CN106501787B - Coded Signals method for parameter estimation based on smooth pseudo derivative feedback - Google Patents
Coded Signals method for parameter estimation based on smooth pseudo derivative feedback Download PDFInfo
- Publication number
- CN106501787B CN106501787B CN201610952840.7A CN201610952840A CN106501787B CN 106501787 B CN106501787 B CN 106501787B CN 201610952840 A CN201610952840 A CN 201610952840A CN 106501787 B CN106501787 B CN 106501787B
- Authority
- CN
- China
- Prior art keywords
- coded signals
- power spectrum
- signal
- sequence
- undershoot
- 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.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
The present invention relates to a kind of Coded Signals method for parameter estimation based on smooth pseudo derivative feedback, mainly solve the problems, such as that existing method cannot take into account low signal-to-noise ratio and small calculation amount.Implementation step is: 1) generating the Coded Signals of 13 Barker code sequential codings；2) its power spectrum is found out as FFT transform to Coded Signals；3) power spectrum is smoothed, and signal carrier frequency is estimated according to the three dB bandwidth power spectrum center of gravity of smooth rear power spectrum；4) smooth pseudo derivative feedback transformation is carried out to Coded Signals, obtains the amplitude sequence at carrier frequency；5) search amplitude sequence minimum undershoot spacing obtains signal element width, and calculates the subcode number that adjacent undershoot is included；6) according to undershoot position and subcode number, the estimation of sequence of symhols is obtained.The present invention improves the estimated accuracy to the parameter of Coded Signals in low signal-to-noise ratio, reduces calculation amount, can be used for the accurate scouting to target.
Description
Technical field
The invention belongs to technical field of data processing, in particular to the two-phase of a kind of smooth pseudo derivative feedback SPWVD is compiled
Code bpsk signal method for parameter estimation, the accurate scouting that can be used in low probability of intercept radar to target.
Background technique
In order to reduce average emitted power, the probability that signal is trapped is reduced, low probability of intercept radar, which generallys use, to be had
The pulse compression signal of broadband product when big.Phase-coded signal due to distance resolution with higher and it is stronger it is anti-scout,
Anti-interference ability and become a kind of common pulse compression signal.Due to the echo-signal that radar receives often be buried in it is big
In noise background, therefore, when using digital received, the phase of phase-coded signal how is rapidly estimated under low signal-to-noise ratio
Parameter is closed to have important practical significance.
For the Parameter Estimation Problem of bpsk signal, Wujiang mark, incomparably, Yu Chunlai is proposed " based on Wavelet Transform
Aerospace electronic warfare is shown in phase-coded signal intrapulse feature extraction ", 2005 (3): 38-40, extracts in text with wavelet transformation small
The method of wave crest line identifies phase-coded signal, and under low signal-to-noise ratio conditions the extraction of wavelet ridge is influenced by noise
It is very big, Signal parameter estimation precision is influenced, and this method operand is big, is not suitable for engineer application；Yin Jihao, Wang Ling, Chen Tian
Qi proposes " a kind of multiple Coded Signals carrier frequency, code rate and coded sequence estimation method " and sees signal processing, and 2006,22
(5): 639-543, with Time-Frequency Analysis Method-Short Time Fourier Transform STFT to the code element information and coding of bpsk signal in text
Sequence is estimated, but the noiseproof feature of STFT is poor, low to Signal parameter estimation precision in the environment of low signal-to-noise ratio；Lv Ming
Long, Zhou Ming, Han Jun, Deng Jing propose " a kind of low signal-to-noise ratio Coded Signals Time-Frequency Analysis Method " and see radar science and skill
2010 (6): art proposes to carry out dual threshold Singularity detection, the party again to the transformed result of signal STFT in 549-552. text
Although method realizes the parameter Estimation to bpsk signal under low signal-to-noise ratio conditions, but estimated accuracy is low, and is estimating
Process needs to accumulate pulse, and the required processing time is long, computationally intensive.
Summary of the invention
It is an object of the invention to be directed to the deficiency of above-mentioned existing method, propose a kind of based on smooth pseudo derivative feedback
Coded Signals method for parameter estimation, to improve under Low SNR to biphase coding bpsk signal carrier frequency, code is wide and
The estimated accuracy of coded sequence, while reducing calculation amount.
