CN107359902A - A kind of PCMA Time Delay of Systems and frequency difference Fast Coarse method for catching based on frequency slots and FFT - Google Patents

A kind of PCMA Time Delay of Systems and frequency difference Fast Coarse method for catching based on frequency slots and FFT Download PDF

Info

Publication number
CN107359902A
CN107359902A CN201710580362.6A CN201710580362A CN107359902A CN 107359902 A CN107359902 A CN 107359902A CN 201710580362 A CN201710580362 A CN 201710580362A CN 107359902 A CN107359902 A CN 107359902A
Authority
CN
China
Prior art keywords
frequency
sequence
fft
time delay
pcma
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
CN201710580362.6A
Other languages
Chinese (zh)
Other versions
CN107359902B (en
Inventor
黄波
王青杰
李大鹏
李选
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.)
Nanjing Post and Telecommunication University
Nanjing University of Posts and Telecommunications
Original Assignee
Nanjing Post and Telecommunication 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 Nanjing Post and Telecommunication University filed Critical Nanjing Post and Telecommunication University
Priority to CN201710580362.6A priority Critical patent/CN107359902B/en
Publication of CN107359902A publication Critical patent/CN107359902A/en
Application granted granted Critical
Publication of CN107359902B publication Critical patent/CN107359902B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/707—Spread spectrum techniques using direct sequence modulation
    • H04B1/7073—Synchronisation aspects
    • H04B1/7075—Synchronisation aspects with code phase acquisition
    • H04B1/7077—Multi-step acquisition, e.g. multi-dwell, coarse-fine or validation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/707—Spread spectrum techniques using direct sequence modulation
    • H04B1/7073—Synchronisation aspects
    • H04B1/7075—Synchronisation aspects with code phase acquisition
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/707—Spread spectrum techniques using direct sequence modulation
    • H04B1/7097—Interference-related aspects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
    • H04J11/0023—Interference mitigation or co-ordination
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
    • H04J2011/0003—Combination with other multiplexing techniques
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
    • H04J2011/0096—Network synchronisation

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Radio Relay Systems (AREA)

Abstract

The invention discloses a kind of PCMA Time Delay of Systems and frequency difference quick capturing method based on frequency slots and FFT.First according to clock source used by satellite and earth station is long-term and short-term stability, frequency difference hunting zone is calculated, divides corresponding frequency well width and frequency slots number, and according to the hunting zone of the geometrical relationship estimation time delay between earth station and satellite；Second step：In each frequency slots, using the related relation with FFT of part non-periodic sequence, the PCMA mixed signals received and the correlation peak of local reproduction signal are calculated using FFT；3rd step：Select from all frequency slots correlation peaks modulus value maximum, and according to the threshold determination of setting whether acquisition success, otherwise just more subtly divide frequency slots.After acquisition success, slightly catch frequency difference and be accurate in a frequency slots, slightly catch time delay and be accurate to a sampling period, reduce the implementation complexity that next step frequency difference and time delay accurately capture link.The present invention effectively accelerates the time delay of PCMA systems and frequency difference slightly catches process.

