CN107370705A - FFT optimization method in the capture of high dynamic weakly continuous phase modulated signal - Google Patents

FFT optimization method in the capture of high dynamic weakly continuous phase modulated signal Download PDF

Info

Publication number
CN107370705A
CN107370705A CN201710494935.3A CN201710494935A CN107370705A CN 107370705 A CN107370705 A CN 107370705A CN 201710494935 A CN201710494935 A CN 201710494935A CN 107370705 A CN107370705 A CN 107370705A
Authority
CN
China
Prior art keywords
signal
data
fft
correlation function
frequency
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
Application number
CN201710494935.3A
Other languages
Chinese (zh)
Other versions
CN107370705B (en
Inventor
孙锦华
岳家弘
王昊
吕珊珊
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xidian University
Original Assignee
Xidian University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Xidian University filed Critical Xidian University
Priority to CN201710494935.3A priority Critical patent/CN107370705B/en
Publication of CN107370705A publication Critical patent/CN107370705A/en
Application granted granted Critical
Publication of CN107370705B publication Critical patent/CN107370705B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • H04L27/2689—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation
    • H04L27/2695—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation with channel estimation, e.g. determination of delay spread, derivative or peak tracking
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0014—Carrier regulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2657—Carrier synchronisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • 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
    • H04L27/2668—Details of algorithms
    • H04L27/2669—Details of algorithms characterised by the domain of operation
    • H04L27/2672—Frequency domain
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/38—Demodulator circuits; Receiver circuits
    • H04L27/3845—Demodulator circuits; Receiver circuits using non - coherent demodulation, i.e. not using a phase synchronous carrier
    • H04L27/3854—Demodulator circuits; Receiver circuits using non - coherent demodulation, i.e. not using a phase synchronous carrier using a non - coherent carrier, including systems with baseband correction for phase or frequency offset
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0014—Carrier regulation
    • H04L2027/0024—Carrier regulation at the receiver end
    • H04L2027/0026—Correction of carrier offset

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

FFT optimization method, mainly solves the problems, such as that prior art capture time and sample frequency are too high in being captured the invention discloses a kind of high dynamic weakly continuous phase modulated signal.Its implementation is：First the signal received is filtered successively in receiving terminal, down coversion and digital sample, obtains baseband complex signal and frequency difference compensation is carried out to it；FFT computings are carried out to signal after compensation and local CA codes modulated signal respectively again, and leave preceding 1/4 data after calculating, remaining 3/4 data are arranged to zero, obtain two groups of sample sequences；Then by two groups of sample sequence conjugate multiplications, result progress IFFT computings are obtained into correlation function；Last pair correlation function carry out accumulation and square, obtain judgement amount, if obvious peak value occurs in judgement amount, judge acquisition success, otherwise unsuccessful.The present invention improves capture time, reduces complexity, available in CPM signal acquisition systems and satellite communication without using too high sample frequency.

