CN104914435B

CN104914435B - A kind of wind profile radar phase coding method and circuit based on Fei Lanke codes

Info

Publication number: CN104914435B
Application number: CN201510246665.5A
Authority: CN
Inventors: 沈江林; 任迎新; 孙祥; 史永辉; 郭维克
Original assignee: Beijing Institute of Radio Measurement
Current assignee: Beijing Institute of Radio Measurement
Priority date: 2015-05-14
Filing date: 2015-05-14
Publication date: 2017-03-29
Anticipated expiration: 2035-05-14
Also published as: CN104914435A

Abstract

The present invention relates to the Waveform Design of wind profile radar, signal transacting, Waveform generating method and frequency synthesis circuit technical field.Present invention firstly provides a kind of wind profile radar phase coding method and circuit based on Fei Lanke codes.The step of methods described, includes:Calculation code subpulse number M, calculates time domain accumulation number N_c, select code period number N, adjustment time domain accumulation number N_cWith code period number N, encoder matrix F is formed_N′_×M, use encoder matrix F_N′_×MCarry out the exomonental phase code of code period.Wind profile radar is used for the weather informations such as wind direction, wind speed and the echo strength of atmospheric sounding wind field, and prior art realizes the resolving power of the energy and burst pulse of broad pulse simultaneously using two-phase mutual-complementing code or using walsh function code equiphase coding techniques.The coding method of the present invention and circuit can adopt normal pulsed or burst waveforms, and with low distance side lobe, subpulse number selects flexible, can be used for antagonism point frequency radio interference, it is adaptable to various wind profile radars.

Description

A kind of wind profile radar phase coding method and circuit based on Fei Lanke codes

Technical field

The invention discloses a kind of wind profile radar phase coding method and circuit based on Fei Lanke codes, is related to Wind outline The Waveform Design of radar, signal transacting, Waveform generating method and frequency synthesis circuit technical field.

Background technology

Wind profile radar, based on clear-air turbulence detection, is a kind of weather radar.Wind profile radar mainly uses air Scattering (Bragg diffraction) effect of the turbulent flow to electromagnetic wave is detected to physical quantitys such as atmospheric winds and is obtained the number such as Wind outline According to.Wind profile radar surveys wind facies ratio with traditional ball that has, it is possible to obtain the basic number of continuous high time-space resolution power in real time According to.

Wind profile radar typically using the working system of the full coherent pulse radar of phased array, is detected using five wave beams in turn, The radial direction wind speed of each wave beam is measured, vector project is carried out and is calculated wind direction and wind speed and other data products and figure product Product.

Difference of the wind profile radar according to maximum probe height, is divided into boundary layer wind-profile radar, troposphere Wind outline thunder Up to stratosphere wind profile radar.The operating frequency in boundary layer mostly is L-band, and tropospheric operating frequency mostly is pattern-band, advection The mostly uhf band of layer.Wind profile radar is divided into fixed, packaged type according to mounting means, and packaged type is divided into vehicle-mounted again Formula and square cabinet type.

The signal transacting of wind profile radar, mainly complete the time domain accumulation to atmospheric turbulance echo-signal, pulse pressure, go it is miscellaneous Ripple, analysis of spectrum and spectrum accumulation, for obtaining the wind field information such as wind direction and wind speed.In the coherent processing of Wind profile radar signal process Include multiple radar periods in time, the signal analysis of wave beam radial velocity, time domain accumulation are generally carried out using 512 points of FFT , generally between 30 to 200, between the 20 μ S of μ S to 240, maximum probe height is between 2km to 25km, high for radar period for number Degree resolution ratio is generally between 60m to 480m.

Wind profile radar is typically a kind of full coherent pulse wind profile radar, and the Doppler frequency of atmosphere target is relatively low, visits Limited height is surveyed, the repetition period of radar is shorter, and sample rate is higher, not serious apart from image problem, and Jing can often ignore.It is this Full coherent pulse wind profile radar is generally i.e. without range ambiguity also without velocity ambiguity problem.The matching of impulse waveform is received, can be with Ignore Doppler effect, i.e., doppler information need not be extracted in a radar period and how general be extracted between radar period Le information, carries out spectrum analysis using the echo-signal of multicycle, extracts the Doppler frequency of atmosphere target.

As the Doppler frequency of atmosphere target is relatively low, the repetition period of radar is shorter, and sample rate is higher, therefore during coherent The interior radar period number for extracting doppler information is larger, i.e. coherent sample number is larger.Coherent sample number is larger to be caused The input data amount of spectrum analysis is too big.In order to reduce data volume, spectrum analysis is made to reduce operand, the signal of wind profile radar Process and (segmentation is cumulative to be averaging) is processed using time domain accumulation generally, after time domain accumulation, (length is to obtain each data segment Time domain accumulates number N_c) mean value, these sample means are being carried out with speed FFT spectrum analysis.Cycle in the coherent time Number accumulates number N for time domain_cWith FFT points Ns_FFTProduct N_cN_FFT。

It is this first to carry out time domain accumulation, the method for laggard scanning frequency degree FFT spectrum analysis, computationally can be understood as reducing The fast algorithm of amount of calculation, with signal transacting from the viewpoint of, it can be understood as time domain accumulation time in do not carry out Doppler The extraction of information, and a sample mean is extracted, doppler information is being extracted with multiple sample means.

The sample of the distance by radar unit gathered by the radar period in time domain integration time, it is believed that Doppler effect Less, approximately equal carries out phase such that it is able to the multiple cycles within the time domain integration time for the radar return phase place change that causes Position coding.A cycle cannot realize pulse compression, and the coding in multiple cycles forms a code period, it is possible to realize arteries and veins Punching press is contracted.One radar code period refers to one group of cycle being made up of multiple radar periods, in a radar code period Each radar period can adopt different phase codes vectors.

The detection mode of wind profile radar can be divided into low mode and height mode, height mode according to the scope of detection height Using phase code.The pulse radar transmistter of wind profile radar generally has the restriction of a maximum duty cycle, maximum duty cycle Typically 10% to 20%.The size of radar period, i.e., will meet the requirement of detection altitude range, meet wanting for dutycycle again Ask.Particularly height mode detection, in order to ensure the detection power of radar, the dutycycle after phase code is generally less than but is close to most Big space rate.

Existing wind profile radar improves dutycycle and mean power using phase coding technology, so as to ensure radar Height resolving power ensures the maximum probe height of radar again.Existing wind profile radar phase code typically adopts two-phase mutual-complementing code. The principle of two-phase mutual-complementing code is to find paired PSK sequence, and their length is identical, one of auto-correlation function Secondary lobe is another negative, and coding output is added, and the algebraical sum of secondary lobe will be zero.In addition on waveform, two-phase mutual-complementing code Two coding vectors require to launch on two individually transmitting pulse, separate detection, and then both are added.Transmitting pulse is by tight Adjacent subpulse composition, carries out mutual-complementing code phase-modulation to each subpulse.Mutual-complementing code under conditions of without Doppler effect, arteries and veins The distance side lobe of punching press contracting is zero.

Another kind of wind profile radar phase coding method adopts walsh code.Walsh code is a kind of orthogonal code, Walsh Code matrix samples to be formed to continuous walsh function, is orthogonal between its column vector of walsh code matrix (or row vector) 's.Encoded using Walsh code phase, be, on the same subpulse position of N number of radar period in radar code period, to use The vector of one N-dimensional walsh code matrix carries out phase code.

The orthogonal code phase code of this multicycle, make use of the orthogonality of coding vector, in the bar without Doppler effect Under part, the distance side lobe of pulse compression is zero as mutual-complementing code.In the case where Doppler effect is considered, mutual-complementing code and Wal Though the pulse compression distance side lobe of assorted code is not zero but very little, wind profile radar can be applied to.

The deficiencies in the prior art are：

(1) two-phase mutual-complementing code, pulse compression subpulse number are the exponential of the truth of a matter 2, not enough facilitate in design, limit arteries and veins The selection flexibility of punching press contracting subpulse number.

(2) walsh code, it is desirable to exponential of the radar period number in radar code period for the truth of a matter 2, similarly in design On not enough facilitate, limit signal transacting time domain accumulate number selection flexibility.

(3) scarce capacity of two-phase mutual-complementing code and walsh code antagonism radio point frequency interference.

The transmitting pulse maximum duty cycle Duty_cycle of wind profile radar, radar period T_r, subpulse width τ, footpath speed Measurement range V_RmaxWith operation wavelength λ, the FFT points Ns of speed FFT spectrum analysis_FFT, these index parameters are by according to radar Detection performance technical requirements are designed.The inventive method on this basis, provides a kind of Wind outline thunder based on Fei Lanke codes Up to phase coding method and circuit.

This wind profile radar phase coding method and circuit based on Fei Lanke codes disclosed by the invention, in circuit structure Aspect does not have essential distinction with prior art, and the program for solidifying in its circuit or downloading is completed according to the method for the present invention 's.This wind profile radar phase code circuit based on Fei Lanke codes disclosed by the invention, generally falls into radar frequency synthesis circuit A part, belong to the comprehensive Waveform generating circuit part of frequency.