Description

A kind of PCMA Time Delay of Systems and frequency difference Fast Coarse method for catching based on frequency slots and FFT
Technical field
The invention belongs to technical field of satellite communication, is related to a kind of PCMA Time Delay of Systems and frequency based on frequency slots and FFT Poor Fast Coarse method for catching.
Background technology
Paired carrier multiple access access (Paired Carrier Multiple Access, PCMA) is public by U.S. ViaSat The Mark Dankberg of department were proposed first in 1998.Being primarily directed to can be (every from ring using Transparent Transponder and signal Any one terminal that the signal that one terminal is sent can be included including itself receives) two-way satellite communication system System.Each ICBM SHF satellite terminal sends a upward signal, while receives a downstream signal, therefore each party from another terminal The downstream signal received is the superposition of intercommunication signal, and this signal is PCMA mixed signals.
Because each terminal knows for sure the upward signal transmitted by itself, and the signal that knows for sure turns Hair, processing procedure, estimate so the terminal can send the downstream signal being forwarded back to oneself, and mixed from the PCMA of superposition Offset and filter out in signal, so as to correctly recover signal and the data that other side sends.This process is referred to as PCMA self-interferences pair Disappear, and the key of PCMA systems.The thick capture of time delay and frequency difference is the important step that PCMA self-interferences offset, when it is follow-up Prolong the basis caught with frequency difference essence.
The capture of time delay and frequency difference is a two-dimensional search process, and any one deviation is excessive in both, signal all without Good correlation is shown (generally speaking, to data signal, when signal time delay is more than half of baud, the two letters Number it can show uncorrelated).And the algorithm that the Combined estimator of time delay and frequency difference is commonly used is the natural extending of correlation function, that is, Solve following ambiguity function：
Here τ, f represent time delay and frequency difference, s respectively1(t),s2(t) be comprising same composition two signals envelope, So that | A (τ, f) | reach the τ of peak value, f is exactly our time delay and frequency difference to be looked for.Therefore, whole acquisition procedure just concentrate on In the solution of upper ambiguity function.
For above formula, if f=0, above formula is exactly traditional cross-correlation function.If f ≠ 0, above formula can look at It is wherein s1After frequency spectrum shift f again with s2Do correlation.For given SNR and given input bandwidth, the time of integration, T was determined The precision that τ, f can reach.It is a low pass filter that can look at, and bandwidth is aboutBig T means narrower Filtering, lower background energy can pass through.
Definition：
For mixed product, when
It is available then to substitute into (2)：
r(t；τ)=u (t) u*(t-D)exp[j2π(f1-f2)t]exp[-j2πf2(τ-D)] (4)
Work as f1-f2When ≠ 0, it is f that the DC component of mixed product, which becomes a frequency,1-f2Sine wave.And obscure Function operatorBecome bandpass filter of the centre frequency in f, it is to mix that can also look at Rideshare accumulates one frequency f of heterodyne, then by low pass filter.As f and f1-f2It is fitted to wellWithin when, low pass Wave filter will produce a very strong output, and in f=f1-f2When reach peak value.Certainly, this also requires that delay, τ and D will Inverse of the matching in signal bandwidth wellIn the range of, so that mixed product itself also has significant amplitude.Therefore, frequency difference and The capture of time delay is a two-dimentional parallel search process, and frequency difference influences to be solved using the method for division frequency slots Certainly.In a frequency slots, can temporarily think the output of ambiguity function by when the correlation caused by time delay determine.For week Phase sequence, its autocorrelation process is asked to be realized by cycle related method, and cycle correlation can quickly be counted by FFT Calculate, this be cdma system frequently with fast Acquisition algorithm.
Signal and self-interference letters different from PN-code capture sequence used by cdma system, locally reappearing in PCMA systems Number all it is non-periodic sequence, for non-periodic sequence, it is impossible to directly using the cycle is related and DFT direct corresponding relation and then logical Cross FFT and quickly calculate correlated results.
The content of the invention
Present invention aims at the Fast Coarse for solving above-mentioned time delay and frequency difference to catch problem, it is proposed that one kind based on frequency slots and FFT PCMA time delays and frequency difference quick capturing method, the present invention are slided related related to periodic sequence circulation using partial sequence Relation, by zero padding, using circulation is related and DFT relation, quickly realize that PCMA locally reappears aperiodic using FFT The slip related operation of signal and self-interference nonperiodic signal.