Description

FFT optimization method in the capture of high dynamic weakly continuous phase modulated signal
Technical field
The invention belongs to space communications technique field, more particularly to a kind of Fast Fourier Transform (FFT) in signal capture FFT points optimization methods, available for high dynamic weakly continuous phase-modulation CPM signal acquisition systems and satellite based on correlation function The communications field.
Background technology
The weak CPM signal captures of high dynamic are the premises that system is normally carried out follow-up work, and it is widely used in satellite communication, Especially field of deep space communication, but power and bandwidth can be very limited.Spread spectrum because its strong antijamming capability, can The features such as being communicated under Arctic ice area, it is the most frequently used technology in the above-mentioned communications field.Weigh the capture of spread-spectrum signal Can index be mainly the complexity of system, capture time and be captured as power, these problems are the key points for needing to pay close attention to.
In research at home and abroad, the capture of the CPM weak signals by spread processing is primarily directed to pseudo-code phase and load The synchronization of ripple Doppler frequency, traditional technology mainly have：Independent channel method, sliding correlation detector method, matched filter method etc., this Although a little methods realize that simply for the complexity of system than relatively low, most capture time is very long, it is impossible to meets actual Demand.In late 1980s, with the development of FFT technique and DSP technologies, the acquisition algorithm based on FFT is increasingly becoming this Area research focus.Related operation in time domain is changed into the conjugation of frequency domain using FFT property by FFT and IFFT computings Multiplication operation so that the operation times of whole acquisition procedure greatly reduce, and this method is used for GPS receiver.It is same with this When, some scholars it is also proposed the optimized algorithm of correlation.
Vandana Patel are in " Reduced-Size FFT Correlation Techniques For GPS One is proposed in Signal Acquisition ", Evolution in Networks and Computer Communications Kind reduces the optimized algorithm for participating in related operation FFT points, and Capturing Models of the algorithm according to the correlation function of spread-spectrum signal are logical Crossing reduces FFT and IFFT sample frequency, to reduce the points that each code element cycle in signal participates in computing, can thus drop Low capture time, improve capture rate.As shown in Figure 1, its specific implementation step is as follows for basic Capturing Models：The first step, It is local to preset an initial hypothesis Doppler-frequency estimation value using complex carrier signal generatorIt is by frequencyComplex carrier signal Signal is multiplied with reception signal, then carries out N point FFT computings, wherein, N is the sampling of the CPM modulated signals in a spreading code cycle Points；Second step, CPM modulation is carried out to local spreading code, then carry out N points FFT calculating, its complex conjugate is asked to all points；The Three steps, the result obtained to first two steps are multiplied, and carry out N points IFFT calculating, one group of cross-correlation function value are obtained, if obtained bright Aobvious peak value, then it represents that acquisition success, the Doppler-frequency estimation value now assumedAnd code phase, if do not obtained bright Aobvious peak value, then separately set new hypothesis Doppler-frequency estimation valueAnd repeat said process.
In this optimized algorithm, the sample frequency for carrying out FFT and IFFT is 20MHz, and spreading rate is 1.024MHz, is being expanded In frequency code a cycle 1ms time, there are 20000 sampled points, if sample frequency is reduced as 1/4 originally, in an expansion In the frequency code cycle, sampling number is reduced to 5000, can thus reduce by 3/4 amount of calculation.But in actual applications, adopt Sample frequency can't be arranged to nearly 20 times of spreading rate, also, it reduces the way of sample frequency, even if sample frequency reduces To original 1/8, also meet the requirement of Nyquist criterion, therefore requirement of such way to system hardware is very high, and Cause a large amount of wastes for calculating data.
The content of the invention
It is an object of the invention to for above-mentioned the deficiencies in the prior art, there is provided a kind of high dynamic weakly continuous phase-modulation letter FFT optimization method in number capture, with relatively low sample frequency and system complexity, obtain higher acquisition probability and less catch Obtain the time.
Realize the technical scheme is that, for each hypothesis Doppler-frequency estimation value, respectively to local expansion Frequency code and receiving terminal process signal carry out FFT calculating, then intercept the point that main information is included in result of calculation, and by left point Zero is dimensioned to, according to the good autocorrelation performance of spreading code, one-time calculation goes out corresponding to all local spread spectrum code phases Cross correlation value, then accumulated and taken the processing of envelope, terminal decision whether acquisition success.Implementation step includes as follows：
(1) in transmitting terminal, a segment information sequence is passed through into CA code spread spectrum operations, one group of frequency expansion sequence is formed, to the sequence Offset quadrature phase-shift-keying SOQPSK modulation and up-conversion, the radiofrequency signal sent are formed successively；
(2) in receiving terminal, the radiofrequency signal received is filtered successively, down coversion and digital sample, obtains base band Complex signal rn；