The content of the invention

The present invention is directed to the deficiencies in the prior art, discloses a kind of wind profile radar phase code side based on Fei Lanke codes Method and circuit, make the method for the present invention and circuit possess compared with prior art and preferably resist radio point frequency interference signal Ability, solution two-phase mutual-complementing code subpulse number flexibly can not be selected, radar period number of the walsh code in radar code period The problem that flexibly can not be selected, it is hereby achieved that widely applying.

Fei Lanke code encoder matrixs are：

Realize the inventive method and solve the not enough technical scheme of prior art be：

A kind of wind profile radar phase coding method based on Fei Lanke codes, carries out multiple code periods and sends out with encoder matrix The phase code of pulse signal is penetrated, is comprised the steps：

Step 1, calculation code subpulse number M.

According to transmitting pulse maximum duty cycle Duty_cycle, radar period T_rAnd subpulse width τ calculates each Subpulse number M in radar period.

Transmitting pulse duty factor Duty_cycle is exomonental effective width and the ratio of radar period, i.e. Duty_ Cycle=M τ/T_r, have

M=uint [Duty_cycle T_r/ τ] uint [] represent take signless integer.

Step 2, calculates time domain accumulation number N_c。

According to operation wavelength λ, footpath speed measurement range V_RmaxWith radar period T_rCalculate time domain accumulation number N_c。

Footpath speed measurement range V_RmaxDetermined by Doppler frequency range be 2V_Rmax/λ.According to sampling thheorem, sample rate should For 2 times of maximum doppler frequency, i.e., sample rate should be 4V_Rmax/ λ, corresponding sampling time are λ/(4V_Rmax).Signal transacting speed The sampling time of degree FFT is T_rN_c, therefore have T_rN_c=λ/(4V_Rmax), so

N_c=uint [λ/(4V_RmaxT_r)] uint [] represent take signless integer.

Step 3, selects code period number N.

According to coding subpulse number M and signal transacting time domain accumulation number N_cSelect code period number N, make N meet M≤N≤ N_c。

Step 4, adjustment time domain accumulation number N_cWith code period number N.

Adjustment time domain accumulation number N_cWith code period number N, N is made_cN_FFTCan be evenly divisible by N, N_FFTAfter being the accumulation of signal transacting time domain The FFT points of FFT spectrum analysis.

Step 5, forms encoder matrix F '_N×M。

Select the Fei Lanke code matrix Fs of N-dimensional degree_N×N, in F_N×NIn select M column vector, in any order combination form N × M ties up encoder matrix F '_N×M。

Step 6：With encoder matrix F '_N×MCarry out the exomonental phase code of code period.

With encoder matrix F '_N×MCarry out N_cN_FFTThe exomonental phase code of/N number of code period, encoder matrix F '_N×M N number of row vector phase code, encoder matrix F ' are carried out to the transmitting pulse of the N number of radar period in code period respectively_N×MOften M element in individual row vector carries out phase code to M subpulse in respective cycle respectively.

Code period in time one by one, with encoder matrix F '_N×MCirculation one by one completes multiple codings The phase code in cycle, completes N altogether_cN_FFTThe phase code of/N number of code period.

The inventive method, the signal transacting of wind profile radar are processed using time domain accumulation, after time domain accumulation enter scanning frequency Degree FFT spectrum analysis.This method can show to simple, intuitive to accumulate in this period in time domain, what Doppler effect caused Radar return phase place change less, approximately equal, carry out phase code such that it is able to the multiple cycles within the time domain integration time With realize pulse compression.N_cN_FFTCan be evenly divisible by N, to ensure to form the code period of integer number, so as to realize multicycle phase place Coding.

The beneficial effect of the inventive method is：Fei Lanke code matrix Fs_N×NDimension N meet M≤N≤N_cAnd N_cN_FFTCan be by N Divide exactly, encoder matrix F_N×NDimension N be the integer for meeting above-mentioned requirements, and F_N×NDimension N can take less value, so as to Time domain is allowed to accumulate number N_cLess number can be taken, is signal transacting coherent time N_cN_FFTT_rAdjustment bring convenience.

And the dimension N of the encoder matrix of Walsh code must be the exponential that the truth of a matter is 2, now N_cN_FFTNecessarily can be evenly divisible by N (because of N_FFTIt is exponential that the truth of a matter is 2, and General N_FFT＞＞ N), meet M≤N≤N_cWhen, N_cThe value less than N can not be taken, adjustment is made N_cN_FFTNot enough facilitate, so that signal transacting coherent time N_cN_FFTT_rAdjustment also not enough facilitate.

Due to the signal transacting coherent time in the detection of wind profile radar sometimes for being adjusted according to weather condition, Therefore time domain accumulation number N is adjusted flexibly_cThe detection performance of wind profile radar can be improved.

In addition in some cases, wind profile radar requires N in the design of signal transacting_cValue is less, limits N, Usage charges orchid gram code matrix F is allowed now_N×N, and Walsh code cannot be applied.

It should be noted that time domain can be replaced to accumulate with the FFT of big points, N is such as carried out_cN_FFTThe FFT spectrum of points point Analysis.Now, the frequency spectrum data more than wind profile radar footpath speed measurement range is nonsensical, should be abandoned, Wind outline Frequency spectrum data in the speed measurement range of radar footpath is effective data.Time domain accumulation number now is surveyed as wind profile radar footpath speed One important parameter of amount scope, it has together decided on footpath speed measurement range with radar period.Although signal transacting can not enter The actual time domain accumulation of row, but remain effective according to time domain accumulation parameter designing coding method out.Therefore this Bright method, is described according to accumulating with time domain.

Wind profile radar phase coding method of the present invention, described transmitting pulse include M subpulse, its transmitting Waveform is burst waveforms, the time interval with a determination between subpulse.

Transmitting pulse signal, can be normal pulsed waveform, and subpulse is continuous, or train of pulse in time Waveform, the time interval with a determination between subpulse.Fei Lanke codes and Walsh code all can be to adopt burst waveforms Coding.

The requirement of docking receipts machine bandwidth is mainly reduction of using the beneficial effect of burst waveforms, reaches pulse compression ratio To calculated value, and the bandwidth of transmission signal can be also reduced, make emission spectrum readily satisfy the requirement of radio control.

Using burst waveforms for mutual-complementing code, short-distance blind section, therefore mutual-complementing code are increased typically using common Impulse waveform.Fei Lanke codes and Walsh code are all orthogonal codes, as short-distance blind section can be reduced, therefore can be with practical application Burst waveforms.

Wind profile radar phase coding method described in the inventive method, step 3, when selecting code period number N, further Be improved to, make N meet LM≤N≤N_c/ k, L are positive integers, and k is the arithmetic number for meeting k >=1, and k, L meet the constraint kL >= 4, step 5 forms encoder matrix F '_N×MWhen, it is further modified to, in Fei Lanke code matrix Fs_N×NAccording to interval L and arbitrarily Order selects M column vector, forms N × M dimension encoder matrix F '_N×M。

Its advantage is described as follows：

(1) Fei Lanke codes matrix F_N×NIn a column vector, correspondence code period in N number of radar period a sub- arteries and veins Rush position.A radar period in the N number of radar period of an element correspondence in column vector.Multicycle to a subpulse Change of the phase code equivalent to carrier frequency.Fei Lanke code matrix Fs_N×NIn each column vector one carrier frequency frequency of correspondence, adjacent column The frequency spacing of vector is (1/T_r)/N。

(2) N meets LM≤N≤N_c/ k, and column vector is selected according to frequency interval L, so increase frequency spacing.Now The frequency spacing of the column vector picked out is (1/T_r)L/N.Due to N≤N_c/ k, frequency spacing are more than or equal to (1/T_r)kL/N_c, kL >=4, so frequency spacing minimum of a value is 4/ (T_rN_c)。

(3) this time frequency point spacing minimum of a value is to survey 1/ (T of Doppler frequency maximum_rN_c) 4 times, test the speed in the range of Doppler frequency side lobe performance of will not adjusting the distance has big impact.When in view of signal transacting medium velocity FFT using weighting, point Analysis bandwidth is usually no more than 2 times of original analysis bandwidth, therefore signal transacting using side lobe performance of will not also adjusting the distance during weighting There is big impact.KL >=4, increase frequency spacing, so that the distance side lobe of phase code reduces.Phase code sidelobe performance It is the key characteristic of phase code, the distance side lobe for reducing phase code has great importance for wind profile radar.

Phase coding method described in the inventive method, step 3, when selecting code period number N, are further modified to, N is made to select as (M+1)≤N≤N_cUnder the conditions of N values.

Phase coding method described in the inventive method, step 3, when selecting code period number N, are further modified to, N is made to select as L (M+1)≤N≤N_cN values under the conditions of/k, and k, L meet the constraint kL >=4, step 5 form encoder matrix F′_N×MWhen, it is further modified to, in Fei Lanke code matrix Fs_N×NAccording to interval L and random order select M column vector, shape Encoder matrix F ' is tieed up into N × M_N×M。

Above-mentioned this 2 are further improved, and the selection of N and its implementation, principle and beneficial effect are described as follows：

(1) according to M+1 subpulse selecting the dimension N of encoder matrix, in Fei Lanke code matrix Fs_N×NIn in any order Select M column vector or M column vector is selected according to interval L and random order, form the encoder matrix F ' that N × M reforms_N×M, At this moment the selection of column vector will not choose all of common M+1 column vector.Encoder matrix is designed i.e. according to M+1 subpulse Dimension N, the frequency of have more a subpulse is used to resisting radio point frequency and disturbs.

