CN105323021A - Cyclic shift sequence based satellite-borne phased array transmitting antenna calibration method - Google Patents

Abstract

The invention relates to a cyclic shift sequence based satellite-borne phased array transmitting antenna calibration method and system. The method comprises a first step that a satellite-borne phased array transmitting antenna generates a calibration signal and sends the calibration signal to a ground station; a second step that the ground station generates a calibration factor vector according to the calibration signal and feeds the calibration factor vector back to the satellite-borne phased array transmitting antenna through an uplink injection system; and a third step that the satellite-borne phased array transmitting antenna adjusts the amplitude and phase of each transmitting channel according to the calibration factor vector. The method is simple and easy to perform, and can calibrate all transmitting antenna simultaneously, thereby reducing calibration time; and calibration factors of all channels can be obtained by use of only a pair of digital matched filter, so that the complexity of the calibration system is sharply lowered.

Description

Based on the calibration steps of the spaceborne phased array transmitting antenna of cyclically shifted sequences

Technical field

The present invention relates to radar antenna far-field measurement technical field, particularly relate to a kind of calibration steps and system of the spaceborne phased array transmitting antenna based on cyclically shifted sequences.

Background technology

Satellite antenna is the important component part of the payload such as satellite communication, observing and controlling, remote sensing, to the performance important of Satellite Payloads.Phased array antenna has the features such as wave beam rapid scanning, beam shape victory change and space power synthesis, becomes an important development direction of satellite antenna.Due to the particularity of space applied environment, the passage amplitude-phase consistency of spaceborne phased array antenna is vulnerable to the factor impacts such as front thermal deformation, channel temperature drift and device aging, causes its passage consistency to occur time varying characteristic.In order to ensure the performance such as wave beam minor level, beam-pointing accuracy of phased array antenna, except calibrating phased array antenna before satellite launch, also must regularly carry out the calibration of passage amplitude-phase consistency in ground station to the spaceborne phased array antenna in orbit.

At present, phased array antenna calibration steps mainly contains rotating electric field vector (REV) method, normalization transfer encoding (UTE) method and control circuit coding (CCE) method.REV method changes the electric field strength of total electric field vector by the phase shifter controlling array element front end, only need measuring amplitude information, amplitude and the phase value of this rotating vector can be obtained through mathematical computations, but this method needs to measure antenna channels one by one, when array quantity is larger, calibration process needs the at substantial time.UTE and CCE is two kinds and utilizes time-division multiplex orthogonal intersection code signal in the method for far field calibration phased array antenna, encourage mutually with each unit width of switch matrix to spaceborne phased array antenna and encode, decode to received signal in earth base station, thus the width obtaining tested antenna encourages mutually, but the computation complexity of these two kinds of methods is higher.

Summary of the invention

One of them object of the present invention is the calibration steps and the system that provide a kind of spaceborne phased array transmitting antenna based on cyclically shifted sequences, to solve the technical problem that in prior art, the phased array antenna calibration steps alignment time is long, computation complexity is high.

For achieving the above object, embodiments provide a kind of calibration steps of the spaceborne phased array transmitting antenna based on cyclically shifted sequences, comprising:

S1, spaceborne phased array transmitting antenna generate calibrating signal and send to ground station;

S2, described ground station generate correction factor vector according to described calibrating signal and feed back to described spaceborne phased array transmitting antenna;

S3, described spaceborne phased array transmitting antenna are according to the amplitude of each transmission channel of described correction factor vector adjustment and phase place.

Alternatively, obtain described calibrating signal by following steps in described step S1, comprising:

S11, generation code length are the original m sequence c of N ₀(n), and the number of active lanes K obtaining tested transmission channel;

S12, to described original m sequence cyclic shift, shift length is L _offsetindividual code element, to obtain the m sequence code c after cyclic shift _k(n), wherein L _offsetfor being more than or equal to the positive integer of 2;

S13, according to step S12, K-1 cyclic shift is carried out, by original m sequence c to described original m sequence ₀the m sequence code c of (n) and each cyclic shift _kn () is arranged in order and forms m sequence code character, wherein k is positive integer and 1≤k≤K;

S14, utilize described m sequence code character to carry out spread spectrum to complete " 1 " information, and the m sequence code character after spread spectrum is modulated, to obtain calibrating signal.