The technical scheme adopted by the invention to solve the technical problem is that during a kind of PCMA systems based on frequency slots and FFT Prolong with frequency difference quick capturing method, specifically comprise the following steps：
Step 1：According to satellite and earth station's clock source be long-term and short-term stability and communication frequency, possible frequency is estimated Poor range delta F, frequency slots width Delta f is selected, and then determine division frequency slots number
Step 2：According to satellite and earth station's geometrical relationship, and estimation propagation delay (Δ t) and possible error range, and it is right Local reproduction signal carries out Δ t delays；
Step 3：Synchronization, the local reproduction signal s that length is 2N is taken respectively1(n) it is 2N's with the length received PCMA mixed signals s2(n) FFT of 2N points is done, frequency-region signal is respectively S after conversion1And S (k)2(k)；
Step 4：To S1(k) frequency shift (FS) is carried out, skew spacing is frequency slots width Delta f, obtains a series of different frequency deviations SequenceComplete the process of M frequency slots of division；
Step 5：Take respectivelyConjugation, with S2(k) conjugation multiplication is done, M conjugation is obtained and multiplies Frequency domain sequence afterwards
Step 6：The frequency-region signal for being respectively 2N to the M length obtained in step 5IFFT conversion is carried out, and takes preceding N points respectively, and is taken absolute value, is obtained The related absolute value sequence of slip for being N to M length
Step 7：From M sequenceSequence where the middle value for obtaining maximum absolute value Compared with current decision threshold, if detected successfully, capture mark is exported；Otherwise, frequency shift (FS) separation delta f, weight are reduced Newly since step 4.
Further, after time delay and frequency difference slightly catch completion, in the frequency slots chosen, it can use and divide sub- frequency slots Method is further to reduce frequency difference scope, so as to further reduce the implementation complexity that follow-up time delay and frequency difference accurately capture link Degree.
Further, signal s is locally reappeared described in step 31(n) N number of zero padding is included.
Further, the related calculating process of above-mentioned slip is as follows：
Step 1：Assuming that two non-periodic sequences for participating in computing are s respectively2And s (n)1(n), certain same moment, From s2(n) length is taken out in and blocks sequence s ' for 2N2(n)；From s1(n) length is taken out in and blocks sequence s " for N1(n), will s"1(n) N number of 0 is supplemented, forms the new sequence s ' that length is 2N1(n)=[s "1(n), zeros (1, N)], wherein zeros (1, N) N number of the 0 of supplement is represented, so far data are ready；
Step 2：Ask the transformation results of sequence, S2(k)=FFT (s '2(n), 2N), S1(k)=FFT (s '1(n), 2N), on It is to make FFT computings to data source datsrc to state FFT in expression formula (datsrc, points) function, and the points of data source are points；
Step 3：Seek S1(k) conjugationThen product is done, is obtained
Step 4：IFFT conversion is carried out,This y (n) sequence is also a 2N point Sequence, in view of above s '1(n) sequence is the sequence that rear portion mends 0, in y (n) only before N points it is effective, point below is invalid to be picked Remove, the new sequence for rejecting to obtain is designated as r (n), length N, as partial sequence related result, therefore, according to this formula, uses FFT can quickly calculate slip correlated process.
Beneficial effect：
1st, the present invention is divided by frequency slots, and the related pass related to periodic sequence circulation is slided using non-periodic sequence System, quickly calculated by FFT the non-periodic sequence that locally reappears in PCMA systems and the self-interference non-periodic sequence received it Between correlation, accelerate the time delay of PCMA systems and frequency difference slightly catch process, and realize simple.
2nd, after the present invention slightly catches process completion, frequency difference is narrowed down in a frequency slots, and time delay is accurate between a sampling Every, reduce follow-up time delay and frequency difference accurate capture and tracking link implementation complexity.
Brief description of the drawings
Fig. 1 is the inventive method flow chart.
Fig. 2 is that the inventive method implements flow chart.
Fig. 3 is that FFT of the present invention quickly calculates slip correlated results schematic diagram.
Embodiment
With reference to Figure of description, the present invention is described in further detail.
As shown in figure 1, the present invention is first according to clock source used by satellite and earth station is long-term and short-term stability, meter Frequency difference hunting zone is calculated, divides corresponding frequency well width and frequency slots number；Secondly in each frequency slots, according to earth station The distance between satellite, the hunting zone of estimation time delay, and the PCMA signals received and local reproduction signal are calculated using FFT Correlation peak, determine most probable time delay；Then in most probable time delay point, according to advanced, immediately and hysteresis three branch roads Correlation peak contrast, it is confirmed whether it is false capture, it is no just more subtly to divide frequency slots, repeat second step flow.The present invention After the two-dimentional Fast Coarse method for catching of offer is implemented, frequency difference is accurate in a frequency slots, and time delay is accurate to a sampling period, To implement frequency difference and time delay in next step, accurately capture lays a solid foundation.