(2) therefore when there is radio point frequency disturb near encoder matrix F '_N×MDuring frequency corresponding to certain column vector, This column vector is picked out into replacing, then now uses F '_N×MCoding realizes pulse compression ability and can suppress this wireless again Electricity point frequency is disturbed.Choose and changed with the immediate column vector of interference signal frequency frequency, can be regarded as to interference signal Frequency is hidden and is resisted.

(3) due to Fei Lanke code matrix Fs '_N×MIn each column vector one frequency of correspondence, therefore hide and resist wirelessly Electricity point frequency is disturbed easily to be realized, and the equivalent corresponding frequency of each column vector of Walsh code is not a frequency, but has frequency spectrum Distribution, the method by changing column vector can not be hidden completely, it is impossible to resist.

The technical scheme realized circuit of the present invention and solve prior art deficiency is：

A kind of wind profile radar phase code circuit based on Fei Lanke codes, carries out multiple code periods and sends out with encoder matrix The phase code of pulse signal is penetrated, its circuit composition includes：Storage circuit 1, sequence circuit 2, DDS circuit 3, amplitude modulation circuit 4th, frequency changer circuit 5 and control computer 6.

Described phase code circuit its control computer 6 performs following steps：

Step 1, calculation code subpulse number M.

According to transmitting pulse maximum duty cycle Duty_cycle, radar period T_rAnd subpulse width τ calculates coding Subpulse number M.

M=uint [Duty_cycle T_r/ τ] uint [] represent take signless integer.

Step 2, calculates time domain accumulation number N_c。

According to operation wavelength λ, footpath speed measurement range V_RmaxWith radar period T_rCalculate signal transacting time domain accumulation number N_c。

N_c=uint [λ/(4V_RmaxT_r)] uint [] represent take signless integer.

Step 3, selects code period number N.

According to coding subpulse number M and time domain accumulation number N_cCode period number N is selected, makes N meet LM≤N≤N_c/ k, L are Positive integer, k is the arithmetic number for meeting k >=1, and k, L meet the constraint kL >=4.

Step 5, forms encoder matrix F '_N×M。

Select the Fei Lanke code matrix Fs of N-dimensional degree_N×N, in F_N×NAccording to interval L select M column vector, in any order Combination forms N × M dimension encoder matrix F '_N×M。

Step 6, downloads the time sequence parameter of sequence circuit 2.

Time sequence parameter is downloaded to sequence circuit 2 by control signal 105, these parameters include radar period T_r, subpulse Number M, subpulse spacing τ_r, subpulse width τ, code period number N, time domain accumulation number N_cPoints N is analyzed with speed FFT spectrum_FFT。

Step 7, downloads encoder matrix F '_N×MAnd start sequence circuit 2.

By control signal 103 by encoder matrix F '_N×MMatrix downloads to storage circuit 1, and is opened by control signal 105 Dynamic sequence circuit 2.

Storage circuit 1, which is used for the baseband signal data for prestoring a radar period and the encoder matrix downloaded F′_N×M, in the presence of the control signal 106 that clock signal 102 and sequence circuit 2 are given, N is sent to DDS circuit 3_cN_FFT/N The baseband signal 107 of individual code period and N_cN_FFTThe encoded signal 108 of/N number of code period.

The baseband signal data of the radar period for prestoring is,l∈[0,T_r/t_s- 1], T_rFor radar period, f_bFor the frequency of baseband signal, t_sFor the sampling time of baseband signal, l is sample sequence number.

Baseband signal 107 in the coherent time of the output of storage circuit 1, its expression formula is

Encoded signal 108 in the coherent time of the output of storage circuit 1, its expression formula is

In formula, Q=N_cN_FFT/N

v₁T () is following impulse function

f′_n.,mIt is F '_N×MIn an element.Radar period T might as well be required in design_rWith subpulse spacing τ_rIt is base band letter Number sampling time t_sIntegral multiple.

Sequence circuit 2, which is used in the presence of the control signal 105 that clock signal 104 and control computer 6 are given, Output control signal 106 is controlled to storage circuit 1.Time sequence parameter of the sequence circuit 2 according to download, control memory 1 Address and data/address bus, make storage circuit 1 produce N_cN_FFTBaseband signal 107 and the encoded signal 108 of/N number of code period, and Produce N_cN_FFTThe impulse amplitude control signal 109 of/N number of code period, is sent to amplitude modulation circuit 4.

The impulse amplitude control signal 109 in the coherent time that sequence circuit 2 is produced, its expression formula is

v₂T () is following impulse function

τ be subpulse width, τ≤τ_r, subpulse width is less than or equal to subpulse spacing.

DDS circuit 3, which is used in the presence of clock signal 101, completes the number of baseband signal 107 and encoded signal 108 According to synthesis and digital-to-analogue conversion, the coding intermediate-freuqncy signal 110 of simulation is exported.

DDS circuit 3 includes two-way digital multiplier, adder, a DAC digital to analog converter and an analog filtering Device.Clock signal 101 is used for the clock of DAC digital to analog converters.Storage circuit 1 exports baseband signal 107 and encoded signal 108 is sent To DDS circuit 3,3 exports coding intermediate-freuqncy signal 110 of DDS circuit.Following computing is carried out in DDS circuit 3：Baseband signal u (l) Real part be multiplied with the real part of encoded signal P (l), the imaginary part of baseband signal u (l) is multiplied with the imaginary part of encoded signal P (l), so Latter two product term subtracts each other, and is as a result：

Wherein,

f′_n,mIt is encoder matrix F '_N×MAn element, arg () represents and takes the function of plural phase angle.

In DDS circuit 3, DAC digital to analog converters and analog filter carry out digital-to-analogue conversion, the analog signal of output to B (l) Intermediate-freuqncy signal 110 is encoded as, its expression formula is：

Wherein,

Amplitude modulation circuit 4, which is used in the presence of impulse amplitude control signal 109, by the coding intermediate frequency letter of simulation Numbers 110 are modulated to the coding medium-frequency pulse signal 111 simulated, and export frequency changer circuit 5.

The coding medium-frequency pulse signal 111 of output, its expression formula is

Frequency changer circuit 5 for by local oscillation signal 112 and 111 frequency conversion of coding medium-frequency pulse signal for wind profile radar transmitting Pulse signal 113.

Local oscillation signal 112 can be written asLocal oscillation signal 112 and coding medium-frequency pulse signal 111 Multiplication filtering takes and frequency or difference frequency, and through amplifying, transmitting pulse signal 113 its expression formula is：

In formula：f₀=f_L±f_b,f₀To launch pulse carrier frequency,Transmitting pulse carrier phase.A is Signal amplitude.

With the development of the hardware technologies such as calculating, storage, waveform generation, using Fei Lanke code matrix Fs_N×NCarry out leggy Phase code more and more easily realize.This wind profile radar phase coding method and circuit based on Fei Lanke codes, can be with Using normal pulsed or burst waveforms, select flexible with low distance side lobe, subpulse number, can be used for antagonism active dry Signal is disturbed, various wind profile radar is widely used in, with good application prospect.

Description of the drawings

Fig. 1 radar transmitted pulse schematic diagrames of the present invention

Fig. 2 radar transmitted pulse code period schematic diagrames

Fig. 3 encoder matrixs carry out the exomonental phase code schematic diagram of a code period

Fig. 4 phase-coded signals produce schematic block circuit diagram

The step of Fig. 5 the inventive method specific embodiment 1,2,3,5 flow chart

The step of Fig. 6 the inventive method specific embodiment 4,6 flow chart

The calculating of Fig. 77 control computers 6 of circuit specific embodiment of the present invention and control flow chart.

Fig. 1 illustrates exomonental waveform diagram in a radar period, depicts burst waveforms.Such as fruit arteries and veins Rush interval τ_rEqual with subpulse width τ, then subpulse is a wide normal pulsed on waveform, and now phase code is right The subpulse of the decile in wide normal pulsed carries out phase code.Within the time period shown in transmitting pulse overall width, receive Passage is closed by the transmit-receive switch of pulse wind profile radar, not gathered data.Within the time period shown in range time delay, receive logical Road is opened, the intermediate-frequency receiver gathered data of radar.

See from figure, a radar period T_rIt is interior, there is M subpulse, subpulse width is τ, and subpulse is at intervals of τ_r, Radar period T_r=τ_PulseAll+τ_Rmax, wherein exomonental overall width τ_PulseAll=τ_r(M-1)+τ, range time delay τ_Rmax= 2R_max/ C, R_maxIt is that, apart from range, C represents the light velocity.The cycle T of wind profile radar_rDepend primarily on τ_Rmax, τ_Rmax＞＞ τ_PulseAll, it is contemplated that reduce the impact apart from image, the cycle T of general radar_rIt is designed as being far longer than range time delay τ_Rmax, i.e., T_r＞＞ τ_Rmax。

Fig. 2 illustrates transmitting pulse code cycle schematic diagram, code period NT_rIn time, there is N number of radar period, Each radar period T is illustrated in Fig. 2_rInterior transmitting pulse overall width τ_PulseAllThis time period.Coding week is illustrated in Fig. 2 Phase in time one by one, a total of N_cN_FFTIndividual radar period, N_cN_FFT/ N is integer, and the number of code period is N_cN_FFT/ N, is integer.