Alternatively, BPSK is adopted to modulate the m sequence code character after spread spectrum in described step S14.

Alternatively, also comprise after described step S14:

Digital-to-analogue conversion is carried out to obtain missile calibrating signal S to described calibrating signal _k(t), wherein said missile calibrating signal S _kt () adopts following formula to represent:

In formula, 1≤k≤K, K is the quantity of transmission channel to be calibrated, a _kfor the gain of a kth transmission channel, ω _cfor the angular frequency of transmission channel, for the phase place of a kth transmission channel, g (t) is shaping waveform, T _cbe the chip duration of a spreading code, c _kn () is for corresponding to the m sequence code of a kth transmission channel to be calibrated.

Alternatively, obtain correction factor vector by following steps in described step S2, comprising:

S21, reception obtain calibrating signal S after spatial _r(t);

S22, process the calibrating signal S after spatial _rt () is to obtain base-band in-phase signal I (t) and base band quadrature signal Q (t);

S23, described base-band in-phase signal I (t) and described base band quadrature signal Q (t) and original m sequence is utilized to carry out convolution algorithm, to obtain the amplitude phase error estimated value of each transmission channel respectively;

S24, choose any one transmission channel as with reference to passage, utilize amplitude phase error estimated value to obtain relative magnitude and the relative phase of each transmission channel;

S25, generate correction factor vector according to the relative magnitude of each transmission channel and relative phase.

Alternatively, it is characterized in that, obtain amplitude phase error estimated value by following steps in described step S23, comprising:

S231, base-band in-phase signal I (t) and base band quadrature signal Q (t) and original m sequence are carried out convolution algorithm, to obtain signal PI (t) and signal PQ (t);

S232, relevant peaks detection is carried out, to obtain correlation peak to described signal PI (t) and described signal PQ (t);

S232, according to the correlation peak obtained in step S232, calculate the width phase factor α of each transmission channel _kand β _k, then calculate the range error estimated value of each transmission channel.

Second aspect, the embodiment of the present invention additionally provides a kind of calibration system of the spaceborne phased array transmitting antenna based on cyclically shifted sequences, comprising: spaceborne phased array transmitting antenna and ground station, wherein:

Described spaceborne phased array transmitting antenna, sends to described ground station for generating calibrating signal, and adjusts amplitude and the phase place of each transmission channel according to the correction factor vector that described ground station feeds back;

Described ground station, for generating correction factor vector according to described calibrating signal and feeding back to described spaceborne phased array transmitting antenna.

Alternatively, described spaceborne phased array transmitting antenna comprises:

Described calibrating signal generating apparatus, for generating calibrating signal;

Described transmitting channel correction device, for transmitting calibrating signal or correcting transmission channel according to correction factor;

Described digiverter, for carrying out described calibrating signal the calibrating signal that digital-to-analogue conversion obtains analog form;

Described transmitting terminal radio frequency handling device, for carrying out up-conversion by the calibrating signal of simulation and carrying out power amplification;

Described phased array transmitting antenna, is sent to described receiving terminal radio frequency handling device for the calibrating signal by up-conversion and after power amplification;

Described correction factor receiving system, is sent to described transmitting channel correction device for the described correction factor vector that receives from described correction factor dispensing device.

Alternatively, described ground station comprises:

Described receiving terminal radio frequency handling device, for carrying out demodulation to obtain the calibrating signal after spatial to received signal;

Described sampling apparatus, for the calibrating signal after spatial of sampling to obtain the calibrating signal after spatial of digital form;

Described correction factor generating apparatus, for generating correction factor vector according to the calibrating signal after spatial of digital form;

Described correction factor dispensing device, for being sent to correction factor receiving system by described correction factor vector.

