coefficient c (n) of filter in this way is formed by 0,1,2；
3) signal after each antenna modulus is sent into an accumulator (604) and carries out summation operation, be equivalent to each
Antenna computing cross-correlation result equal weight is superimposed；
4) signal that accumulator exports is input in a second filter (605) and is handled, the processing is used for
Reduce the influence of multiple antennas different delayed time and multipath；
Wherein, second filter is the equal of a sliding window summation, is weighted to one of value, sliding window can
The influence of antenna different delayed time and multipath is reduced, weighting can improve the peak strength of first transmission antenna, and it is fixed to be conducive to
The accuracy of positioning result is improved to the peak value of first antenna in position.
5) output signal of second filter is input in maximum value search unit (606) and carries out maximum value search, obtained
To smart synchronized result；
6) result that maximum value search unit exports is input in locating bias unit (607), forward by sync bit
Mobile 6 points start to extract each OFDM symbol, and before carrying out FFT, the numerical value of the first six point of the symbol is moved to symbol
Number last position obtains the initial position of extraction FFT windows after locating bias；In addition, the point of locating bias is extracting number
It is last that symbol is moved on to according to the rear cyclophysis using symbol；
The processing in thick synchronizing process and smart synchronizing process is further described below by some examples.
Example 1
As shown in fig. 7, after AGC lockings, receives signal and enter modem.It will not carry out slightly synchronous detection immediately at this time, but
The delay regular hour is just detected.The time (T) of delay is terminated by the short training sequence for slightly being synchronized
Time (702) subtracts what the time (701) that AGC is locked the latest obtained.
And in actual operation, after AGC locks (703), thresholding (704) is obtained by delay time (T), this makes thick synchronization
Detection (705) is happened at after thresholding generation.It will not be into after this makes AGC lock (703), before thick synchronous detection (705) triggering
The thick synchronous detection of row, this can effectively reduce the generation of false synchronization.
Example 2
As shown in figure 8, receive signal obtains output result (801) by delay auto-correlation processing, tied using this output
Fruit (801) calculates threshold value (802) locking Time-delayed trigger by AGC, output knot is extracted in the calculating of threshold value since triggering
It 16 values of fruit (801) and then is averaged to obtain, after the completion of threshold value calculates, threshold value comes into effect, and thick synchronous detection starts
It carries out, then exports result (801) and the comparison result of 1 bit is compared and exported by comparing device (803) with threshold value, than
Relatively result is all 15 tap filters (804), the value in the output data and register of filter by a tap coefficient
(805) it is compared, wherein the value in register is set as 5, and equal proof antenna, which slightly synchronizes, to be detected；5 tap
The effect of filter (804) is：It wants continuous 5 points to reach threshold value and is just considered slightly synchronous triggering；
The thick synchronous testing result of all antennas is handled by logical operation or (806), as long as there is a strip antenna
Thick synchronize is detected, and thick synchronizing process is just completed.
Thick synchronously complete will trigger the synchronous calculating of essence and detection.
Example 3
As shown in fig. 6, the tap coefficient of first filter (602) is designed according to the time-domain value of long training sequence, it is right respectively
The real part of long training sequence time-domain value is averaged respectively with imaginary part, and average value divided by 2 are obtained threshold value, when long training sequence
The real part of thresholding and imaginary part difference divided by its corresponding threshold value, then carry out round (absolute value to result of calculation
The tap coefficient c'(n for 2) obtaining final filter is taken more than 2).
In above-mentioned formula (3-1), c (n) is compressed to the time-domain signal of original LTF, that is, uses the bit table of very little
Show that the characteristic of the time-domain signal of LTF, X (n) are LTF time-domain signals, N=64 represents the period of LTF, and round () is rounding letter
Number；
In above-mentioned formula (3-2), c'(n) it is tap coefficient (long training sequence being locally stored)；
For second filter (605), second filter one shares 6 taps, and tap coefficient is：{ 1,1,1,1,2,1 },
The delay between multipath effect and different antennae can be resisted using second filter, while day is received using improving first
The weighted value of line peak value makes synchronized result be located on first reception antenna.
As shown in figure 9, an embodiment of the present invention provides a kind of signal synchronizing devices, including：
Thick synchronization module 901 connects for locking the roads reception signal Shi Duige reception antenna in automatic growth control AGC unit
The signal received receives signal and the road into line delay auto-correlation processing, treated on delay first time length Hou Jiangge road
It receives the corresponding thresholding that refers to of signal to be compared, determines whether to complete thick synchronization according to each road comparison result；
Smart synchronization module 902 will for after thick synchronously complete, receiving signal to each road and carrying out local cross correlation process
The result of each road cross correlation process is weighted cumulative and filtering, searches for maximum value from filtered signal, is searching for
It is synchronous that essence is completed to judgement when maximum value.