Fig. 3 illustrates the exomonental phase code schematic diagram that a code period is carried out with encoder matrix.When in Fig. 3 Countershaft is divided into N sections.Time 1, this section represented [0, T_r) first radar period time period is represented, the time 2, this section was represented [T_r, 2T_r) represent second radar period time period, time N this section representative [(N-1) T_r, NT_r) represent n-th radar period Time period.

This N number of radar period constitutes a radar code period.There is the subpulse of M transmitting in each radar period. The subpulse drawn in figure is burst waveforms, if subpulse interval is equal with subpulse width, subpulse is on waveform It is a wide normal pulsed, now phase code is that the subpulse to the decile in wide normal pulsed carries out phase code.

Illustrate in Fig. 3 carries out the encoder matrix F of phase code control to N × M subpulse in a code period ′_N×M, f '_n,mFor encoder matrix F '_N×MIn element.

F′_N×MIn first row vector (f '_1,1,f′_1,2,…,f′_1,M) first radar period in code period is entered Line phase is encoded, f '_1,1First subpulse of correspondence, f '_1,2Second subpulse of correspondence, f '_1,MCorrespondence m-th subpulse.F′_N×M In second row vector (f '_2,1,f′_2,2,…,f′_2,M) phase code is carried out to second radar period in code period, f′_2,1First subpulse of correspondence, f '_2,2Second subpulse of correspondence, f '_2,MCorrespondence m-th subpulse.F′_N×MIn n-th row Vector (f '_N,1,f′_N,2,…,f′_N,M) phase code, f ' are carried out to the n-th radar period in code period_N,1Correspondence first Subpulse, f '_N,2Second subpulse of correspondence, f '_N,MCorrespondence m-th subpulse.

F′_N×MIn first column vector (f '_1,1,f′_2,1,…,f′_N,1)^TThe of each radar period in correspondence code period One subpulse, F '_N×MIn second column vector (f '_1,2,f′_2,2,…,f′_N,2)^TEach radar period in correspondence code period Second subpulse, F '_N×MIn m-th column vector (f '_1,M,f′_2,M,…,f′_N,M)^TEach radar period in correspondence code period M-th subpulse.

Fig. 4 is that phase-coded signal produces schematic block circuit diagram, and its composition includes：Storage circuit 1, sequence circuit 2, DDS Circuit 3, amplitude modulation circuit 4, frequency changer circuit 5, control computer 6.Input and output and connection in Fig. 4 include：

Clock signal 101：The clock signal of DDS circuit 3

Clock signal 102：The clock signal of storage circuit 1

Control signal 103：Control computer 6 is supplied to the data of storage circuit 1 to download and control signal

Clock signal 104：The clock signal of sequence circuit 2

Control signal 105：Control computer 6 is supplied to the data of sequence circuit 2 to download and control signal

Control signal 106：Control signal of the sequence circuit 2 to storage circuit 1

Baseband signal 107：Baseband signal of the output of storage circuit 1 to DDS circuit 3

Encoded signal 108：Encoded signal of the output of storage circuit 1 to DDS circuit 3

Control signal 109：Control signal of the sequence circuit 2 to amplitude modulation circuit 4

Coding intermediate-freuqncy signal 110：The baseband coding intermediate-freuqncy signal of the output of DDS circuit 3

Coding medium-frequency pulse signal 111：The baseband coding medium-frequency pulse signal of the output of amplitude modulation circuit 4

Local oscillation signal 112：The local oscillator input signals of the frequency changer circuit 5 of the comprehensive offer of radar frequency

Transmitting pulse signal 113：The output signal of up-converter circuit 5.

The step of Fig. 5 is the inventive method specific embodiment 1,2,3,5 flow chart.

Step 201：Calculation code subpulse number M

Step 202：Calculate time domain accumulation number N_c

Step 203：Select code period number N

Step 204：Adjustment time domain accumulation number N_cWith code period number N

Step 205：Form encoder matrix F '_N×M

Step 206：With encoder matrix F '_N×MThe phase code of multiple code periods is carried out, N is completed altogether_cN_FFT/ N number of coding The phase code in cycle.

The step of Fig. 6 is the inventive method specific embodiment 4,6 flow chart.

Step 301：Calculation code subpulse number M

Step 302：Calculate time domain accumulation number N_c

Step 303：Select code period number N

Step 304：Adjustment time domain accumulation number N_cWith code period number N

Step 305：Form encoder matrix F '_N×M

Step 306：With encoder matrix F '_N×MThe phase code of multiple code periods is carried out, N is completed altogether_cN_FFT/ N number of coding The phase code in cycle.

Fig. 7 is the calculating of 7 control computer 6 of circuit specific embodiment of the present invention and control flow chart.Illustrate in Fig. 7 into The step of row is once calculated and is controlled.

Step 401：Calculation code subpulse number M

Step 402：Calculate time domain accumulation number N_c

Step 403：Select code period number N

Step 404：Adjustment time domain accumulation number N_cWith code period number N

Step 405：Form encoder matrix F '_N×M

Step 406：Download the time sequence parameter of sequence circuit 2

Step 407：Download encoder matrix F '_N×MTo storage circuit 1, and start sequence circuit 2.

In accompanying drawing, the list of parts representated by each label is as follows：

1st, storage circuit, 2, sequence circuit, 3, DDS circuit, 4, amplitude modulation circuit, 5, frequency changer circuit.

Specific embodiment

Hereinafter the specific embodiment of the method for the present invention and circuit is illustrated, example be used for explain and Absolutely prove technical scheme and applicability.

Embodiment 1：

A kind of packaged type L-band boundary layer wind-profile radar, operating frequency f₀=1320MHz, maximum probe height R_max =3km, measuring wind speed scope are 0～60m/s (maximum wind velocity V_max=60m/s), height mode range resolution is D=120m, high Pattern adopts phase code, launches pulse maximum duty cycle Duty_cycle=10%, oblique wave beam tilt angle α=14.8 °.

Range time delay τ_RmaxAccording to maximum probe height R_maxCalculate, τ_Rmax=2R_max/ C=20 μ S, C are the light velocity, if The radar period T of meter wind profile radar_r=50 μ S, can meet the needs apart from range, and T_r＞＞ τ_Rmax, launch pulse total Width τ_PulseAllPermissible value is larger, can adopt burst waveforms, 2 times for subpulse width of subpulse spacing.Referring to Fig. 1 and its Illustrate, Fig. 1 illustrates transmitting pulse overall width τ in a radar period_PulseAll, range time delay τ_RmaxWith radar period T_rPass System.

The signal transacting FFT points Ns of wind profile radar_FFTUsually 512.Operation wavelength λ is according to operating frequency f₀Calculate Come, λ=C/f₀=0.2273m.Subpulse width τ converts out according to range resolution D, τ=2D/C=0.8 μ S.Maximum diameter Fast V_RmaxAccording to maximum wind velocity V_maxCalculate with oblique wave beam tilt angle α, V_Rmax=V_max sin(α),V_Rmax=15.4m/S.

For the present embodiment, being embodied as of the inventive method technical scheme is described as follows：

A kind of wind profile radar phase coding method based on Fei Lanke codes, carries out multiple code periods and sends out with encoder matrix The phase code of pulse signal is penetrated, is comprised the following steps：

Step 1, calculation code subpulse number M.

M=uint [Duty_cycle T_r/τ]

The present embodiment, referring to the step 201 in Fig. 5, Duty_cycle=10%, T_r=50 μ S, τ=0.8 μ S, Ke Yiji Subpulse number M=6 is calculated, now actual duty cycle is 9.6% less than 10%.

Step 2, calculates time domain accumulation number N_c。

N_c=uint [λ/(4V_RmaxT_r)]

The present embodiment, referring to the step 202 in Fig. 5, λ=0.2273m, V_Rmax=15.3m/S, T_r=50 μ S, can calculate Go out time domain accumulation number N_c, calculate N_c=74.

Step 3, selects code period number N.

According to coding subpulse number M and signal transacting time domain accumulation number N_cSelect code period number N, make N meet M≤N≤ N_c.N is further selected, makes N meet LM≤N≤N_c/ k, L are positive integers, and k is the arithmetic number for meeting k >=1, and k, L meet Constraint kL >=4.

For this example, referring to the step 203 in Fig. 5,6≤N≤74.N=24 is further selected, there is k=3, L=4, this When N meet LM≤N≤N_c/ k, and meet the constraint kL >=4.

Adjustment time domain accumulation number N_cWith code period number N, N is made_cN_FFTCan be evenly divisible by N.For this example, referring to the step in Fig. 5 Rapid 204, by N_c72, N=24 is adjusted to without adjustment, N by 74_cAdjustment amount very little, the impact to the coherent time is very small, right Detection performance without impact, N after adjustment_cN_FFT/ N=1536 is integer.