The embodiment of the present invention produces multiple spreading code by carrying out repeatedly cyclic shift to original m sequence.When number of active lanes increases, the m sequence that only needs one are longer just can realize calibration, and scheme is simple and easy to do, saves a yard resource.In practical application, the present invention only needs use a pair identical digital matched filter just can obtain the calibration factor of all passages, substantially reduces system complexity.

Accompanying drawing explanation

Can understanding the features and advantages of the present invention clearly by reference to accompanying drawing, accompanying drawing is schematic and should not be construed as and carry out any restriction to the present invention, in the accompanying drawings:

Fig. 1 is the calibration steps flow chart of a kind of spaceborne phased array transmitting antenna based on cyclically shifted sequences that the embodiment of the present invention provides;

Fig. 2 is the calibrating signal generative process flow chart that the embodiment of the present invention provides;

Fig. 3 is the calibration system structure chart of a kind of spaceborne phased array transmitting antenna based on cyclically shifted sequences that the embodiment of the present invention provides.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail.Following examples for illustration of the present invention, but are not used for limiting the scope of the invention.

First aspect, embodiments provides a kind of calibration steps of the spaceborne phased array transmitting antenna based on cyclically shifted sequences, as shown in Figure 1, comprising:

S1, spaceborne phased array transmitting antenna generate calibrating signal and send to ground station;

S2, ground station generate correction factor vector according to above-mentioned calibrating signal and feed back to above-mentioned spaceborne phased array transmitting antenna;

S3, this spaceborne phased array transmitting antenna are according to the amplitude of each transmission channel of above-mentioned correction factor vector adjustment and phase place.

Below the calibration steps of the spaceborne phased array transmitting antenna based on cyclically shifted sequences that the embodiment of the present invention provides is elaborated.

First, introduce S1, spaceborne phased array transmitting antenna generates calibrating signal and send to the step of ground station.

In practical application, spaceborne phased array transmitting antenna obtains calibrating signal by following steps, as shown in Figure 2, comprising:

S11, spaceborne phased array transmitting antenna produce the original m sequence c that a code length is N ₀(n), and the number of active lanes K obtaining tested transmission channel;

S12, to described original m sequence cyclic shift, shift length is L _offsetindividual code element, to obtain the m sequence code c after cyclic shift _k(n), wherein L _offsetfor being more than or equal to the positive integer of 2;

S13, according to step S12, K-1 cyclic shift is carried out, by original m sequence c to described original m sequence ₀the m sequence code c of (n) and each cyclic shift _kn () is arranged in order and forms m sequence code character, wherein k is positive integer and 1≤k≤K;

S14, utilize described m sequence code character to carry out spread spectrum to complete " 1 " information, and the m sequence code character after spread spectrum is modulated, to obtain calibrating signal.

In practical application, alternatively, BPSK in step S14, is adopted to modulate the m sequence code character after spread spectrum, and using the signal after modulation as calibrating signal.Certain those skilled in the art can according to concrete use scenes, and select other modulator approaches to obtain calibrating signal, the present invention is not construed as limiting.

In practical application, the school signal of acquisition also needs digital-to-analogue conversion before being gone out by phase control emission antenna transmission, comprising:

Digital-to-analogue conversion is carried out to obtain missile calibrating signal S to calibrating signal _k(t), wherein said missile calibrating signal S _kt () adopts following formula to represent:

In formula, 1≤k≤K, K is the quantity of transmission channel to be calibrated, a _kfor the gain of a kth transmission channel, ω _cbe the angular frequency of transmission channel, for the phase place of a kth transmission channel, g (t) is shaping waveform, T _cbe the chip duration of a spreading code, c _kn () is for corresponding to the m sequence code of a kth transmission channel to be calibrated.

Secondly, introduce S2, ground station generate correction factor vector according to described calibrating signal and feed back to the step of described spaceborne phased array transmitting antenna.