(3) to baseband complex signal rnCarry out frequency difference compensation：
The Doppler-frequency estimation value of (3a) calculation assumptionAnd complex carrier signal generator is utilized, obtain complex carrier signal signalWherein tnIt is n-th of sampling instant；
(3b) utilizes complex carrier signal signalTo baseband complex signal rnCompensate, be compensated rear signal
(4) to signal after compensationCarry out N points FFT to calculate, leave preceding 1/4 data being calculated, and by more than Under 3/4 data be arranged to zero, obtain frequency domain sample sequence [Y0,Y1...Yi...YN-1], i=0,1,2...N-1, wherein N It is signal after compensatingCarry out the points of FFT calculating；IfThen YiIt is signal after compensatingBy N points I-th of data that FFT is calculated, ifThen YiIt is 0；
(5) the CA codes used in (1) are subjected to SOQPSK modulation, carrying out N points FFT to the data after modulation calculates, and leaves Preceding 1/4 data being calculated, and remaining 3/4 data are arranged to zero, then the complex conjugate of all data is calculated, obtain To frequency domain sample sequenceIfThenIt is that data pass through N after modulating The complex conjugate for h-th of data that point FFT is calculated, ifThenIt is 0；
(6) by [Y0,Y1...Yi...YN-1] withIt is multiplied, then N points IFFT is carried out to multiplied result Calculate, obtain all code phasesCorresponding correlation function
(7) to the correlation function in adjacent spreading code cycleAdded up, the correlation function after being handled
(8) pair correlation functionSquare operation is carried out, obtains decision valueConfirm further according to the decision value Whether acquisition success：IfIn the presence of obvious peak value, then it is assumed that acquisition success, it is on the contrary, then it is assumed that capture failure.
The present invention has advantages below compared with prior art：
First, the present invention does not need to use too high sample frequency, it is only necessary to meet nyquist sampling criterion, The complexity of system is reduced, is more easily implemented on hardware.
Second, the present invention intercepts to the FFT result of calculations of reception signal and local spreading code first, then again will be by The point given up is arranged to zero, so does the autocorrelation performance for being capable of basic guarantee sequence, can also save and calculate the time.
Brief description of the drawings
Fig. 1 is the existing correlation function catching method schematic diagram based on FFT
Fig. 2 is the high dynamic CPM weak signal capture systems schematic diagrames that the present invention uses；
Fig. 3 realizes schematic diagram for the present invention's；
Fig. 4 is with the existing correlation function catching method judgement capture whether successful analogous diagram of signal based on FFT；
Fig. 5 is to capture the whether successful analogous diagram of signal with present invention judgement.
Embodiment
The embodiment of the present invention and effect are further described below in conjunction with the accompanying drawings：
Reference picture 2, the weak CPM signal acquisition systems of the high dynamic based on correlation function of the present embodiment application, including send End and receiving terminal, channel model use the Gaussian white noise channel of additional carrier frequency deviation and skew.Its basic functional principle is as follows：
Transmitting terminal, one segment information sequence is subjected to Direct-Spread operation using spreading code, it is formed afterwards skew QPSK SOQPSK is modulated, the baseband complex signal sent, then the radiofrequency signal sent after up-conversion；
Receiving terminal, the radiofrequency signal received is filtered successively, base band letter in reply is obtained after down coversion and digital sample Number rn.By based on the acquisition procedure of fft algorithm to baseband complex signal rnCorrelation function calculating is carried out, obtains that there is sentencing for peak value Certainly measure, Doppler frequency and code phase corresponding to the decision value, as need the frequency deviation and code-phase compensated to reception signal Position.
Involved in the present invention be improved for the data of FFT computings, i.e., by calculating participating in correlation function The optimization of data, realize and the peak value of judgement amount obtained with relatively low sample frequency and relatively low system complexity, obtain carrier wave frequency deviation and Code phase.
Step bag is realized in reference picture 3, the progress FFT optimizations of the invention in the capture of high dynamic weakly continuous phase modulated signal Include as follows：
Step 1, in transmitting terminal, a segment information sequence is passed through into CA code spread spectrum operations, one group of frequency expansion sequence is formed, to the sequence Offset quadrature phase-shift-keying SOQPSK modulation and up-conversion, the radiofrequency signal sent is formed in row.
The code length of the CA codes used in the embodiment of the present invention is 1024, and spreading rate is 1.024MHz, and information sequence grows 200 Bit.SOQPSK modulation is carried out again after being spread to information sequence, the baseband complex signal sent：
S (t)=sI(t)+jsQ(t), wherein sIAnd s (t)Q(t) it is respectively in-phase component signal and orthogonal component signal；
The baseband complex signal s (t) of transmission is passed through into up-conversion, the radiofrequency signal sent again.
Step 2, in receiving terminal, the radiofrequency signal received is filtered successively, obtained after down coversion and digital sample Baseband complex signal rn, it is expressed as：
rn=s (tn-ts)·exp[j2π·fd·tn]+xn,