Step 5, forms encoder matrix F '_N×M。

Select the Fei Lanke code matrix Fs of N-dimensional degree_N×N, in F_N×NIn select M column vector, in any order combination form N × M ties up encoder matrix F '_N×M.Further it is to select column vector according to interval L when M column vector is selected, the row picked out Vector can form the encoder matrix F ' of N × M reforms in any order_N×M。

For this example, referring to the step 205 in Fig. 5, L=4, N=24, then F_24×24Include 24 column vectors.According to 6 column vectors are selected every L=4 orders, obtain 6 Column vector groups into 24 × 6 dimension Frank encoder matrix F '_24×6For：

C′_n,m=4nm n=0,1,2 ..., 23 m=0,1,2,3,4,5

For this example, referring to the step 206 in Fig. 5, with above-mentioned encoder matrix F '_24×6, carry out N_cN_FFT/ N=1536 volume The exomonental phase code in code cycle.

Referring to Fig. 2 and its explanation, Fig. 2 illustrates a code period and includes N number of radar period, and code period is in the time On one by one.

Encoder matrix F '_24×6Transmitting pulse of 24 row vectors respectively to 24 radar periods in code period carry out Phase code, encoder matrix F '_24×66 elements in each row vector carry out phase to 6 subpulses in respective cycle respectively Position coding.Referring to Fig. 3 and its explanation, Fig. 3 illustrates encoder matrix F '_N×MElement f '_n,mWith radar period sequence number n and subpulse Relation between sequence number m, radar period sequence number n here refer to the sequence number in a radar code period.

Embodiment 2：

A kind of fixed L-band boundary layer wind-profile radar, operating frequency f₀=1320MHz, maximum probe height R_max= 6km, measuring wind speed scope are 0～60m/s (maximum wind velocity V_max=60m/s), height mode range resolution is D=120m, Gao Mo Formula adopts phase code, launches pulse maximum duty cycle Duty_cycle=10%, oblique wave beam tilt angle α=14.8 °.

Range time delay τ_RmaxAccording to maximum probe height R_maxCalculate, τ_Rmax=2R_max/ C=40 μ S, C are the light velocity, if The radar period T of meter wind profile radar_r=80 μ S, can meet the needs apart from range time delay, T_r＞＞ τ_Rmax, launch pulse Overall width τ_PulseAllHigher value is allowed, burst waveforms, 2 times for subpulse width of subpulse spacing can be adopted.Referring to Fig. 1 And its illustrate, Fig. 1 illustrates transmitting pulse overall width τ in a radar period_PulseAll, range time delay τ_RmaxWith radar period T_r Relation.The signal transacting FFT points Ns of wind profile radar_FFTUsually 512.Operation wavelength λ is calculated according to operating frequency f Come, λ=C/f=0.2273m.Subpulse width τ converts out according to range resolution D, τ=2D/C=0.8 μ S.Maximum diameter speed V_RmaxAccording to maximum wind velocity V_maxCalculate with oblique wave beam tilt angle α, V_Rmax=V_max sin(α),V_Rmax=15.3m/S.

Step 1, calculation code subpulse number M.

M=uint [Duty_cycle T_r/τ]

The present embodiment, referring to the step 201 in Fig. 5, Duty_cycle=10%, T_r=80 μ S, τ=0.8 μ S, Ke Yiji Subpulse number 10 is calculated, now dutycycle is 10% less than 10%.

Step 2, calculates time domain accumulation number N_c。

N_c=uint [λ/(4V_RmaxT_r)]

The present embodiment, referring to the step 202 in Fig. 5, λ=0.2273m, V_Rmax=15.3m/S, T_r=80 μ S, can calculate Go out time domain accumulation number N_c, calculate N_c=46.

Step 3, selects code period number N.

For this example, referring to the step 203 in Fig. 5,10≤N≤46.N=10 is further selected, there is k=4.6, L= 1, now N meet LM≤N≤N_c/ k, and meet the constraint kL >=4.

For this example, referring to the step 204 in Fig. 5, time domain accumulation number N_cConstant, the N that is adjusted to 45, N=10 by 46_cTune Whole amount very little, the impact to the coherent time are very small, on detection performance without impact, N after adjustment_cN_FFT/ N=2304 is integer.

Step 5, forms encoder matrix F '_N×M。

For this example, referring to the step 205 in Fig. 5, L=1, N=10, then F_10×10Include 10 column vectors.According to suitable Sequence selects 10 column vectors, obtain 10 Column vector groups into 10 × 10 dimension Frank encoder matrix F '_10×10For：

C′_n,m=nm n=0,1,2 ..., 9 m=0,1,2 ..., 9

For this example, referring to the step 206 in Fig. 5, with above-mentioned encoder matrix F '_10×10, carry out N_cN_FFT/ N=2304 volume The exomonental phase code in code cycle.

Encoder matrix F '_10×10Transmitting pulse of 10 row vectors respectively to 10 radar periods in code period enter Line phase is encoded, encoder matrix F '_10×1010 elements in each row vector enter to 10 subpulses in respective cycle respectively Line phase is encoded, referring to Fig. 3 and its explanation.Fig. 3 illustrates encoder matrix F '_N×MElement f '_n,mWith radar period sequence number n and son Relation between pulse sequence number m, radar period sequence number n here refer to the sequence number in a radar code period.

Embodiment 3：

A kind of fixed L-band boundary layer wind-profile radar, operating frequency f₀=1320MHz, maximum probe height R_max= 10km, measuring wind speed scope are 0-80m/s (maximum wind velocity V_max=80m/s), height mode range resolution is D=240m, Gao Mo Formula adopts phase code, launches pulse maximum duty cycle Duty_cycle=10%, oblique wave beam tilt angle α=14.8 °.

Range time delay τ_RmaxAccording to maximum probe height R_maxCalculate, τ_Rmax=2R_max/ C=66.7 μ S, C are the light velocity, The radar period T of design wind profile radar_r=100 μ S, can meet the needs apart from range, T_r＞＞ τ_Rmax, launch pulse total Width τ_PulseAllMaximum is 33.3 μ S, launches pulse and can adopt impulse waveform.Referring to Fig. 1 and its explanation, Fig. 1 illustrates one Transmitting pulse overall width τ in radar period_PulseAll, range time delay τ_RmaxWith radar period T_rRelation.The letter of wind profile radar Number process FFT points Ns_FFTUsually 512.Operation wavelength λ is calculated according to operating frequency f, λ=C/f=0.2273m.Sub- arteries and veins Rush width τ to convert out according to range resolution D, τ=2D/C=1.6 μ S.Maximum diameter speed V_RmaxAccording to maximum wind velocity V_maxWith it is oblique Beam tilt angles α is calculated, V_Rmax=V_max sin(α),V_Rmax=20.4m/S.

Step 1, calculation code subpulse number M.

M=uint [Duty_cycle T_r/τ]

The present embodiment, referring to the step 201 in Fig. 5, Duty_cycle=10%, T_r=100 μ S, τ=1.6 μ S, can be with Calculate subpulse number, M=6, now dutycycle is 9.6% to be less than 10%.

Step 2, calculates time domain accumulation number N_c。

N_c=uint [λ/(4V_RmaxT_r)]

The present embodiment, referring to the step 202 in Fig. 5, λ=0.2273m, V_Rmax=20.4m/S, T_r=100 μ S, Ke Yiji Calculate time domain accumulation number N_c, calculate N_c=28.

Step 3, selects code period number N.

According to coding subpulse number M and time domain accumulation number N_cCode period number N is selected, makes N meet M≤N≤N_c.Further Ground selects N, makes N meet LM≤N≤N_c/ k, L are positive integers, and k is the arithmetic number for meeting k >=1, and k, L meet the constraint kL >= 4。

For this example, referring to the step 203 in Fig. 5,6≤N≤28 further select N=6, there is k=4.67, L=1, Now meet LM≤N≤N_c/ k, and meet the constraint kL >=4.

For this example, referring to the step 204 in Fig. 5, time domain accumulation number N_c27, N=6 is adjusted to by 28 constant, to coherent The impact of time is very small, on detection performance without impact, N after adjustment_cN_FFT/ N=2304 is integer.

Step 5, forms encoder matrix F '_N×M。

For this example, referring to the step 205 in Fig. 5, L=1, N=6, then F_6×6Include 6 column vectors.Choose in order Choose 6 column vectors, obtain 6 Column vector groups into 6 × 6 dimension Frank encoder matrix F '_6×6For：

C′_n,m=nm n=0,1,2 ..., 5 m=0,1,2 ..., 5

For this example, referring to the step 206 in Fig. 5, with above-mentioned encoder matrix F '_6×6, carry out N_cN_FFT/ N=2304 volume The exomonental phase code in code cycle.

Referring to Fig. 2 and its explanation.Fig. 2 illustrates a code period and includes N number of radar period, and code period is in the time On one by one.

Encoder matrix F '_6×6Transmitting pulse of 6 row vectors respectively to 6 radar periods in code period carry out phase Position coding, encoder matrix F '_6×66 elements in each row vector carry out phase place volume to 6 subpulses in respective cycle respectively Code, referring to Fig. 3 and its explanation.Fig. 3 illustrates encoder matrix F '_N×MElement f '_n,mWith radar period sequence number n and subpulse sequence number Relation between m, radar period sequence number n here refer to the sequence number in a radar code period.