In practical application, ground station obtains correction factor vector by following steps, comprising:

S21, obtain the calibrating signal S after spatial _r(t);

S22, process the calibrating signal S after spatial _rt () is to obtain base-band in-phase signal I (t) and base band quadrature signal Q (t);

S23, base-band in-phase signal I (t) and base band quadrature signal Q (t) and original m sequence is utilized to carry out convolution algorithm (i.e. matched filtering), to obtain the amplitude phase error estimated value of each transmission channel respectively;

S24, choose any one transmission channel as with reference to passage, utilize amplitude phase error estimated value to obtain relative magnitude and the relative phase of each transmission channel;

S25, generate correction factor vector according to the relative magnitude of each transmission channel and relative phase.

Wherein, step S21: the antenna at far field place receive after spatial such as formula the calibrating signal S shown in (2) _r(t):

In formula, 1≤k≤K, K is the quantity of transmission channel to be calibrated, a _kfor the gain of a kth transmission channel, ω _cfor the angular frequency of transmission channel, for the phase place of a kth transmission channel, g (t) is shaping waveform, T _cbe the chip duration of a spreading code, c _kn (), for corresponding to the m sequence code of a kth transmission channel to be calibrated, n (t) is noise, and B is the loss of calibrating signal after spatial.

Will be understood that, g (t) refers to base band shaping waveform for shaping waveform.Baseband signal bandwidth is infinitely great, needs to limit its bandwidth; Simultaneously in order to overcome intersymbol interference, so needed before ovennodulation with a formed filter in baseband signal, the waveform after formed filter is exactly g (t).

Will be understood that, a data-signal (as logical one or 0) is encoded with multiple code signal usually, and so one of them code signal is just called a chip, and the logical one in such as spreading code or 0 just can be considered as a chip.The chip duration of a spreading code just refers to, the logical one in previously mentioned spreading code or the duration of 0.

Wherein, step S22: the calibrating signal S after spatial _rt () is through low noise amplifier, down-converted, digital signal is obtained again through analog-to-digital conversion sampling, eventually pass orthogonal digital down-conversion, digital matched filtering obtain base-band in-phase signal I (t) and base band quadrature signal Q (t), be shown below:

$I\left(t\right)=B\underset{k=1}{\overset{K}{\Σ}}\underset{n=0}{\overset{N-1}{\Σ}}{g}_D(t-{\mathrm{nT}}_c)c_k\left(n\right){\mathrm{\α}}_k+n_I\left(t\right)---\left(3\right)$

$Q\left(t\right)=B\underset{k=1}{\overset{K}{\Σ}}\underset{n=0}{\overset{N-1}{\Σ}}{g}_D(t-{\mathrm{nT}}_c)c_k\left(n\right){\mathrm{\β}}_k+n_Q\left(t\right)---\left(4\right)$

In formula, g ^*t conjugate transpose that () is g (t), n _i(t), n _qt () is respectively the noise of baseband inphase and base band quadrature branch road.

Wherein, step S23: the amplitude phase error estimated value obtaining each transmission channel comprises:

S231, base-band in-phase signal I (t) and base band quadrature signal Q (t) and original m sequence are carried out convolution algorithm (matched filtering), obtain signal PI (t) after matched filtering and PQ (t), wherein:

$PI\left(t\right)=c^{*}\left(n\right)\⊗I\left(t\right),---\left(5\right)$

$PQ\left(t\right)=c^{*}\left(n\right)\⊗Q\left(t\right),---\left(6\right)$

In formula, c ^*n () is the conjugate transpose of original m sequence, for convolution algorithm.

S232, relevant peaks detection is carried out to signal PI (t) after matched filtering and PQ (t).From character and the digital matched filtering principle of original m sequence, after digital matched filtering, there is K relevant peaks in each cycle of signal PI (t) and PQ (t), be shown below:

$PI\left(t\right)=B\underset{k=1}{\overset{K}{\Σ}}{\mathrm{PI}}_k\·g_D\[t-\left(k-1\right)\·L_{offset}\·T_c\]+c^{*}\left(n\right)\⊗n_I\left(t\right)---\left(7\right)$

$PQ\left(t\right)=B\underset{k=1}{\overset{K}{\Σ}}{\mathrm{PQ}}_k\·g_D\[t-\left(k-1\right)\·L_{offset}\·T_c\]+c^{*}\left(n\right)\⊗n_Q\left(t\right)---\left(8\right)$

In formula (7) and formula (8), L _offsetfor symbol offset number, PI _k, PQ _kfor the value of each relevant peaks in signal PI (t) and PQ (t) each cycle, be expressed as follows:

PI _k＝-α ₁-α ₂-…+N·α _k-α _k+1-…-α _K，(9)

PQ _k＝-β ₁-β ₂-…+N·β _k-β _k+1-…-β _K，(10)

In formula, 1≤k≤K.