The core of the present invention is to make use of the related pass between the circulation correlation of periodic sequence of the slip of non-periodic sequence It is, and then the slip correlation of non-periodic sequence is directly calculated using FFT, time delay is determined according to the position of relevant peaks.
In a frequency slots, it is with respect to another sequence by a sequence containing same section to slide related operation process Row move, the process to be added up after corresponding dot-product.The movement of sequence represents the adjustment of time delay, is adjusted in two sequence time delays After whole alignment, correlated results can be maximum, time delay can be estimated accordingly, and precision controlling is in a sampled point.Root According to relation of the slip correlation between related to circulation, and the relation of circulation correlation and Fourier transformation is combined, be based ultimately upon FFT's It is as follows to slide related specific calculating process：
Step 1：Assuming that two non-periodic sequences for participating in computing are s respectively2And s (n)1(n), certain same moment, From s2(n) length is taken out in and blocks sequence s ' for 2N2(n)；From s1(n) length is taken out in and blocks sequence s " for N1(n), will s"1(n) N number of 0 is supplemented, forms the new sequence s ' that length is 2N1(n)=[s "1(n), zeros (1, N)], wherein zeros (1, N) Represent N number of the 0 of supplement.So far, data are ready.
Step 2：Ask the transformation results of sequence, S2(k)=FFT (s '2(n), 2N), S1(k)=FFT (s '1(n), 2N), on It is to make FFT computings to data source datsrc to state FFT in expression formula (datsrc, points) function, and the points of data source are points。
Step 3：Seek S1(k) conjugationThen product is done, is obtained
Step 4：IFFT conversion is carried out,This y (n) sequence is also a 2N point Sequence, in view of above s '1(n) sequence is the sequence that rear portion mends 0, in y (n) only before N points it is effective, point below is invalid to be picked Remove, the new sequence for rejecting to obtain is designated as r (n), length N, as partial sequence related result.Therefore, according to this formula, use FFT, it can quickly calculate slip correlated process.
It is provided by the invention based on frequency slots as shown in Fig. 2 based on the slip correlation fast algorithm based on FFT Time delay and frequency difference Fast Coarse method for catching specific implementation process are as follows：
Step 1：According to satellite and earth station's clock source be long-term and short-term stability and communication frequency, possible frequency is estimated Poor scope, select frequency well width (Δ f), and then determination division frequency slots number
Step 2：According to satellite and earth station's geometrical relationship, and estimation propagation delay (Δ t) and possible error range, and it is right Local reproduction signal carries out Δ t delays；
Step 3：Synchronization, the local reproduction signal s that length is 2N is taken respectively1(n) length for (containing N number of zero padding) and receiving Spend the PCMA mixed signals s for 2N2(n) FFT of 2N points is done, frequency-region signal is respectively S after conversion1And S (k)2(k)；
Step 4：To S1(k) frequency shift (FS) is carried out, skew spacing is frequency slots width Delta f, obtains a series of different frequency deviations SequenceThis is actually the process for dividing M frequency slots；
Step 5：Take respectivelyConjugation, with S2(k) conjugation multiplication is done, M conjugation is obtained and multiplies Frequency domain sequence afterwards
Step 6：The frequency-region signal for being respectively 2N to the M length obtained in step 5IFFT conversion is carried out, and takes preceding N points respectively, and is taken absolute value, is obtained The related absolute value sequence of slip for being N to M length
Step 7：From M sequenceSequence where the middle value for obtaining maximum absolute value Compared with current decision threshold.If detected successfully, capture mark is exported；Otherwise, frequency shift (FS) separation delta f, weight are reduced Newly since step 4.
Step 8：It is optional, after acquisition success, appropriate sub- frequency slots can be further divided in the frequency slots of capture, Step 4 is returned to, further reduces the scope of frequency difference.
After Fig. 3 shows that the inventive method is implemented, quickly calculated with FFT/IFFT in a frequency slots aperiodic Sequence slides correlated results schematic diagram.It is clear that from figure, correlation peak appears in the 500th sampled point, that is, The time delay of local reproduction signal and PCMA mixed signals (in interference signal) is 500 sampling intervals, and this is with being manually set Time delay matches completely.Demonstrate the validity and correctness of method.