For this example, the time domain accumulation number N of signal transacting_cThe points N of=27, FFT_FFT=512, it is also possible to do not carry out reality The time domain accumulation on border, is changed to carry out doppler frequency spectrum analysis using 27 × 512=13824 point FFT, abandons representative more than V_Rmax= The frequency spectrum data of 20.4m, is retained less than equal to V_RmaxThe frequency spectrum data of=20.4m is used as valid data.Now time domain accumulation number N_c =27 as design process in an important parameter.

Embodiment 4：

A kind of fixed pattern-band troposphere wind profiler radar, operating frequency f₀=445MHz, maximum probe height R_max= 12km, measuring wind speed scope are 0-100m/s (maximum wind velocity V_max=100m/s), height mode range resolution is D=240m, high Pattern adopts phase code, launches pulse maximum duty cycle Duty_cycle=10%, oblique wave beam tilt angle α=14.8 °.

Range time delay τ_RmaxAccording to maximum probe height R_maxCalculate, τ_Rmax=2R_max/ C=80 μ S, C are the light velocity, if The radar period T of meter wind profile radar_r=120 μ S, can meet the needs of range, T_r＞＞ τ_Rmax, launch pulse overall width τ_PulseAllPermissible value is larger, and transmitting pulse can adopt burst waveforms, 2 times for subpulse width of subpulse spacing.Referring to Fig. 1 And its illustrate, Fig. 1 illustrates transmitting pulse overall width τ in a radar period_PulseAll, range time delay τ_RmaxWith radar period T_r Relation.The signal transacting FFT points Ns of wind profile radar_FFTUsually 512.Operation wavelength λ is calculated according to operating frequency f Come, λ=C/f=0.674m.Subpulse width τ converts out according to range resolution D, τ=2D/C=1.6 μ S.Maximum diameter speed V_RmaxAccording to maximum wind velocity V_maxCalculate with oblique wave beam tilt angle α, V_Rmax=V_max sin(α),V_Rmax=25.6m/S.

Step 1, calculation code subpulse number M.

M=uint [Duty_cycle T_r/τ]

The present embodiment, referring to the step 301 in Fig. 6, Duty_cycle=10%, T_r=120 μ S, τ=1.6 μ S, can be with Calculate subpulse number, M=7, now dutycycle is 9.3% to be less than 10%.

Step 2, calculates time domain accumulation number N_c。

N_c=uint [λ/(4V_RmaxT_r)]

The present embodiment, referring to the step 302 in Fig. 6, λ=0.674m, V_Rmax=25.6m/S, T_r=120 μ S, can calculate Go out time domain accumulation number N_c, calculate N_c=54.

Step 3, selects code period number N.

According to coding subpulse number M and time domain accumulation number N_cCode period number N is selected, makes N meet M≤N≤N_c.Further Ground selects N, makes N meet L (M+1)≤N≤N_c/ k, L are positive integers, and k is the arithmetic number for meeting k >=1, and k, L meet the constraint kL≥4。

For this example, referring to the step 303 in Fig. 6,7≤N≤54 further select N=8, there is k=6.75, L=1, Now meet L (M+1)≤N≤N_c/ k, and meet the constraint kL >=4.

For this example, referring to the step 304 in Fig. 6, N_cIt is 0, N with N adjustment amounts_cN_FFT/ N=3456 is integer.

Step 5, forms encoder matrix F '_N×M。

For this example, referring to the step 305 in Fig. 6, L=1, N=8, then F_8×8Include 8 column vectors.Choose in order Choose 7 column vectors, obtain 7 Column vector groups into 8 × 7 dimension Fei Lanke encoder matrix F '_8×7For：

C′_n,m=nm n=0,1,2 ..., 7 m=0,1,2 ..., 6

For this example, referring to the step 306 in Fig. 6, with above-mentioned encoder matrix F '_8×7, carry out N_cN_FFT/ N=3456 volume The exomonental phase code in code cycle.

Encoder matrix F '_8×7Transmitting pulse of 8 row vectors respectively to 8 radar periods in code period carry out phase Position coding, encoder matrix F '_8×77 elements in each row vector carry out phase place volume to 7 subpulses in respective cycle respectively Code, referring to Fig. 3 and its explanation.Fig. 3 illustrates encoder matrix F '_N×MElement f '_n,mWith radar period sequence number n and subpulse sequence number Relation between m, radar period sequence number n here refer to the sequence number in a radar code period.

N ＞ M in this example, encoder matrix F '_8×7In non-selected matrix F_8×8Last column vector, in its corresponding frequency Disturb if there is a frequency on point, then this point frequency can be suppressed to disturb.Disturb if there is a frequency on certain frequency, then exist M=7 column vector is selected, the encoder matrix F ' of 8 × 7 dimensions is formed_8×7When, do not select a frequency and disturb corresponding column vector, so as to hide Keep away and resist this point frequency to disturb.

Embodiment 5：

A kind of fixed pattern-band alto-troposphere wind profile radar, operating frequency f₀=445MHz, maximum probe height R_max =16km, measuring wind speed scope are 0-100m/s (maximum wind velocity V_max=100m/s), height mode range resolution is D=480m, Height mode adopts phase code, launches pulse maximum duty cycle Duty_cycle=20%, oblique wave beam tilt angle α=14.8 °.

Range time delay τ_RmaxAccording to maximum probe height R_maxCalculate, τ_Rmax=2R_max/ C=106.6 μ S, C are the light velocity, The radar period T of design wind profile radar_r=160 μ S, can meet the needs of range, T_r＞＞ τ_Rmax, launch pulse overall width τ_PulseAllMaximum is 53.4 μ S, launches pulse and can adopt impulse waveform.Referring to Fig. 1 and its explanation, Fig. 1 illustrates a thunder Launch pulse overall width τ up within the cycle_PulseAll, range time delay τ_RmaxWith radar period T_rRelation.The signal of wind profile radar Process FFT points Ns_FFTUsually 512.Operation wavelength λ is calculated according to operating frequency f, λ=C/f=0.674m.Subpulse Width τ converts out according to range resolution D, τ=2D/C=3.2 μ S.Maximum diameter speed V_RmaxAccording to maximum wind velocity V_maxAnd oblique wave Beam tilt angle α is calculated, V_Rmax=V_max sin(α),V_Rmax=25.6m/S.

Step 1, calculation code subpulse number M.

M=uint [Duty_cycle T_r/τ]

The present embodiment, referring to the step 201 in Fig. 5, Duty_cycle=20%, T_r=160 μ S, τ=3.2 μ S, can be with Calculate subpulse number, M=10, now dutycycle is 20%.

Step 2, calculates time domain accumulation number N_c。

N_c=uint [λ/(4V_RmaxT_r)]

The present embodiment, referring to the step 202 in Fig. 5, λ=0.674m, V_Rmax=25.6m/S, T_r=160 μ S, can calculate Go out time domain accumulation number N_c, calculate N_c=41.

Step 3, selects code period number N.

For this example, referring to the step 203 in Fig. 5,10≤N≤41 further select N=20, there is k=2, L=2, Now meet LM≤N≤N_c/ k, and meet the constraint kL >=4.

Adjustment time domain accumulation number N_cWith code period number N, N is made_cN_FFTCan be evenly divisible by N, N_FFTAfter being the accumulation of signal transacting time domain The FFT points of FFT spectrum analysis.For this example, referring to the step 204 in Fig. 5, N_c=41 are adjusted to N_c=40, to the coherent time Impact it is very small, on detection performance without impact, the adjustment amount of N is 0, then N_cN_FFT/ N=1024 is integer.

Step 5, forms encoder matrix F '_N×M。

For this example, referring to the step 205 in Fig. 5, L=2, N=20, then F_20×20Include 20 column vectors.According to 10 column vectors are selected every L=2 orders, obtain 10 Column vector groups into 20 × 10 dimension Frank encoder matrix F '_20×10 For：

C′_n,m=2nm n=0,1,2 ..., 19 m=0,1,2 ..., 9

For this example, referring to the step 206 in Fig. 5, with above-mentioned encoder matrix F '_20×10, carry out N_cN_FFT/ N=1024 volume The exomonental phase code in code cycle.

Encoder matrix F '_20×10Transmitting pulse of 20 row vectors respectively to 20 radar periods in code period enter Line phase is encoded, encoder matrix F '_20×1010 elements in each row vector enter to 10 subpulses in respective cycle respectively Line phase is encoded, referring to Fig. 3 and its explanation.Fig. 3 illustrates encoder matrix F '_N×MElement f '_n,mWith radar period sequence number n and son Relation between pulse sequence number m, radar period sequence number n here refer to the sequence number in a radar code period.

Embodiment 6：

A kind of fixed UHF waveband alto-troposphere wind profile radar, operating frequency f₀=52MHz, maximum probe height R_max =24km, measuring wind speed scope are 0-120m/s (maximum wind velocity V_max=120m/s), height mode range resolution is D=480m, Height mode adopts phase code, launches pulse maximum duty cycle Duty_cycle=20%, oblique wave beam tilt angle α=14.8 °.