In one embodiment, thick synchronization module, in the following ways to arbitrarily reception antenna receives all the way
Signal into line delay auto-correlation processing：
Collection of letters r (n) symbol auto-correlation computation for being clapped into line delay N is docked according to period N of short training sequence, obtains the
One signal Λ (m)；
Wherein, the symbol auto-correlation computation that the delay N is clapped can be indicated by following formula：
Wherein, N is the period of the short training sequence STF, and r (n) is to receive signal, r*(n) it is the conjugation for receiving signal；
Sign () is to take sign function.
In one embodiment, the first time length is that the duration T 1 of short training sequence subtracts AGC unit
Locking receives the maximum time T2 of signalmaxTime span afterwards.
In one embodiment, it is that signal is received at one according to the road per the corresponding thresholding that refers to of signal is received all the way
Delay autocorrelation result in the short training sequence period be averaged after multiplied by being obtained with 0.5.
In one embodiment, thick synchronization module, in the following ways by treated on each road receive signal with
The road receives the corresponding thresholding that refers to of signal and is compared, and determines whether to complete thick synchronization according to each road comparison result：
If treated all the way, reception signal reaches the road and receives the corresponding reference thresholding of signal and continue for some time
Reach with reference to thresholding, then judges that the road receives signal and meets thick synchronous requirement；
At least exist receive all the way signal meet slightly synchronize require when judgement complete it is thick synchronous.
In one embodiment, smart synchronization module, for carrying out this to arbitrarily receiving signal all the way in the following ways
Ground cross correlation process：
Collection of letters r (m) is docked according to period N of long training sequence and carries out local computing cross-correlation, obtains second signal Γ
(m)；
Wherein, the local computing cross-correlation can be indicated by following formula：
Wherein, c (n) is the tap coefficient of filter, and the tap coefficient of filter is carried out according to the numerical value of long training sequence
Design；r*() is the conjugation for receiving signal.
In one embodiment, smart synchronization module, in the following ways by the knot of each road cross correlation process
Fruit is weighted cumulative and filtering：
The result of each road cross correlation process is subjected to the cumulative acquisition third signal of equal weight；
The third signal is sent into the filter that a tap number is a and is filtered；
Wherein, the product at the tap number a of the filter and reception signal sampling interval is greater than or equal between transmission antenna
Maximum delay；It is each to be more than other for the numerical value of tap coefficient corresponding with the first transmission antenna transmission signal in a tap coefficient
The numerical value of a tap coefficient；The advanced first transmission antenna hair of an any other transmission antenna in addition to the first transmission antenna
The number of delivering letters.
It should be noted that the invention may also have other embodiments, without departing substantially from spirit of that invention and its essence
In the case of, those skilled in the art can make various corresponding change and deformations according to the present invention, but these are corresponding
Change and distortion should all belong to the protection domain of appended claims of the invention.
Claims (14)
1. a kind of signal synchronizing method, including：
It is locked in automatic growth control AGC unit and receives signal that signal Shi Duige roads reception antenna receives into line delay from phase
Pass is handled, and receives signal with the road to receive signal corresponding with reference to thresholding treated on road delay first time length Hou Jiangge
It is compared, determines whether to complete thick synchronization according to each road comparison result；
After thick synchronously complete, signal is received to each road and carries out local cross correlation process, by the knot of each road cross correlation process
Fruit is weighted cumulative and filtering, and maximum value is searched for from filtered signal, and when searching maximum value, judgement completion essence is same
Step.
2. the method as described in claim 1, it is characterised in that：
It is described to signal that arbitrarily reception antenna receives all the way into line delay auto-correlation processing, including：
The symbol auto-correlation computation that collection of letters r (n) is clapped into line delay N is docked according to period N of short training sequence, obtains the first letter
Number Λ (m)；
Wherein, the symbol auto-correlation computation that the delay N is clapped can be indicated by following formula：
Wherein, N is the period of the short training sequence STF, and r (n) is to receive signal, r*(n) it is the conjugation for receiving signal；sign
() is to take sign function.
3. method as claimed in claim 1 or 2, it is characterised in that：
The first time length is that the duration T 1 of short training sequence subtracts the maximum time that AGC unit locking receives signal
T2maxTime span afterwards.
4. method as claimed in claim 2, it is characterised in that：
Per all the way receive signal it is corresponding with reference to thresholding be according to the road receive signal prolonging within a short training sequence period
When autocorrelation result be averaged after multiplied by obtaining with 0.5.
5. the method as described in claim 1, it is characterised in that：
It receives treated on each road signal and the road and receives the corresponding reference thresholding of signal and be compared, knot is compared according to each road
Fruit determines whether to complete thick synchronization, including：
If treated all the way, reception signal reaches the corresponding reference thresholding of road reception signal and continues for some time and reaches
It is required to reference to thresholding, then judging that road reception signal meets slightly to synchronize；
At least exist receive all the way signal meet slightly synchronize require when judgement complete it is thick synchronous.