Claims (4)

1. a kind of PCMA Time Delay of Systems and frequency difference quick capturing method based on frequency slots and FFT, it is characterised in that methods described Comprise the following steps：
Step 1：According to satellite and earth station's clock source be long-term and short-term stability and communication frequency, possible frequency difference model is estimated Δ F is enclosed, selects frequency slots width Delta f, and then determines division frequency slots number
Step 2：According to satellite and earth station's geometrical relationship, estimation propagation delay (Δ t) and possible error range, and to local Reappear signal and carry out Δ t delays；
Step 3：Synchronization, the local reproduction signal s that length is 2N is taken respectively1(n) PCMA for being 2N with the length received is mixed Signal s2(n) FFT of 2N points is done, frequency-region signal is respectively S after conversion1And S (k)2(k)；
Step 4：To S1(k) frequency shift (FS) is carried out, skew spacing is frequency slots width Delta f, obtains a series of sequence of different frequency deviationsComplete the process of M frequency slots of division；
Step 5：Take respectivelyConjugation, with S2(k) conjugation multiplication is done, obtains frequency after M conjugation multiplies Domain sequence
Step 6：The frequency-region signal for being respectively 2N to the M length obtained in step 5IFFT conversion is carried out, and takes preceding N points respectively, and is taken absolute value, Obtain the related absolute value sequence of slip that M length is N
Step 7：From M sequenceSequence where the middle value for obtaining maximum absolute valueWith it is current Decision threshold is compared, if detected successfully, exports capture mark；Otherwise, frequency shift (FS) separation delta f is reduced, again from step Rapid 4 start.
2. a kind of PCMA Time Delay of Systems and frequency difference Fast Coarse method for catching based on frequency slots and FFT according to claim 1, Characterized in that, after time delay and frequency difference slightly catch completion, in the frequency slots chosen, the method for dividing sub- frequency slots can be used Further to reduce frequency difference scope, so as to further reduce the implementation complexity that follow-up time delay and frequency difference accurately capture link.
3. a kind of PCMA Time Delay of Systems and frequency difference Fast Coarse method for catching based on frequency slots and FFT according to claim 1, Characterized in that, locally reappear signal s described in step 31(n) N number of zero padding is included.
4. a kind of PCMA Time Delay of Systems and frequency difference Fast Coarse method for catching based on frequency slots and FFT according to claim 1, Characterized in that, the calculating process of the slip correlation is as follows：
Step 1：Assuming that two non-periodic sequences for participating in computing are s respectively2And s (n)1(n), certain same moment, from s2 (n) length is taken out in and blocks sequence s' for 2N2(n)；From s1(n) length is taken out in and blocks sequence s " for N1(n), by s "1 (n) N number of 0 is supplemented, forms the new sequence s ' that length is 2N1(n)=[s "1(n), zeros (1, N)], wherein zeros (1, N) is represented N number of the 0 of supplement, so far data are ready；
Step 2：Ask the transformation results of sequence, S2(k)=FFT (s'2(n), 2N), S1(k)=FFT (s '1(n), 2N), above-mentioned expression FFT (datsrc, points) function is to make FFT computings to data source datsrc in formula, and the points of data source are points；
Step 3：Seek S1(k) conjugationThen product is done, is obtained
Step 4：IFFT conversion is carried out,This y (n) sequence is also the sequence of a 2N point Row, in view of above s '1(n) sequence is the sequence that rear portion mends 0, in y (n) only before N points it is effective, point below is invalid to be removed, Reject obtained new sequence and be designated as r (n), length N, as partial sequence related result, therefore, according to this formula, using FFT Slip correlated process can quickly be calculated.
CN201710580362.6A 2017-07-17 2017-07-17 A kind of quick thick method for catching of PCMA Time Delay of Systems and frequency difference based on frequency slots and FFT Active CN107359902B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710580362.6A CN107359902B (en) 2017-07-17 2017-07-17 A kind of quick thick method for catching of PCMA Time Delay of Systems and frequency difference based on frequency slots and FFT

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710580362.6A CN107359902B (en) 2017-07-17 2017-07-17 A kind of quick thick method for catching of PCMA Time Delay of Systems and frequency difference based on frequency slots and FFT

Publications (2)

Publication Number Publication Date
CN107359902A true CN107359902A (en) 2017-11-17
CN107359902B CN107359902B (en) 2019-08-02

Family

ID=60292261

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710580362.6A Active CN107359902B (en) 2017-07-17 2017-07-17 A kind of quick thick method for catching of PCMA Time Delay of Systems and frequency difference based on frequency slots and FFT

Country Status (1)

Country Link
CN (1) CN107359902B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108923877A (en) * 2018-07-02 2018-11-30 成都国恒空间技术工程有限公司 A kind of PCMA timing acquisition and tracking
CN109586835A (en) * 2018-10-19 2019-04-05 四川安迪科技实业有限公司 A kind of continuous pairs multiple-access communication control processor self-interference canceller synchronous method
CN111245473A (en) * 2020-01-16 2020-06-05 电子科技大学 Down-sampling-serial FFT-based high-dynamic low-signal-to-noise-ratio signal coarse capturing method