S233: the I/Q width phase factor α calculating each transmission channel according to the relevant peaks obtained in step S232 _kand β _k, then calculate the range error estimated value of each transmission channel.

The I/Q width phase factor α of each transmission channel _kand β _kemploying following methods solves:

1, by the PI in step S232 _kadopt matrix representation:

$\left[\begin{array}{c}P{I}_1\\ {\mathrm{PI}}_2\\ ...\\ P{I}_K\end{array}\right]=B\×{\left[\begin{array}{ccccc}N& -1& -1& ...& -1\\ -1& N& -1& ...& -1\\ ...& ...& ...& ...& ...\\ -1& -1& -1& ...& N\end{array}\right]}_{K\×K}\×{\left[\begin{array}{ccccc}{\mathrm{\α}}_1& 0& 0& ...& 0\\ 0& {\mathrm{\α}}_2& 0& ...& 0\\ ...& ...& ...& ...& ...\\ 0& 0& 0& ...& {\mathrm{\α}}_k\end{array}\right]}_{K\×K}\×\left[\begin{array}{c}1\\ 1\\ ...\\ 1\end{array}\right]+n---\left(11\right)$

Be designated as: P=BTAb+n.

In formula, n is noise vector; P is the column vector be made up of correlation peak; A is by α ₁to α _kthe diagonal matrix of composition; B is information sequence, and because calibrating signal adopts complete " 1 " information sequence, therefore b is a K dimensional vector.On the right side of equation, leftmost K × K matrix is the cross-correlation matrix of original m sequence and the m sequence code character with chip offset, is denoted as T.This matrix has special form of inverting, and the form of its inverse matrix is such as formula shown in (12):

$T^{-1}={\left[\begin{array}{ccccc}b& a& a& ...& a\\ a& b& a& ...& a\\ ...& ...& ...& ...& ...\\ a& a& a& ...& b\end{array}\right]}_{K\×K}---\left(12\right)$

In formula, a with b is only relevant with code length N constant, and the complexity of this matrix inversion is very little.

2, by the matrix notation in step 1, according to the principle of decorrelation Multiuser Detection, width phase factor α is solved _k, solution procedure can be expressed as follows:

T ^-1P＝BAb+T ^-1n(13)

And can be converted to:

$\left[\begin{array}{c}{\mathrm{\α}}_1\\ {\mathrm{\α}}_2\\ ...\\ {\mathrm{\α}}_K\end{array}\right]=\frac{1}{B}\×\left(T^{-1}\×{\left[\begin{array}{c}P{I}_1\\ {\mathrm{PI}}_2\\ ...\\ P{I}_K\end{array}\right]}_{K\×K}-T^{-1}n\right)---\left(14\right)$

By solution procedure above and Signal estimation theory, α _kestimated value be expressed as follows:

$\widehat{{\mathrm{\α}}_k}=\frac{1}{B}\×\[\left(b-a\right)\·{\mathrm{PI}}_k+a\underset{i=1}{\overset{K}{\mathrm{\Σ}}}{\mathrm{PI}}_i\]---\left(15\right)$

As can be seen from formula (15), only need to detect the relevant peaks exported in one end of matched filter, after a spreading code cycle has caught all relevant peaks, just can obtain width phase factor estimated value according to equation above and the accuracy of amplitude phase error estimated value is only affected by noise, completely eliminate the multi-access inference of the system of general employing non-orthogonal spreading codes work.