Range time delay τ_RmaxAccording to maximum probe height R_maxCalculate, τ_Rmax=2R_max/ C=160 μ S, C are the light velocity, if The radar period T of meter wind profile radar_r=240 μ S, can meet the needs apart from range, T_r＞＞ τ_Rmax, launch pulse beam overall Degree τ_PulseAllMaximum is 80 μ S, launches pulse and can adopt impulse waveform.Referring to Fig. 1 and its explanation, Fig. 1 illustrates a thunder Launch pulse overall width τ up within the cycle_PulseAll, range time delay τ_RmaxWith radar period T_rRelation.The signal of wind profile radar Process FFT points Ns_FFTUsually 512.Operation wavelength λ is calculated according to operating frequency f, λ=C/f=5.77m.Subpulse width Degree τ converts out according to range resolution D, τ=2D/C=3.2 μ S.Maximum diameter speed V_RmaxAccording to maximum wind velocity V_maxWith oblique wave beam Inclination alpha is calculated, V_Rmax=V_max sin(α),V_Rmax=30.6m/S.

Step 1, calculation code subpulse number M.

M=uint [Duty_cycle T_r/τ]

The present embodiment, referring to the step 301 in Fig. 6, Duty_cycle=20%, T_r=240 μ S, τ=3.2 μ S, can be with Calculate subpulse number, M=15, now dutycycle is 20% to be less than 20%.

Step 2, calculates time domain accumulation number N_c。

N_c=uint [λ/(4V_RmaxT_r)]

The present embodiment, referring to the step 302 in Fig. 6, λ=5.77m, V_Rmax=30.6m/S, T_r=240 μ S, can calculate Go out time domain accumulation number N_c, calculate N_c=196.

Step 3, selects code period number N.

According to coding subpulse number M and signal transacting time domain accumulation number N_cSelect code period number N, make N meet M≤N≤ N_c.N is further selected, makes N meet L (M+1)≤N≤N_c/ k, L are positive integers, and k is the arithmetic number for meeting k >=1, and k, L Meet the constraint kL >=4.

For this example, referring to the step 303 in Fig. 6,15≤N≤196 further select N=16, there is k=12.25, L =1, now meet L (M+1)≤N≤N_c/ k, and meet the constraint kL >=4.

Adjustment time domain accumulation number N_cWith code period number N, N is made_cN_FFTCan be evenly divisible by N, N_FFTAfter being the accumulation of signal transacting time domain The FFT points of FFT spectrum analysis.For this example, referring to the step 304 in Fig. 6, N_cAdjustment amount with N is 0, N_cN_FFT/ N= 6272 is integer.

Step 5, forms encoder matrix F '_N×M。

For this example, referring to the step 305 in Fig. 6, L=1, N=16, then F_16×16Include 16 column vectors.According to 15 column vectors are selected every L=1 orders, obtain 15 Column vector groups into 16 × 15 dimension Frank encoder matrix F '_16×15 For：

C′_n,m=nm n=0,1,2 ..., 15 m=0,1,2,3 ..., 14

For this example, referring to the step 306 in Fig. 6, with above-mentioned encoder matrix F '_16×15, carry out N_cN_FFT/ N=6272 volume The exomonental phase code in code cycle.

Encoder matrix F '_16×15Transmitting pulse of 16 row vectors respectively to 16 radar periods in code period enter Line phase is encoded, encoder matrix F '_16×1515 elements in each row vector enter to 15 subpulses in respective cycle respectively Line phase is encoded, referring to Fig. 3 and its explanation.Fig. 3 illustrates encoder matrix F '_N×MElement f '_n,mWith radar period sequence number n and son Relation between pulse sequence number m, radar period sequence number n here refer to the sequence number in a radar code period.

N ＞ M in this example, it is not selected to encoder matrix F '_16×15In F_16×16Last column vector, its correspondence Frequency on if there is frequency disturb, then can suppress this point frequency disturb.

Embodiment 7：

Range time delay τ_RmaxAccording to maximum probe height R_maxCalculate, τ_Rmax=2R_max/ C=66.7 μ S, C are the light velocity, The radar period T of design wind profile radar_r=100 μ S, can meet the needs apart from range, T_r＞＞ τ_Rmax, launch pulse total Width τ_PulseAllMaximum is 33.3 μ S, and transmitting pulse can be using impulse waveform, τ_r=τ.Referring to Fig. 1 and its explanation, Fig. 1 tables Transmitting pulse overall width τ in a radar period is shown_PulseAll, range time delay τ_RmaxWith radar period T_rRelation.Wind outline The signal transacting FFT points Ns of radar_FFTUsually 512.Operation wavelength λ is calculated according to operating frequency f, λ=C/f= 0.2273m.Subpulse width τ converts out according to range resolution D, τ=2D/C=1.6 μ S.τ_r=τ=1.6 μ S.Maximum diameter Fast V_RmaxAccording to maximum wind velocity V_maxCalculate with oblique wave beam tilt angle α, V_Rmax=V_max sin(α),V_Rmax=20.4m/S.

For the present embodiment, being embodied as of circuit solutions of the present invention is described as follows：

Described phase code circuit, its control computer (6) perform following steps：

Step 1, calculation code subpulse number M.

M=uint [Duty_cycle T_r/τ]

For this example, referring to the step 401 in Fig. 7, Duty_cycle=10%, T_r=100 μ S, τ=1.6 μ S, can be with Calculate subpulse number, M=6, now actual duty cycle is 9.6% to be less than 10%.

Step 2, calculates time domain accumulation number N_c。

N_c=uint [λ/(4V_RmaxT_r)]

For this example, referring to the step 402 in Fig. 7, λ=0.2273m, V_Rmax=20.4m/S, T_r=100 μ S, Ke Yiji Calculate time domain accumulation number N_c=uint [λ/(4V_RmaxT_r)], calculate N_c=28.

Step 3, selects code period number N.

For this example, referring to the step 403 in Fig. 7, select N=6, there is k=4.66, L=1, now meet LM≤N≤ N_c/ k, and meet the constraint kL >=4.

Adjustment time domain accumulation number N_cWith code period number N, N is made_cN_FFTCan be evenly divisible by N, i.e. Q=N_cN_FFT/ N be integer, N_FFT It is the FFT points of FFT spectrum analysis after time domain is accumulated.

For this example, referring to the step 404 in Fig. 7, time domain accumulation number N_c27, N=6 is adjusted to by 28 constant, to coherent The impact of time is very small, on detection performance without impact, N after adjustment_cN_FFT/ N=2304 is integer.

Step 5, forms encoder matrix F '_N×M。

For this example, referring to the step 405 in Fig. 7, L=1, N=6, then F_6×6Include 6 column vectors.Choose in order Choose 6 column vectors, obtain 6 Column vector groups into 6 × 6 dimension Fei Lanke encoder matrix F '_6×6For：

C′_n,m=nm n=0,1,2 ..., 5 m=0,1,2 ..., 5

Step 6, downloads the time sequence parameter of sequence circuit 2.

For this example, referring to the step 406 in Fig. 7, these parameters include radar period T_r, subpulse number M, between subpulse Away from τ_r, subpulse width τ, code period number N, time domain accumulation number N_cPoints N is analyzed with speed FFT spectrum_FFT。

Step 7, downloads encoder matrix F '_N×MAnd start sequence circuit 2.By control signal 103 by encoder matrix F '_N×M Matrix downloads to storage circuit 1, and starts sequence circuit 2, referring to the step 407 in Fig. 7.

The theory diagram of circuit of the present invention is referring to Fig. 4.

Storage circuit 1, which is used for the baseband signal data and encoder matrix F ' for storing a radar period_N×M, believe in clock Numbers 102 and the control signal 106 that is given of sequence circuit 2 in the presence of, send N to DDS circuit 3_cN_FFTThe base of/N number of code period Band signal 107 and N_cN_FFTThe encoded signal 108 of/N number of code period.This example, the Frequency Design of clock signal 102 is 240MHz, Inverse of the baseband signal samples time for 102 frequency of clock signal, t_s=(1/240) μ S.Base-band signal frequency is designed as, f_b= 60MHz.Baseband signal phase place might as well be designed as,

In formula, Q=N_cN_FFT/N

v₁T () is following impulse function

f′_n.,mIt is F '_N×MIn an element.Radar period T might as well be required in design_rWith subpulse spacing τ_rIt is base band letter Number sampling time t_sIntegral multiple.This example, T_r=100 μ S, τ_r=τ=1.6 μ S, t_s=(1/240) μ S, meet above-mentioned integral multiple Relation.

Sequence circuit 2, which is used in the presence of the control signal 105 that clock signal 104 and control computer 6 are given, Output control signal 106 is controlled to storage circuit 1, makes storage circuit 1 produce baseband signal 107 and encoded signal 108, and Produce N_cN_FFTThe impulse amplitude control signal 109 of/N number of code period, is sent to amplitude modulation circuit 4.

v₂T () is following impulse function

τ is subpulse width, for this example, τ=τ_r, subpulse width is equal to subpulse spacing.

Sequence circuit 2 makes memory 1 according to time sequence parameter, the address of control memory 1 and data/address bus during normal work Output baseband signal 107 and encoded signal 108.For this example, the Frequency Design of clock signal 104 is 10MHz, it is possible to achieve right The control accuracy requirement of 0.1 μ S of pulse width.