Wherein, rnIt is in the case of discrete time, to reception signal in tnThe sampled value at moment, s (tn-ts) it is CA codes warp Cross the complex baseband signal that SOQPSK modulates to obtain, tsIt is baseband complex signal s (tn-ts) initial time, and the one of its code phase Individual measurement, fdIt is Doppler frequency, tn=nTs, wherein Ts=1/fsOr Ts=tn-tn-1For sampling interval, fsIt is the sampling of signal Speed, xnIt is the multiple Gauss stochastic variable of zero-mean, variance δ2=N0/ 2, N0For noise one-sided power spectrum density.
Sampling rate f is taken in the present embodiments=4.096MHz, carrier wave frequency deviation fd=18KHz, code phase are that 128 chips are wide Degree.
Step 3, to baseband complex signal rnCarry out frequency difference compensation.
The Doppler-frequency estimation value of hypothesis is calculated as follows in (3a)
Wherein L=(fd max-fd min)/δf+ 1, δf=2/5TCOH, TCOHIt is the coherent accumulation cycle, fd min=-120KHz is The minimum value of Doppler-frequency estimation value, fd max=120KHz is the maximum of Doppler-frequency estimation value.
(3b) is according to the Doppler-frequency estimation value of hypothesisComplex carrier signal signal is obtained using complex carrier signal generator：
Wherein tnIt is n-th of sampling instant, j is imaginary unit；
(3c) utilizes complex carrier signal signalTo baseband complex signal rnCompensate, be compensated rear signal：
Wherein n=0,1,2 ..., N-1.
Step 4, the frequency domain sample sequence of reception signal is obtained according to signal after compensation.
To signal after compensationCarry out N points FFT to calculate, leave preceding 1/4 data being calculated, and by remainder 3/4 data be arranged to zero, obtain the frequency domain sample sequence [Y of reception signal0,Y1...Yi...YN-1], i=0,1,2...N- 1, wherein N are signals after compensationCarry out the points of FFT calculating, YiBe reception signal frequency domain sample sequence in i-th Data, changed according to i value, it may be determined that YiTake different numerical value：
IfThen YiIt is signal after compensatingI-th of the data calculated by N points FFT；
IfThen YiSize be 0.
Step 5, local frequency domain sample sequence is obtained according to local CA codes.
The CA codes used in step 1 are carried out SOQPSK modulation by (5a), are carried out N point FFT computings to the data after modulation, are obtained To local frequency domain sample sequence [S0,S1...Sm...SN-1], m=0,1,2 ... N-1, wherein SmIt is that signal passes through N points after modulating The than the m-th data that FFT is calculated,
The mathematical notation of the step is：
Wherein [s0,s1...sN-1] it is CA codes after SOQPSK is modulated；
(5b) leaves local frequency domain sample sequence [S0,S1...SN-1] preceding 1/4 data, and by remaining 3/4 data Zero is arranged to, then calculates the complex conjugate of all data, obtains local frequency domain sample sequenceIt is H-th of data in local frequency domain sample sequence, h=0,1,2...N-1, changed according to h value, it may be determined thatTake different numbers Value：
IfThenIt is complex conjugate of the data by N points FFT h-th of the data calculated after modulating；
IfThenIt is 0.
The mathematical notation of the step is：
Wherein, conj represents to take complex conjugate.
Step 6, correlation function is obtained according to the frequency domain sample sequence of reception signal and local frequency domain sample sequence.
By the frequency domain sample sequence [Y of reception signal0,Y1...Yi...YN-1] and local frequency domain sample sequenceIt is multiplied, then N points IFFT is carried out to multiplied result and calculated, obtains all code phasesCorresponding correlation Function
Step 7, pair correlation function is accumulated.
(7a) sets the correlation function in r-th of spreading code cycleFor：
WhereinIt is signalReduced form, represent complex conjugate of the local CA codes after SOQPSK is modulated, K=0,1,2...N-1,1≤r≤NCOH, NCOH=1,2,3... is the number for carrying out the cumulative accumulation cycle；
(7b) is by NCOHThe correlation function in individual cycleAdded up, obtained correlation function is：
Step 8, decision value is obtained according to the correlation function after accumulation.
In order to remove the influence of carrier wave skew, pair correlation functionSquare operation is carried out, obtains decision value
The effect of the present invention can be further illustrated by following emulation：
1. simulation system parameters are set
The emulation of the present invention uses the simulation softwares of Matlab 7.6, and simulation parameter is set and parameter one used in embodiment Cause, i.e., channel model is using the Gaussian white noise channel of additional carrier frequency deviation and skew, information sequence 200 bits of length, Doppler Frequency search range：[- 120KHz~120KHz], spreading rate 1.024Mchip/s, carrier doppler skew 18KHz.
2. emulation content
Emulation 1, if the code phase t of channel-attachsFor 128 chip width, after data have been carried out with FFT operations, The size that all 4096 point datas calculate the cross-correlation function under different frequency deviations and code phase is chosen, as a result as shown in Figure 4.
From fig. 4, it can be seen that being 128 chip width in code phase and frequency deviation is that 18KHz point obvious peak occurs Value, illustrates acquisition success.
Emulation 2, set the code phase t of channel-attachsFor 128 chip width, it is operated having carried out FFT to data Afterwards, first 1024 points of all 4096 point datas are left, and remaining 3072 point datas are arranged to 0, other operations and emulation 1 one Cause, obtain size of the cross-correlation function under different frequency deviations and code phase, as a result as shown in Figure 5.
From fig. 5, it can be seen that being 128 chip width in code phase and frequency deviation is that 18KHz point obvious peak occurs Value, illustrates acquisition success.