To achieve the goals above, technical solution of the present invention includes the following:
(1) biphase coding encoded by 13 Barker code sequences [1 111 1-1-1 1 1-1 1-1 1] is generated
Signal s (t)；
(2) FFT transform is carried out to Coded Signals s (t), obtains its power spectrum Y (m)；
(3) power spectrum Y (m) is smoothed, obtains smoothed out power spectrum Ys(k)；
(4) according to smooth rear power spectrum Ys(k) three dB bandwidth power spectrum center of gravity, estimates signal carrier frequency
(5) amplitude sequence is obtained
Smooth pseudo derivative feedback SPWVD 5a) is carried out to Coded Signals s (t) to convert, and obtains two-dimentional amplitude-frequency matrix
SPWVD (t, f),
Two-dimentional amplitude-frequency matrix SPWVD (t, f) is scanned in frequency dimension 5b), obtains signal carrier frequencyThe amplitude sequence at place
Column
(6) symbol width of Coded Signals s (t) is calculated
6a) search for amplitude sequenceEach undershoot position is obtained, adjacent undershoot interval delta is calculated；
Minimum adjacent undershoot interval delta 6b) is taken to be denoted as Δmin, then the estimated value of signal element widthAre as follows:
Wherein, TsFor signal sampling period；
(7) the subcode number l:l=Δ/Δ for being included by every segment data that undershoot separates is calculatedmin；
(8) sequence of symhols of Coded Signals is calculated
8a) according to undershoot position and the subcode number l for being included by every segment data that undershoot separates, estimate roughly
Count out sequence of symhols
8b) to the sequence of symhols roughly estimatedThe accurate estimation of sequence of symhols is obtained according to following formula device
Wherein, | | | | it is to take norm operation,It is the signal carrier frequency by estimatingSymbol widthSequence of symholsAnd the Coded Signals that time t is reconfigured out, argmin are to take optimal solution.
The invention has the following advantages over the prior art:
1, frequency estimation accuracy is high
The present invention is filtered the power spectrum of biphase coding bpsk signal using improved power spectrum smoothing formula,
And signal carrier frequency is estimated according to the three dB bandwidth center of gravity of smooth rear power spectrum, compared with the prior art to time-frequency matrix maximum value
Sequence is averaged the method to estimate carrier frequency, improves and estimates under Low SNR to the carrier frequency of biphase coding bpsk signal
Count precision.
2, the estimated accuracy of symbol width is high
The present invention is converted using smooth pseudo derivative feedback SPWVD estimates the symbol width of Coded Signals,
Compared with the prior art using the method for ZAM transformation, SPWVD transformation has better time-frequency locality, improves in low noise
To the symbol width estimated accuracy of Coded Signals than under the conditions of.
3, calculation amount is small
The present invention is converted using smooth pseudo derivative feedback SPWVD the phase information of Coded Signals being mapped as signal
Amplitude information at carrier frequency, the method for using Short Time Fourier Transform compared with the prior art, to the parameter of Coded Signals
Estimation does not need repeatedly to accumulate data and multiple threshold decisions, reduces calculation amount.
The present invention is described in further details with reference to the accompanying drawings and detailed description.
Detailed description of the invention
Fig. 1 is implementation flow chart of the invention；
Fig. 2 is the frequency estimation accuracy of the Coded Signals obtained with the present invention with signal-to-noise ratio change curve；
Fig. 3 is that the symbol width estimated accuracy of the Coded Signals obtained with the present invention with existing method becomes with signal-to-noise ratio
Change curve comparison figure.
Specific embodiment
Referring to Fig.1, steps are as follows for realization of the invention:
Step 1: obtaining Coded Signals s (t).
It is generated as follows by the two of 13 Barker code sequences [1 111 1-1-1 1 1-1 1-1 1] coding
Phase encoded signal s (t):
Wherein, SNR is signal-to-noise ratio, fcFor carrier frequency, t is the time, and τ is echo delay, TPFor symbol width, n is Barker code sequence
Column length, φ are initial phase, φiFor the phase of each subpulse, for Coded Signals, φi∈ { 0, π }, works as Barker code
When the symbol of sequence is 1, φiIt is taken as π, when the symbol of Barker code sequence is -1, φi0 is taken as,Be width be TPRectangle
Window function, n (t) are the Gaussian sequence being randomly generated.
Step 2: obtaining the power spectrum Y (m) of Coded Signals s (t).
FFT transform 2a) is carried out to Coded Signals s (t), the result F [s (t)] after obtaining FFT transform, transformation for mula
It is as follows:
Wherein, f is frequency；
2b) according to the result F [s (t)] after FFT transform, the power spectrum Y (m) of Coded Signals s (t) is obtained:
Wherein, T is the time span of Coded Signals s (t), and m is the length serial number that signal carries out FFT transform.