DDS circuit 3, which is used under the driving of clock signal 101, completes the number of baseband signal 107 and encoded signal 108 According to synthesis and digital-to-analogue conversion, the coding intermediate-freuqncy signal 110 of simulation is exported.

DDS circuit 3 includes two-way digital multiplier, adder, a DAC digital to analog converter and an analog filtering Device.Clock signal 101 is used for the clock of DAC digital to analog converters.Storage circuit 1 exports baseband signal 107 and encoded signal 108 is sent To DDS circuit 3,3 exports coding intermediate-freuqncy signal 110 of DDS circuit.Following computing is carried out in DDS circuit 3：Baseband signal u (l) Real part be multiplied with the real part of encoded signal P (l), the imaginary part of baseband signal u (l) is multiplied with the imaginary part of encoded signal P (l), so After subtract each other, be as a result：

Wherein,

For this example, the Frequency Design of the clock signal 101 of DDS circuit 3 is also 240MHz, the frequency values and clock signal 101 frequency is identical.

Wherein,

Amplitude modulation circuit 4, which is used in the presence of impulse amplitude control signal 109, and coding intermediate-freuqncy signal 110 is adjusted It is made as encoding medium-frequency pulse signal 111, and exports frequency changer circuit 5.

In formula：f₀=f_L±f_b,f₀To launch pulse carrier frequency,Transmitting pulse carrier phase.A is Signal amplitude.For this example, frequency f of local oscillation signal 112_L=1260MHz, Q=N_cN_FFT/ N=2304, N=6, M=6,

T_r=100 μ S, τ_r=1.6 μ S, τ=1.6 μ S, f₀=f_L+f_b=1320MHz,N_c=27, N_FFT=512, t ∈ [0, N_cN_FFTT_r), N_cN_FFTT_r=1.3824S.

Define relative time t_q,n,m=t-qNT_r-nT_r-mτ_r, then t=t_q,n,m+qNT_r+nT_r+mτ_r, relative time t_q,n,mTable Show and go to gather the waveform of (description) each subpulse for time zero according to the initial time of each subpulse.

The expression formula of t is substituted into into above formula carrier frequency part, and due to 2 π f₀(qNT_r+nT_r+mτ_rThe π l of)=2, l=qN (f₀T_r)+n (f₀T_r)+m(f₀τ_r), f might as well be required in design₀T_rAnd f₀τ_rInteger is, then l is integer.Exomonental each subpulse, It is rewritable to be：

The present embodiment, the phase code of subpulseValue list is as follows：

Example provided above is only presently preferred embodiments of the present invention, not to limit the present invention.The method of the present invention and Circuit is used for wind profile radar frequency synthesis circuit waveform generating section, provides a kind of phase based on Fei Lanke codes for wind profile radar Position coding techniques, using new pattern, it is indicated that the pass between the time domain accumulation number that encoder matrix dimension and signal transacting are related to System, it is indicated that to obtain the restriction relation required for good distance side lobe performance, illustrate that one kind realizes circuit, list many Individual embodiment, has absolutely proved that the inventive method and circuit, in wind profile radar field, can apply to all size model Wind profile radar, with comparing wide applicability.

Claims

1. a kind of wind profile radar phase coding method based on Fei Lanke codes, carries out multiple code period transmittings with encoder matrix The phase code of pulse signal, it is characterised in that comprise the steps：

Step 1, calculation code subpulse number M:According to transmitting pulse maximum duty cycle Duty_cycle, radar period T_rAnd son Pulse width τ calculates coding subpulse number M；

Step 2, calculates time domain accumulation number N_c:According to operation wavelength λ, footpath speed measurement range V_RmaxWith radar period T_rWhen calculating Domain accumulates number N_c；

Step 3, selects code period number N:According to coding subpulse number M and time domain accumulation number N_cCode period number N is selected, makes N full Sufficient M≤N≤N_c；

Step 4, adjustment time domain accumulation number N_cWith code period number N:Adjustment time domain accumulation number N_cWith code period number N, N is made_cN_FFT Can be evenly divisible by N, wherein N_FFTIt is the FFT points that FFT spectrum analysis is carried out after time domain is accumulated；

Step 5, forms encoder matrix F '_N×M:Select the Fei Lanke code matrix Fs of N-dimensional degree_N×N, in Fei Lanke code matrix Fs_N×NIn choose M column vector is selected, combination in any order forms the encoder matrix F ' of N × M dimensions_N×M；

Step 6, with encoder matrix F '_N×MCarry out the exomonental phase code of code period:With encoder matrix F '_N×MCarry out N_cN_FFTThe exomonental phase code of/N number of code period, encoder matrix F '_N×MN number of row vector respectively in code period The transmitting pulse of N number of radar period carry out phase code, encoder matrix F '_N×MM element in each row vector is respectively to phase M subpulse that should be in the cycle carries out phase code.

2. wind profile radar phase coding method according to claim 1, it is characterised in that the transmitting pulse includes M Individual coding subpulse, its transmitted waveform are burst waveforms, encode the time interval with a determination between subpulse.

3. wind profile radar phase coding method according to claim 1, it is characterised in that in step 3, further change Enter to make N meet LM≤N≤N_c/ k, L are positive integers, and k is the arithmetic number for meeting k >=1, and k, L meet the constraint kL >=4, step Encoder matrix F ' is formed in rapid 5_N×MWhen, it is further modified to, in Fei Lanke code matrix Fs_N×NAccording to interval L arbitrarily select M Individual column vector, forms N × M dimension encoder matrix F '_N×M。

4. wind profile radar phase coding method according to claim 1, it is characterised in that in step 3, further change Enter to make N meet (M+1)≤N≤N_c。

5. wind profile radar phase coding method according to claim 1, it is characterised in that in step 3, further change Enter to make N meet L (M+1)≤N≤N_c/ k, and k, L still meet the constraint kL >=4, form encoder matrix F ' in step 5_N×MWhen, enter One step it is improved to, in Fei Lanke code matrix Fs_N×NIn arbitrarily select M column vector according to interval L, form N × M and tie up encoder matrix F′_N×M。

6. a kind of wind profile radar phase code circuit based on Fei Lanke codes, carries out multiple code period transmittings with encoder matrix The phase code of pulse signal, its circuit composition include：Storage circuit (1), sequence circuit (2), DDS circuit (3), amplitude modulation(PAM) Circuit (4), frequency changer circuit (5) and control computer (6), described phase code circuit characterized in that,

Described control computer (6) performs following steps：

Step 3, selects code period number N:According to coding subpulse number M and time domain accumulation number N_cCode period number N is selected, makes N full Sufficient LM≤N≤N_c/ k, L are positive integers, and k is the arithmetic number for meeting k >=1, and k, L meet the constraint kL >=4；

Step 4, adjustment time domain accumulation number N_cWith code period number N:Adjustment time domain accumulation number N_cWith code period number N, N is made_cN_FFT Can be evenly divisible by N, N_FFTIt is the FFT points of FFT spectrum analysis after time domain is accumulated；

Step 5, forms encoder matrix F '_N×M:Select the Fei Lanke code matrix Fs of N-dimensional degree_N×N, in F_N×NAccording to interval L select M Individual column vector, in any order combination form N × M dimension encoder matrix F '_N×M；

Step 6, downloads the time sequence parameter of sequence circuit (2):Time sequence parameter is downloaded to sequence circuit by control signal (105) (2), these parameters include radar period T_r, subpulse number M, subpulse spacing τ_r, subpulse width τ, code period number N, time domain Accumulation number N_cPoints N is analyzed with speed FFT spectrum_FFT；

Step 7, downloads encoder matrix F '_N×MAnd start sequence circuit (2):By control signal (103) by encoder matrix F '_N×MNumber According to downloading to storage circuit (1) and start sequence circuit (2)；

Described storage circuit (1), which is used for the baseband signal data for prestoring a radar period and the coding square downloaded Battle array F '_N×MData, in the presence of the control signal (106) that clock signal (102) and sequence circuit (2) are given, to DDS circuit (3) send N_cN_FFTThe baseband signal (107) of/N number of code period and N_cN_FFTThe encoded signal (108) of/N number of code period；

Described sequence circuit (2), which is used under the driving of clock signal (104), and output control signal (106) is to storage electricity Road (1) is controlled, and makes storage circuit (1) produce baseband signal (107) and encoded signal (108), and produces impulse amplitude control Signal (109) processed is sent to amplitude modulation circuit (4)；

Described DDS circuit (3), which is used under the driving of clock signal (101), completes baseband signal (107) and coding letter The Data Synthesis of number (108) and digital-to-analogue conversion, export the coding intermediate-freuqncy signal (110) of simulation；

Described amplitude modulation circuit (4), which is used under the control of impulse amplitude control signal (109), by the coding of simulation Intermediate-freuqncy signal (110) is modulated to coding medium-frequency pulse signal (111) simulated, and is sent to up-converter circuit (5)；

Described up-converter circuit (5), which is used for the local oscillation signal (112) that will be received and coding medium-frequency pulse signal (111) becomes Frequency is wind profile radar transmitting pulse signal (113).