Claims (3)

1. FFT optimization method in a kind of high dynamic weakly continuous phase modulated signal capture, including：
(1) in transmitting terminal, a segment information sequence is passed through into CA code spread spectrum operations, forms one group of frequency expansion sequence, to the sequence successively Offset quadrature phase-shift-keying SOQPSK modulation and up-conversion, the radiofrequency signal sent is formed；
(2) in receiving terminal, the radiofrequency signal received is filtered successively, down coversion and digital sample, obtains base band letter in reply Number rn；
(3) to baseband complex signal rnCarry out frequency difference compensation：
The Doppler-frequency estimation value of (3a) calculation assumptionAnd complex carrier signal generator is utilized, obtain complex carrier signal signal Wherein tnIt is n-th of sampling instant；
(3b) utilizes complex carrier signal signalTo baseband complex signal rnCompensate, be compensated rear signal
(4) to signal after compensationCarry out N points FFT to calculate, leave preceding 1/4 data being calculated, and will be remaining 3/4 data is arranged to zero, obtains frequency domain sample sequence [Y0,Y1...Yi...YN-1], i=0,1,2...N-1, wherein N is to mend Repay rear signalCarry out the points of FFT calculating；IfThen YiIt is signal after compensatingCounted by N points FFT I-th of the data calculated, ifThen YiIt is 0；
(5) the CA codes used in (1) are subjected to SOQPSK modulation, carrying out N points FFT to the data after modulation calculates, and leaves calculating Obtained preceding 1/4 data, and remaining 3/4 data are arranged to zero, then the complex conjugate of all data is calculated, obtain frequency Domain sample sequenceIfThenIt is that data pass through N points FFT after modulating The complex conjugate of h-th of the data calculated, ifThenIt is 0；
(6) by [Y0,Y1...Yi...YN-1] withIt is multiplied, then N points IFFT is carried out to multiplied result and calculated, Obtain all code phasesCorresponding correlation function
(7) to the correlation function in adjacent spreading code cycleAdded up, the correlation function after being handled
(8) pair correlation functionSquare operation is carried out, obtains decision valueIt is confirmed whether further according to the decision value Acquisition success：IfIn the presence of obvious peak value, then it is assumed that acquisition success, it is on the contrary, then it is assumed that capture failure.
2. according to the method for claim 1, the Doppler-frequency estimation value of calculation assumption wherein in step (3a)By such as Lower formula is carried out：
Wherein L=(fdmax-fdmin)/δf+ 1, δf=2/5TCOH, TCOHIt is the coherent accumulation cycle, fdmin=-120KHz is Doppler The minimum value of frequency estimation, fdmax=120KHz is the maximum of Doppler-frequency estimation value.
3. the method according to claim 11, wherein correlation function of the step (7) to the adjacent spreading code cycleCarry out It is cumulative, carry out as follows：
(7a) sets the correlation function in r-th of spreading code cycleFor：
WhereinIt is signalReduced form, represent complex conjugate of the local CA codes after SOQPSK is modulated, 1≤r ≤NCOH, NCOH=1,2,3... is the number for carrying out the cumulative accumulation cycle；
(7b) is by NCOHThe correlation function in individual cycleAdded up, obtained correlation function is：
CN201710494935.3A 2017-06-26 2017-06-26 FFT optimization method in high-dynamic weak continuous phase modulation signal capture Active CN107370705B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710494935.3A CN107370705B (en) 2017-06-26 2017-06-26 FFT optimization method in high-dynamic weak continuous phase modulation signal capture