Step 3: obtaining smoothed out power spectrum Ys(k)。
Power spectrum Y (m) is smoothed, smoothed out power spectrum signal Y is obtaineds(k):
Wherein, M is smooth length, and k is spectral line serial number.
Step 4: calculating the carrier frequency of Coded Signals s (t)
4a) set Ys(k) maximum amplitude is Y ins(k0), calculate Ys(k) power spectrum center of gravity in three dB bandwidth
Wherein, L Ys(k) all in be greater than 0.5Ys(k0) spectral line quantity, k be three dB bandwidth in spectral line serial number；
4b) willCarrier frequency of the corresponding frequency as estimation
Wherein, TsFor the sampling period.
Step 5: obtaining amplitude sequence
Smooth pseudo derivative feedback SPWVD 5a) is carried out to Coded Signals s (t) to convert, and obtains two-dimentional amplitude-frequency matrix
SPWVD (t, f):
Wherein, g (τ) is time domain window function, and h (τ) is frequency domain window function, s*It (t) is the multiple total of Coded Signals s (t)
Conjugate signal；
Two-dimentional amplitude-frequency matrix SPWVD (t, f) is scanned in frequency dimension 5b), obtains carrier frequencyThe amplitude sequence at place
Step 6: calculating the symbol width of Coded Signals s (t)
6a) search for amplitude sequenceEach undershoot position is obtained, and is calculated between adjacent undershoot
Every Δ,
Minimum adjacent undershoot interval 6b) is taken to be denoted as Δmin, then the estimated value of signal element widthAre as follows:
Wherein, TsFor signal sampling period.
Step 7: calculating the subcode number l:l=Δ/Δ for being included by every segment data that undershoot separatesmin。
Step 8: calculating the sequence of symhols of Coded Signals
8a) according to undershoot position and the subcode number l for being included by every segment data that undershoot separates, estimate roughly
Count out sequence of symhols
8b) to the sequence of symhols roughly estimatedThe accurate estimation of sequence of symhols is obtained according to following formula
Wherein, | | | | it is to take norm operation,It is the signal carrier frequency by estimatingSymbol widthSequence of symholsAnd the Coded Signals that time t is reconfigured out, argmin are to take optimal solution.
Effect of the invention can pass through following emulation further verifying.
1. experiment scene:
Radar return signal is by the two of 13 Barker code sequences [1 111 1-1-1 1 1-1 1-1 1] coding
Phase encoded signal s (t), signal carrier frequency f0=75MHz, code rate fb=7.5MHz, sample frequency fs=300MHz is received in signal
The noise of aliasing is the white Gaussian noise that mean value is 0, variance is 1.In the experiment of estimation Coded Signals carrier frequency, power spectrum
Smooth points are selected as 20, and in the experiment of estimation signal element width and sequence of symhols, selection signal-to-noise ratio is -7dB, Smoothing Pseudo Wei
The window function of Ge Na distribution SPWVD and ZAM distribution is selected as Hamming window, and long window is respectively 33 and 65.
2. experiment content and result:
Experiment 1, with method of the invention in the estimation to Coded Signals carrier frequency, pass through 500 Monte Carlo realities
It tests emulation and obtains signal frequency estimation accuracy under different signal-to-noise ratio as a result, as shown in Figure 2.
Figure it is seen that frequency estimation accuracy can be up to 96% when signal-to-noise ratio is -8dB, illustrate side of the invention
The case where method is suitable for low signal-to-noise ratio for the estimation of signal carrier frequency.
Experiment 2, with the method for the present invention to estimation signal element width estimation in, pass through 500 Monte Carlo Experiments
Emulation has obtained the signal element width estimated accuracy under different signal-to-noise ratio as a result, as shown in Figure 3.
From figure 3, it can be seen that when letter is than being -7dB, estimation of the SPWVD converter technique that the present invention uses to symbol width
Precision is up to 91%, and the ZAM transformation that the prior art uses only has 74% to the estimated accuracy of symbol width, illustrates the method for the present invention
Existing method is better than to the symbol width estimated accuracy of Coded Signals under low signal-to-noise ratio conditions.