3, solve according to the method identical with step 2 with step 1 calculate the amplitude phase error estimated value of a kth passage as follows.

$\widehat{a_k}=\sqrt{{\widehat{a_k}}^2+{\widehat{{\mathrm{\β}}_k}}^2},---\left(16\right)$

Obtained with for the amplitude phase error estimated value of a kth transmission channel.

Using some transmission channel q as with reference to passage, calculate other passages relative to the relative amplitude of this passage and relative phase, according to tried to achieve relative amplitude and the relative phase calculation correction factor, send back transmitting terminal and calibrate.

If examine passage with transmission channel q (1≤q≤K), relative amplitude and relative phase are:

$\stackrel{\‾}{a_k}=10*{\log }_{10}\left(\frac{\widehat{{\mathrm{\α}}_k}}{\widehat{{\mathrm{\α}}_q}}\right),---\left(18\right)$

In formula (18) and formula (19), 1≤k≤K, k ≠ q.

Wherein with represent relative amplitude (unit: dB) and the relative phase (unit: degree) of other passages except reference channel.

Hypothetical reference path is passage 1, and the vector of correction factor composition can be expressed as follows:

Finally introduce S3, spaceborne phased array transmitting antenna according to the amplitude of each transmission channel of correction factor vector adjustment and phase place.

After spaceborne phased array transmitting antenna receives correction factor vector, corresponding transmission channel is adjusted.

In practical application, original m sequence is identical with general frequency expansion sequence with the m sequence code character of the m Sequence composition through displacement, may be used to adopt in the communication system of spectrum spreading method.But general frequency expansion sequence produces needs linear feedback shift register.Such as when 5 transmission channels, then need 5 linear feedback shift registers to produce 5 groups of m sequences, and need employing 5 groups of matched filters, therefore resource consumption is very large.In system provided by the invention, adopt in the scheme of Phase shift m sequence and only need 1 linear feedback shift register just can produce an original m sequence, 4 m sequences after being shifted are obtained by 4 displacements, form a m sequence code character, and only need 1 group of matched filter just can obtain the correction factor of 5 transmission channels at receiving terminal.The invention provides needs 1 group of matched filter and can have identical effect with the code character produced by 5 linear feedback shift registers, greatly save resource.

For embodying the superiority of the calibration steps of the spaceborne phased array transmitting antenna based on cyclically shifted sequences that the embodiment of the present invention provides, second aspect, the embodiment of the present invention additionally provides a kind of calibration system of the spaceborne phased array transmitting antenna based on cyclically shifted sequences, as shown in Figure 3, comprise: spaceborne phased array transmitting antenna and ground station, wherein:

Spaceborne phased array transmitting antenna, sends to described ground station for generating calibrating signal, and adjusts amplitude and the phase place of each transmission channel according to the correction factor vector that described ground station feeds back;

Ground station, for generating correction factor vector according to above-mentioned calibrating signal and feeding back to above-mentioned spaceborne phased array transmitting antenna.

Alternatively, spaceborne phased array transmitting antenna mentioned above comprises:

Calibrating signal generating apparatus, for generating calibrating signal;

Transmitting channel correction device, for transmitting calibrating signal or correcting transmission channel according to correction factor;

Digiverter, for carrying out described calibrating signal the calibrating signal that digital-to-analogue conversion obtains analog form;

Transmitting terminal radio frequency handling device, for carrying out up-conversion by the calibrating signal of simulation and carrying out power amplification;

Phased array transmitting antenna, is sent to described receiving terminal radio frequency handling device for the calibrating signal by up-conversion and after power amplification;

Correction factor receiving system, is sent to described transmitting channel correction device for the described correction factor vector that receives from described correction factor dispensing device.

Alternatively, described ground station comprises:

Receiving terminal radio frequency handling device, for carrying out demodulation to obtain the calibrating signal after spatial to received signal;

Sampling apparatus, for the calibrating signal after spatial of sampling to obtain the calibrating signal after spatial of digital form;

Correction factor generating apparatus, for generating correction factor vector according to the calibrating signal after spatial of digital form;

Correction factor dispensing device, for being sent to correction factor receiving system by described correction factor vector.