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710494935.3A CN107370705B (en) 2017-06-26 2017-06-26 FFT optimization method in high-dynamic weak continuous phase modulation signal capture

Publications (2)

Publication Number Publication Date
CN107370705A true CN107370705A (en) 2017-11-21
CN107370705B CN107370705B (en) 2019-12-31

Family

ID=60305834

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710494935.3A Active CN107370705B (en) 2017-06-26 2017-06-26 FFT optimization method in high-dynamic weak continuous phase modulation signal capture

Country Status (1)

Country Link
CN (1) CN107370705B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111865363A (en) * 2020-07-13 2020-10-30 南京理工大学 High-dynamic code capture method based on conjugate frequency modulation
CN112965090A (en) * 2021-02-08 2021-06-15 南京航空航天大学 Spread spectrum CPM signal capturing method with modulation index h >1 and h being half integer
CN113422635A (en) * 2021-06-15 2021-09-21 南京邮电大学 Collision-tolerant random access method for satellite Internet of things system in high-load scene
CN114553656A (en) * 2022-02-21 2022-05-27 西安电子科技大学 Weak signal capturing method based on unequal-length double-block zero-filling algorithm

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101834632A (en) * 2010-04-16 2010-09-15 西安电子科技大学 Method for capturing synchronization in frequency hopping communication
CN103645483A (en) * 2013-12-09 2014-03-19 西安电子科技大学昆山创新研究院 Beidou signal capturing method in weak signal environment
CN104253774A (en) * 2014-09-16 2014-12-31 重庆邮电大学 System and method for estimating Doppler frequency offset under high-dynamic environment
CN104360357A (en) * 2014-11-24 2015-02-18 四川九洲电器集团有限责任公司 Quick Beidou satellite signal capturing method and system based on circulation mode
CN106547005A (en) * 2015-09-18 2017-03-29 北京大学 A kind of method and device for capturing for sinusoidal binary offset carrier (boc) modulated signals
CN106646546A (en) * 2016-12-20 2017-05-10 南京六九零二科技有限公司 Multi-dimensional fast acquisition method and system for satellite signals

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101834632A (en) * 2010-04-16 2010-09-15 西安电子科技大学 Method for capturing synchronization in frequency hopping communication
CN103645483A (en) * 2013-12-09 2014-03-19 西安电子科技大学昆山创新研究院 Beidou signal capturing method in weak signal environment
CN104253774A (en) * 2014-09-16 2014-12-31 重庆邮电大学 System and method for estimating Doppler frequency offset under high-dynamic environment
CN104360357A (en) * 2014-11-24 2015-02-18 四川九洲电器集团有限责任公司 Quick Beidou satellite signal capturing method and system based on circulation mode
CN106547005A (en) * 2015-09-18 2017-03-29 北京大学 A kind of method and device for capturing for sinusoidal binary offset carrier (boc) modulated signals
CN106646546A (en) * 2016-12-20 2017-05-10 南京六九零二科技有限公司 Multi-dimensional fast acquisition method and system for satellite signals