Claims (5)
1. the Coded Signals method for parameter estimation based on smooth pseudo derivative feedback, comprising:
(1) the Coded Signals s encoded by 13 Barker code sequences [1 111 1-1-1 1 1-1 1-1 1] is generated
(t)；
(2) FFT transform is carried out to Coded Signals s (t), obtains its power spectrum Y (m)；
(3) power spectrum Y (m) is smoothed, obtains smoothed out power spectrum Ys(k)；
(4) according to smooth rear power spectrum Ys(k) three dB bandwidth power spectrum center of gravity, estimates signal carrier frequency
(5) amplitude sequence is obtained
Smooth pseudo derivative feedback SPWVD 5a) is carried out to Coded Signals s (t) to convert, and obtains two-dimentional amplitude-frequency matrix SPWVD
(t, f),
Two-dimentional amplitude-frequency matrix SPWVD (t, f) is scanned in frequency dimension 5b), obtains signal carrier frequencyThe amplitude sequence at place
(6) symbol width of Coded Signals s (t) is calculated
6a) search for amplitude sequenceEach undershoot position is obtained, adjacent undershoot interval delta is calculated；
Minimum adjacent undershoot interval delta 6b) is taken to be denoted as Δmin, then the estimated value of signal element widthAre as follows:
Wherein, TsFor signal sampling period；
(7) the subcode number l:l=Δ/Δ for being included by every segment data that undershoot separates is calculatedmin；
(8) sequence of symhols of Coded Signals is calculated
8a) according to undershoot position and the subcode number l for being included by every segment data that undershoot separates, roughly estimate
Sequence of symhols
8b) to the sequence of symhols roughly estimatedThe accurate estimation of sequence of symhols is obtained according to following formula device
Wherein, | | | | it is to take norm operation,It is the signal carrier frequency by estimatingSymbol widthCode
MetasequenceAnd the Coded Signals that time t is reconfigured out, arg min are to take optimal solution.
2. according to the method described in claim 1, the Coded Signals s (t) that radar receives in its step (1), indicates
It is as follows:
Wherein, SNR is signal-to-noise ratio, fcFor carrier frequency, t is the time, and τ is echo delay, TPFor symbol width, n is that Barker code sequence is long
Degree, φ is initial phase, φiFor the phase of each subpulse, for Coded Signals, φi∈ { 0, π }, when symbol is 1,
φiIt is taken as π, when symbol is -1, φi0 is taken as,Be width be TPRectangular window function, n (t) is the white Gaussian being randomly generated
Noise sequence.
3. according to the method described in claim 1, wherein step (3) is carried out to the power spectrum Y (m) of Coded Signals s (t)
Smoothing processing carries out as follows:
Wherein, M is smooth length, and k is spectral line serial number, and m is the length serial number that signal carries out FFT transform, YsIt (k) is smooth rear function
Rate spectrum.
4. according to the method described in claim 1, according to smooth rear power spectrum Y in its step (4)s(k) three dB bandwidth power spectrum
Center of gravity estimation signal carrier frequencyIt carries out as follows:
4a) set smooth rear power spectrum Ys(k) maximum amplitude is Ys(k0), calculate Ys(k) power spectrum center of gravity in three dB bandwidth
Wherein, L Ys(k) all in be greater than 0.5Ys(k0) spectral line quantity, k be three dB bandwidth in spectral line serial number；
4b) by power spectrum center of gravity in three dB bandwidthSignal carrier frequency of the corresponding frequency as estimation
Wherein, TsFor signal sampling period.
5. according to the method described in claim 1, carrying out Smoothing Pseudo Wigner point to Coded Signals s (t) in its step (5)
Cloth SPWVD transformation, the transformation formula is as follows:
Wherein, g (τ) is time domain window function, and h (τ) is frequency domain window function, s*(t) believe for the complex conjugate of Coded Signals s (t)
Number, τ is echo delay.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610952840.7A CN106501787B (en) | 2016-11-02 | 2016-11-02 | Coded Signals method for parameter estimation based on smooth pseudo derivative feedback |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610952840.7A CN106501787B (en) | 2016-11-02 | 2016-11-02 | Coded Signals method for parameter estimation based on smooth pseudo derivative feedback |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106501787A CN106501787A (en) | 2017-03-15 |
| CN106501787B true CN106501787B (en) | 2019-03-08 |
Family
ID=58321287
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610952840.7A Active CN106501787B (en) | 2016-11-02 | 2016-11-02 | Coded Signals method for parameter estimation based on smooth pseudo derivative feedback |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106501787B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107490722A (en) * | 2017-08-18 | 2017-12-19 | 南开大学 | A kind of frequency estimating methods of low signal-to-noise ratio real signal |