The calibration system course of work of the spaceborne phased array transmitting antenna based on cyclically shifted sequences that the embodiment of the present invention provides is as follows:

Spaceborne phased array transmitting antenna calibration signal generating apparatus generates calibrating signal according to step mentioned above, and this calibrating signal is transferred to digiverter through transmitting channel correction device; Calibrating signal is carried out the calibrating signal that digital-to-analogue conversion generates analog form by this digiverter; Through being sent to ground station by phased array transmitting antenna after the calibrating signal of analog form is carried out up-conversion and power amplification by transmitting terminal radio frequency handling device.

Receiving terminal radio frequency handling device in ground station receives the signal after spatial and carries out demodulation acquisition calibrating signal; Sampling apparatus is sampled to the calibrating signal after spatial, thus obtains the calibrating signal of digital form; The calibrating signal of correction factor generating apparatus to this digital form processes thus generates correction factor vector and be transferred to spaceborne phased array transmitting antenna by correction factor dispensing device.

Correction factor receiving system in spaceborne phased array transmitting antenna is sent to transmitting channel correction device after receiving the correction factor vector from ground station, is corrected each transmission channel by this transmitting channel correction device.

In sum, the calibration steps of the spaceborne phased array transmitting antenna based on cyclically shifted sequences that the embodiment of the present invention provides and system, multiple spreading code is produced when number of active lanes increases by carrying out repeatedly cyclic shift to original m sequence, only need the m sequence that longer, scheme is simple and easy to do, saves a yard resource.In practical application, the present invention only needs use a pair identical digital matched filter just can obtain multiple relevant peaks, substantially reduces system complexity.The present invention adopts decorrelation Multiuser Detection to eliminate multi-access inference.Decorrelation computing relates to the inversion operation T of frequency expansion sequence cross-correlation matrix ^-1with the multiplying T of matrix with vector ^-1p.General K × K matrix inversion operation complexity is very high, and complexity is O (K ³).But the cross-correlation matrix with the m sequence code character of code skew has the form of special matrix, the form of its inverse matrix is identical with original matrix, and only follow the length N of m sequence relevant, therefore its operand known can be ignored compared with general K × K matrix inversion operation.The multiplying of general matrix (K × K) and vector (K × 1) needs K ²secondary complex multiplication and complex addition, and matrix multiplication here only needs 2K sub-addition and 2K complex multiplication, can know and only need little operand just can realize whole decorrelation process.

Although describe embodiments of the present invention by reference to the accompanying drawings, but those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, such amendment and modification all fall into by within claims limited range.

Claims (9)

1., based on a calibration steps for the spaceborne phased array transmitting antenna of cyclically shifted sequences, it is characterized in that, comprising:

S1, spaceborne phased array transmitting antenna generate calibrating signal and send to ground station;

S2, described ground station generate correction factor vector according to described calibrating signal and feed back to described spaceborne phased array transmitting antenna;

S3, described spaceborne phased array transmitting antenna are according to the amplitude of each transmission channel of described correction factor vector adjustment and phase place.

2. the calibration steps of spaceborne phased array transmitting antenna according to claim 1, is characterized in that, obtains described calibrating signal, comprising in described step S1 by following steps:

S11, generation code length are the original m sequence c of N ₁(n), and the number of active lanes K obtaining tested transmission channel;

S12, to described original m sequence cyclic shift, shift length is L _offsetindividual code element, to obtain the m sequence code c after cyclic shift _k(n), wherein L _offsetfor being more than or equal to the positive integer of 2;

S13, according to step S12, K-1 cyclic shift is carried out, by original m sequence c to described original m sequence ₁the m sequence code c of (n) and each cyclic shift _kn () is arranged in order and forms m sequence code character, wherein k is positive integer and 1≤k≤K;

S14, utilize described m sequence code character to carry out spread spectrum to complete " 1 " information, and the m sequence code character after spread spectrum is modulated, to obtain calibrating signal.