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
MD SOHRAB MAHMUD: "Weak GPS signal detection in the presence of strong signals with varying relative Doppler and long integration gain", 《2016 IEEE/ION POSITION,LOCATION AND NAVIGATION SYMPOSIUM(PLANS)》 *
徐晓红: "低信噪比下CPM信号捕获研究", 《中国优秀硕士学位论文全文数据库信息科技辑》 *
黄健: "高动态扩频信号的快速捕获算法研究", 《中国优秀硕士学位论文全文数据库信息科技辑》 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111865363A (en) * 2020-07-13 2020-10-30 南京理工大学 High-dynamic code capture method based on conjugate frequency modulation
CN112965090A (en) * 2021-02-08 2021-06-15 南京航空航天大学 Spread spectrum CPM signal capturing method with modulation index h >1 and h being half integer
CN113422635A (en) * 2021-06-15 2021-09-21 南京邮电大学 Collision-tolerant random access method for satellite Internet of things system in high-load scene
CN114553656A (en) * 2022-02-21 2022-05-27 西安电子科技大学 Weak signal capturing method based on unequal-length double-block zero-filling algorithm
CN114553656B (en) * 2022-02-21 2023-07-28 西安电子科技大学 Weak signal capturing method based on unequal-length double-block zero padding algorithm

Also Published As

Publication number Publication date
CN107370705B (en) 2019-12-31

Similar Documents

Publication Publication Date Title
CN110071738B (en) Spread spectrum signal despreading and tracking method based on multi-pseudo code branch receiver
Jovic et al. A robust sequence synchronization unit for multi-user DS-CDMA chaos-based communication systems
CN102710281B (en) Direct sequence spread spectrum method for continuous phase modulation
CN107370705A (en) FFT optimization method in the capture of high dynamic weakly continuous phase modulated signal
CN101110602B (en) Carrier wave catching system and method based on multimode operation
CN103580718B (en) Quick time-frequency synchronizing method under low signal-to-noise ratio
CN107493117B (en) The two-dimentional joint acquisition method of direct expansion msk signal under a kind of high dynamic
CN101969321B (en) FFT (Fast Fourier Transform) based large frequency offset secondary catching method of direct sequence spread spectrum system
CN109104390A (en) A kind of capture of high speed signal and tracking and device
CN102332933A (en) Short-term burst spread spectrum signal transmitting and receiving method
CN105141340A (en) Full-digital receiving method of direct spread MSK signal
CN105790788B (en) A kind of pseudo-code of direct expansion msk signal-Doppler's joint acquisition method
CN108401581B (en) A kind of PN code quick capturing methods in satellite spectrum-spread communication system
JP2006197375A (en) Method for receiving and receiver
CN106253945B (en) A kind of spread-spectrum signal broad sense carrier synchronization system and method for super large dynamic environment
CN108964824A (en) A kind of anti-Doppler frequency displacement synchronous method based on pseudo-random sequence differential encoding
CN102497240B (en) Sampling synchronous device and sampling synchronous method of digital broadcasting system
CN103439718B (en) Unambiguous tracking unit of high-order BOC modulation signals
CN103427871B (en) A kind of repeating jamming method suppressing Smart AGC antijamming capability
CN102638335B (en) Cross-correlation and autocorrelation cascade based frame synchronizing method
CN109474307A (en) Non-coherent spread-spectrum signal quick capturing method
CN109547060B (en) Frequency hopping spread spectrum signal transmitting device, frequency hopping spread spectrum signal receiving device, frequency hopping spread spectrum communication system and frequency hopping spread spectrum communication method
CN107247276A (en) Weak signal catching method based on overlapping polylith zero padding algorithm
CN113922843A (en) Method and system for synchronizing signals of communication system
CN101594167A (en) The method of allied signal detection and Frequency Estimation in a kind of wireless network

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