| CN110113075B (en) * | 2018-10-29 | 2021-02-12 | 西安电子科技大学 | Hybrid network station frequency hopping parameter blind estimation method based on STFT-SPWVD |
| CN111798532B (en) * | 2020-08-03 | 2021-03-16 | 广州市宝绅科技应用有限公司 | Screen coding method and system based on centroid coincidence |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103441975A (en) * | 2013-08-30 | 2013-12-11 | 天津理工大学 | Two-phase coding signal parameter estimation method based on power spectrum |
| CN105158756A (en) * | 2015-08-27 | 2015-12-16 | 电子科技大学 | Centralized MIMO radar radio frequency stealth multi-target tracking wave beam pointing method |
| CN105652248A (en) * | 2014-11-10 | 2016-06-08 | 中国船舶重工集团公司第七二三研究所 | Radar signal micro feature analysis system based on digital filtering and time-frequency analysis |
| CN105866758A (en) * | 2016-03-31 | 2016-08-17 | 西安电子科技大学 | Time frequency double feature sea surface small target detection method based on block whitening clutter suppression |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2422210B1 (en) * | 2009-04-23 | 2013-09-11 | Groupe des Ecoles de Telecommunications Ecole National Superieure des Telecommunications | Orientation and localization system |
-
2016
- 2016-11-02 CN CN201610952840.7A patent/CN106501787B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103441975A (en) * | 2013-08-30 | 2013-12-11 | 天津理工大学 | Two-phase coding signal parameter estimation method based on power spectrum |
| CN105652248A (en) * | 2014-11-10 | 2016-06-08 | 中国船舶重工集团公司第七二三研究所 | Radar signal micro feature analysis system based on digital filtering and time-frequency analysis |
| CN105158756A (en) * | 2015-08-27 | 2015-12-16 | 电子科技大学 | Centralized MIMO radar radio frequency stealth multi-target tracking wave beam pointing method |
| CN105866758A (en) * | 2016-03-31 | 2016-08-17 | 西安电子科技大学 | Time frequency double feature sea surface small target detection method based on block whitening clutter suppression |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106501787A (en) | 2017-03-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107576943B (en) | Adaptive Time and Frequency Synchronization compression method based on Rayleigh entropy | |
| CN104678372B (en) | OFDM radar super-resolution distance and angle value combined estimation method | |
| CN106501787B (en) | Coded Signals method for parameter estimation based on smooth pseudo derivative feedback | |
| CN102680948A (en) | Method for estimating modulation frequency and starting frequency of linear frequency-modulated signal | |
| CN110133598B (en) | FrFT-based quick estimation method for parameters of linear frequency modulation signals | |
| CN102788969A (en) | Sea surface micromotion target detection and feature extraction method based on short-time fractional Fourier transform | |
| CN110275158A (en) | Wideband radar echo-signal method for parameter estimation based on Bayes's compressed sensing | |
| CN103675758B (en) | A kind of Hyperbolic Frequency Modulation signal period slope and initial frequency method of estimation | |
| CN110988834B (en) | Pulse arrival time measuring method based on self-adaptive threshold value double thresholds | |
| CN101944926A (en) | Compressed sampling based estimating method of arrival time of pulse ultra-wide band signal | |
| CN106772270A (en) | The method of sampling and reconstructing method of a kind of radar echo signal | |
| CN108226934A (en) | A kind of Underwater Moving Target detection method based on compressed sensing | |
| CN108169739A (en) | The linear frequency modulation continuous wave time width rate estimation detected based on fraction Fourier conversion and minimum pulse width | |
| CN107167777B (en) | Sawtooth wave linear frequency-modulated parameter extracting method | |
| CN106569182B (en) | Phase-coded signal carrier frequency estimation method based on minimum entropy | |
| CN108333568A (en) | Wideband echoes Doppler and delay time estimation method based on Sigmoid transformation under impulsive noise environment | |
| JP4779128B2 (en) | Bistatic radar device | |
| CN116299166B (en) | Low-complexity fusion ranging method for chirp signals | |
| CN104320360B (en) | A kind of linear FM signal delay time estimation method based on Fourier Transform of Fractional Order | |
| CN108337205B (en) | BPSK signal undersampling parameter estimation method based on multi-channel feedback structure | |
| CN110632563A (en) | Intra-pulse frequency coding signal parameter measuring method based on short-time Fourier transform | |
| CN108111452B (en) | Method for estimating arrival time of broadband linear frequency modulation pulse signal | |
| CN110441749A (en) | Frequency stepping radar target motion parameter estimation method | |
| CN113259027B (en) | Method for calculating hostile-my identification signal code rate based on Haar transform | |
| CN103441975B (en) | A kind of Coded Signals parameter estimation method based on power spectrum |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | 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 |