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107425904A (en) * 2017-07-17 2017-12-01 南京邮电大学 A kind of PCMA Time Delay of Systems and frequency difference Fast Coarse method for catching based on frequency slots and FFT

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106656400A (en) * 2016-10-21 2017-05-10 南京邮电大学 Accurate frequency difference fast acquisition method in time delay jitter condition of PCMA system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106656400A (en) * 2016-10-21 2017-05-10 南京邮电大学 Accurate frequency difference fast acquisition method in time delay jitter condition of PCMA system

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
BO HUANG: "Performance Analysis of NCLMS-based PCMA", 《2016 3RD INTERNATIONAL CONFERENCE ON INFORMATION SCIENCE AND CONTROL ENGINEERING》 *
刘征，汪春霆: "一种实现PCMA信号快速捕获的方法", 《无线电工程》 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108923877A (en) * 2018-07-02 2018-11-30 成都国恒空间技术工程有限公司 A kind of PCMA timing acquisition and tracking
CN109586835A (en) * 2018-10-19 2019-04-05 四川安迪科技实业有限公司 A kind of continuous pairs multiple-access communication control processor self-interference canceller synchronous method
CN111245473A (en) * 2020-01-16 2020-06-05 电子科技大学 Down-sampling-serial FFT-based high-dynamic low-signal-to-noise-ratio signal coarse capturing method
CN111245473B (en) * 2020-01-16 2021-04-30 电子科技大学 Down-sampling-serial FFT-based high-dynamic low-signal-to-noise-ratio signal coarse capturing method

Also Published As

Publication number Publication date
CN107359902B (en) 2019-08-02

Similar Documents

Publication Publication Date Title
CN107359902B (en) A kind of quick thick method for catching of PCMA Time Delay of Systems and frequency difference based on frequency slots and FFT
CN102065048B (en) Time-domain joint estimation method for synchronizing frames, frequencies and fine symbols for orthogonal frequency division multiplexing (OFDM)
CN105635002B (en) A kind of synchronous estimation method and receiving device
CN105141562B (en) Communication system and its synchronous method
CN104641610B (en) Method and apparatus for estimating frequency error
CN110071738A (en) Spread-spectrum signal based on more pseudo-code branch receivers de-spreads tracking
CN103580718A (en) Quick time-frequency synchronizing method under low signal-to-noise ratio
JP2007282233A (en) Signal frame, method for synchronizing the same, transmitter and receiver of telecommunications system, and the telecommunications system
CN105607096A (en) Dual-satellite time difference and frequency difference positioning method and positioning device
WO2015070820A1 (en) Spread spectrum signal generating method, generating apparatus, receiving method and receiving apparatus
CN109743073A (en) Big frequency deviation Direct Sequence Spread Spectrum fast synchronization method based on unique code
CN109756968A (en) The precise synchronization timing method and precise synchronization timing means of single carrier spread spectrum system
CN102497240B (en) Sampling synchronous device and sampling synchronous method of digital broadcasting system
CN104052555B (en) A kind of method of radio channel multi-path parameter Estimation under ofdm system
CN107425904A (en) A kind of PCMA Time Delay of Systems and frequency difference Fast Coarse method for catching based on frequency slots and FFT
CN107623647B (en) Carrier synchronization method based on scattered pilot frequency assistance
CN105445767B (en) BOC signal parameter blind estimating methods based on average Ambiguity Function
CN106656400A (en) Accurate frequency difference fast acquisition method in time delay jitter condition of PCMA system
CN107370705A (en) FFT optimization method in the capture of high dynamic weakly continuous phase modulated signal
CN104199064B (en) Correlation fluctuation based BOC (binary offset carrier) signal parameter blind estimation method
CN110445740A (en) Frequency deviation estimating method and system based on repetitive sequence
CN107276953B (en) Timing synchronization method, device and system
CN102624514A (en) Method for improving timing synchronous precision of wireless channel measurement
CN107276927B (en) Channel estimation method and device
Kohda et al. PLL-free receiver for Gabor division/spread spectrum system

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