6. the method as described in claim 1, it is characterised in that：
It is described to carry out local cross correlation process to arbitrarily receiving signal all the way, including：
Collection of letters r (m) is docked according to period N of long training sequence and carries out local computing cross-correlation, obtains second signal Γ (m)；
Wherein, the local computing cross-correlation can be indicated by following formula：
Wherein, c (n) is the tap coefficient of filter, and the tap coefficient of filter is designed according to the numerical value of long training sequence；
r*() is the conjugation for receiving signal.
7. the method as described in claim 1, it is characterised in that：
The result of each road cross correlation process is weighted cumulative and filtering, including：
The result of each road cross correlation process is subjected to the cumulative acquisition third signal of equal weight；
The third signal is sent into the filter that a tap number is a and is filtered；
Wherein, the product at the tap number a of the filter and reception signal sampling interval is greater than or equal between transmission antenna most
Big delay；The numerical value of tap coefficient corresponding with the first transmission antenna transmission signal is more than other each pumpings in a tap coefficient
The numerical value of head coefficient；Advanced first transmission antenna of an any other transmission antenna in addition to the first transmission antenna sends letter
Number.
8. a kind of signal synchronizing device, including：
Thick synchronization module receives what the roads signal Shi Duige reception antenna received for being locked in automatic growth control AGC unit
Signal receives signal and is received with the road and believe into line delay auto-correlation processing, treated on delay first time length Hou Jiangge road
It is number corresponding to be compared with reference to thresholding, determine whether to complete thick synchronization according to each road comparison result；
Smart synchronization module, for after thick synchronously complete, receiving signal to each road and carrying out local cross correlation process, by each road
The result of cross correlation process is weighted cumulative and filtering, searches for maximum value from filtered signal, is searching maximum value
When judgement to complete essence synchronous.
9. device as claimed in claim 8, it is characterised in that：
Thick synchronization module, in the following ways to signal that arbitrarily reception antenna receives all the way at line delay auto-correlation
Reason：
The symbol auto-correlation computation that collection of letters r (n) is clapped into line delay N is docked according to period N of short training sequence, obtains the first letter
Number Λ (m)；
Wherein, the symbol auto-correlation computation that the delay N is clapped can be indicated by following formula：
Wherein, N is the period of the short training sequence STF, and r (n) is to receive signal, r*(n) it is the conjugation for receiving signal；sign
() is to take sign function.
10. device as claimed in claim 8 or 9, it is characterised in that：
The first time length is that the duration T 1 of short training sequence subtracts the maximum time that AGC unit locking receives signal
T2maxTime span afterwards.
11. device as claimed in claim 9, it is characterised in that：
Per all the way receive signal it is corresponding with reference to thresholding be according to the road receive signal prolonging within a short training sequence period
When autocorrelation result be averaged after multiplied by obtaining with 0.5.
12. device as claimed in claim 8, it is characterised in that：
Thick synchronization module, for receiving signal reference corresponding with road reception signal by treated on each road in the following ways
Thresholding is compared, and determines whether to complete thick synchronization according to each road comparison result：
If treated all the way, reception signal reaches the corresponding reference thresholding of road reception signal and continues for some time and reaches
It is required to reference to thresholding, then judging that road reception signal meets slightly to synchronize；
At least exist receive all the way signal meet slightly synchronize require when judgement complete it is thick synchronous.
13. device as claimed in claim 8, it is characterised in that：
Smart synchronization module, for carrying out local cross correlation process to arbitrarily receiving signal all the way in the following ways：
Collection of letters r (m) is docked according to period N of long training sequence and carries out local computing cross-correlation, obtains second signal Γ (m)；
Wherein, the local computing cross-correlation can be indicated by following formula：
Wherein, c (n) is the tap coefficient of filter, and the tap coefficient of filter is designed according to the numerical value of long training sequence；
r*() is the conjugation for receiving signal.
14. device as claimed in claim 8, it is characterised in that：
Smart synchronization module, for the result of each road cross correlation process to be weighted cumulative and filtering in the following ways：
The result of each road cross correlation process is subjected to the cumulative acquisition third signal of equal weight；
The third signal is sent into the filter that a tap number is a and is filtered；
Wherein, the product at the tap number a of the filter and reception signal sampling interval is greater than or equal between transmission antenna most
Big delay；The numerical value of tap coefficient corresponding with the first transmission antenna transmission signal is more than other each pumpings in a tap coefficient
The numerical value of head coefficient；Advanced first transmission antenna of an any other transmission antenna in addition to the first transmission antenna sends letter
Number.
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| CN110224964A (en) * | 2019-06-12 | 2019-09-10 | 珠海市杰理科技股份有限公司 | Symbol timing synchronization method, device, receiver device and storage medium |
| CN113890802A (en) * | 2021-09-01 | 2022-01-04 | 杭州电子科技大学富阳电子信息研究院有限公司 | Symbol timing synchronization method based on PN sequence |
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| WO2018188659A1 (en) | 2018-10-18 |
| CN108736931B (en) | 2020-11-10 |
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