3. the calibration steps of spaceborne phased array transmitting antenna according to claim 2, is characterized in that, adopts BPSK to modulate the m sequence code character after spread spectrum in described step S14.

4. the calibration steps of spaceborne phased array transmitting antenna according to claim 2, is characterized in that, also comprises after described step S14:

Digital-to-analogue conversion is carried out to obtain missile calibrating signal S to described calibrating signal _k(t), wherein said missile calibrating signal S _kt () adopts following formula to represent:

In formula, 1≤k≤K, K is the quantity of transmission channel to be calibrated, a _kfor the gain of a kth transmission channel, ω _cfor the angular frequency of transmission channel, for the phase place of a kth transmission channel, g (t) is shaping waveform, T _cbe the chip duration of a spreading code, c _kn () is for corresponding to the m sequence code of a kth transmission channel to be calibrated.

5. the calibration steps of spaceborne phased array transmitting antenna according to claim 1, is characterized in that, obtains correction factor vector, comprising in described step S2 by following steps:

S21, reception obtain calibrating signal S after spatial _r(t);

S22, process the calibrating signal S after spatial _rt () is to obtain base-band in-phase signal I (t) and base band quadrature signal Q (t);

S23, described base-band in-phase signal I (t) and described base band quadrature signal Q (t) and original m sequence is utilized to carry out convolution algorithm, to obtain the amplitude phase error estimated value of each transmission channel respectively;

S24, choose any one transmission channel as with reference to passage, utilize amplitude phase error estimated value to obtain relative magnitude and the relative phase of each transmission channel;

S25, generate correction factor vector according to the relative magnitude of each transmission channel and relative phase.

6. the calibration steps of spaceborne phased array transmitting antenna according to claim 5, is characterized in that, obtains amplitude phase error estimated value, comprising in described step S23 by following steps:

S231, base-band in-phase signal I (t) and base band quadrature signal Q (t) and original m sequence are carried out convolution algorithm, to obtain signal PI (t) and signal PQ (t);

S232, relevant peaks detection is carried out, to obtain correlation peak to described signal PI (t) and described signal PQ (t);

S232, according to the correlation peak obtained in step S232, calculate the width phase factor α of each transmission channel _kand β _k, then calculate the range error estimated value of each transmission channel.

7. based on a calibration system for the spaceborne phased array transmitting antenna of cyclically shifted sequences, it is characterized in that, comprising: spaceborne phased array transmitting antenna and ground station, wherein:

Described spaceborne phased array transmitting antenna, sends to described ground station for generating calibrating signal, and adjusts amplitude and the phase place of each transmission channel according to the correction factor vector that described ground station feeds back;

Described ground station, for generating correction factor vector according to described calibrating signal and feeding back to described spaceborne phased array transmitting antenna.

8. calibration system according to claim 7, is characterized in that, described spaceborne phased array transmitting antenna comprises:

Described calibrating signal generating apparatus, for generating calibrating signal;

Described transmitting channel correction device, for transmitting calibrating signal or correcting transmission channel according to correction factor;

Described digiverter, for carrying out described calibrating signal the calibrating signal that digital-to-analogue conversion obtains analog form;

Described transmitting terminal radio frequency handling device, for carrying out up-conversion by the calibrating signal of simulation and carrying out power amplification;

Described phased array transmitting antenna, is sent to described receiving terminal radio frequency handling device for the calibrating signal by up-conversion and after power amplification;

Described correction factor receiving system, is sent to described transmitting channel correction device for the described correction factor vector that receives from described correction factor dispensing device.

9. calibration system according to claim 7, is characterized in that, described ground station comprises:

Described receiving terminal radio frequency handling device, for carrying out demodulation to obtain the calibrating signal after spatial to received signal;

Described sampling apparatus, for the calibrating signal after spatial of sampling to obtain the calibrating signal after spatial of digital form;

Described correction factor generating apparatus, for generating correction factor vector according to the calibrating signal after spatial of digital form;

Described correction factor dispensing device, for being sent to correction factor receiving system by described correction factor vector.