CN113125883B

CN113125883B - Performance test system and method for third-order digital correlator

Info

Publication number: CN113125883B
Application number: CN202110341641.3A
Authority: CN
Inventors: 于哲; 刘浩; 牛立杰; 韩东浩
Original assignee: National Space Science Center of CAS
Current assignee: National Space Science Center of CAS
Priority date: 2021-03-30
Filing date: 2021-03-30
Publication date: 2024-07-09
Anticipated expiration: 2041-03-30
Also published as: CN113125883A

Abstract

The invention belongs to the technical field of space microwave remote sensing, and particularly relates to a performance test system and method for a third-order digital correlator, wherein the performance test system comprises the following steps: the data parameter setting module is used for simultaneously sending setting parameters of the multi-path required excitation noise signals to the data generating module; the data generation module is used for correspondingly generating four excitation noise signals of any waveform according to the set parameters of the transmitted excitation noise signals; the data transmitting and processing module is used for respectively performing digital-to-analog conversion on the four excitation noise signals to respectively obtain corresponding noise analog signals, and sequentially inputting the corresponding noise analog signals to the third-order digital correlator to be tested; and testing the related bias performance, the related efficiency performance, the stability performance, the linearity performance and the phase error performance of the third-order digital correlator to be tested to obtain a corresponding test result, and completing the performance test of the third-order digital correlator.

Description

Performance test system and method for third-order digital correlator

Technical Field

The invention belongs to the technical field of space microwave remote sensing, and particularly relates to a performance test system and method for a third-order digital correlator.

Background

The comprehensive aperture radiometer can utilize an antenna array formed by small-caliber antennas to equivalently amplify a real-caliber antenna, thereby reducing the cost and the processing difficulty of the antenna. The digital correlator is a key component for realizing quantitative measurement of the comprehensive aperture radiometer, and has the core function of realizing complex correlation operation between any two channels, and the accuracy of the complex correlation result of the third-order digital correlator directly determines the accuracy and precision of the measurement result of the comprehensive aperture microwave radiometer system so as to influence the key performance index of the radiometer system, so that a multi-channel digital correlator performance test method is needed. However, most of the existing performance test methods of the comprehensive aperture radiometer correlator are carried out along with system tests, quantitative evaluation is difficult to carry out, and an effective means is lacking for carrying out quantitative evaluation test on the digital correlator. The main function of the digital correlator in the comprehensive aperture radiometer is to digitally quantize the noise signal through the ADC chip, then to perform parallel complex correlation operation in the digital correlator and to transmit the correlation result in the form of data to the upper computer. The number of the comprehensive aperture radiometer units is large, and the number of the correlator units is proportional to the square of the number of the antenna units, so that the comprehensive aperture radiometer adopts a digital correlator. The larger the quantization order of the digital correlator, the smaller the quantization noise and the higher the accuracy, but the power consumption and cost are greatly increased, and the number of gates of the digital correlator is also increased, thereby resulting in an increase in the complexity of the synthetic aperture radiometer.

Currently, a third-order quantization correlator is adopted, the signal-to-noise ratio can reach 81% of that of an analog correlator, and only a high quantization level and a low quantization level are adopted, so that the circuit is simpler.

In the existing test system of the digital correlator, more electronic devices forming the test system are complex in structure, the system complexity is high, inter-channel crosstalk is easily caused by a noise source through a diode, an amplifier and a filter, the amplifier is self-excited, distortion of an output signal of the comprehensive aperture radiometer is caused, the correlation degree of the output signal is greatly reduced, and phase traversal of 0-360 degrees cannot be performed for the test of the correlation noise phase difference of the digital correlator.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a performance test method for a third-order digital correlator, which can realize high-precision quantitative test and evaluation of the third-order digital correlator; the input end of the test system is provided with the multichannel digital-analog converter, so that noise signals with any correlation degree can be quantitatively input, and various index parameters of sampling rate, bandwidth, variance and integral duration of the noise signals can be set at will. The memory of the multichannel digital-analog converter has a large storage space, the output signal is long enough, and the correlation precision of the output signal can meet the test requirement of a high-precision digital correlator.

The invention provides a performance test system for a third-order digital correlator, which is arranged on a control console and comprises: the device comprises a data parameter setting module, a data generating module and a data transmitting and processing module;

The data parameter setting module is used for simultaneously sending setting parameters of the multi-path required excitation noise signals to the data generating module;

The data generation module is used for correspondingly generating a first excitation noise signal, a second excitation noise signal, a third excitation noise signal and a fourth excitation noise signal of any waveform according to the set parameters of the transmitted excitation noise signals;

The data transmitting and processing module is used for respectively performing digital-to-analog conversion on the first excitation noise signal, the second excitation noise signal, the third excitation noise signal and the fourth excitation noise signal to respectively obtain corresponding noise analog signals, and sequentially inputting the corresponding noise analog signals to the third-order digital correlator to be tested; and testing the related bias performance, the related efficiency performance, the stability performance, the linearity performance and the phase error performance of the third-order digital correlator to be tested to obtain a corresponding test result, and completing the performance test of the third-order digital correlator.

As one of the improvements of the above technical solutions, the test system further includes: and the evaluation analysis module is used for respectively evaluating and analyzing the related bias performance, the related efficiency performance, the stability performance, the linearity performance and the phase error performance of the third-order digital correlator to be tested according to the obtained test result.

As one of the improvements of the above technical solutions, the data generating module includes:

the first excitation signal generation unit is used for correspondingly generating multiple uncorrelated Gaussian white noise band-limit signals with the integration time length of 2.4s and the bandwidth of 100M according to the setting parameters of the excitation noise signals sent by the data transmission and processing terminal, so as to obtain multiple groups of first excitation noise signals;

The second excitation signal generating unit is used for correspondingly generating multipath Gaussian white noise band-limited signals with integration duration of 2.4s, correlation coefficient starting from 0 and 100M bandwidth, which are gradually increased by 0.1, as a plurality of groups of second excitation noise signals according to the setting parameters of the excitation noise signals sent by the data transmitting and processing terminal;

The third excitation signal generation unit is used for correspondingly generating multiple Gaussian white noise band-limited signals with integration duration of 2.4s, correlation coefficient of (0:10 ^-4：5×10^-4) and 100M bandwidth according to the setting parameters of the excitation noise signals sent by the data transmission and processing terminal, and the multiple Gaussian white noise band-limited signals are used as multiple groups of third excitation noise signals; and

And the fourth excitation signal generation unit is used for correspondingly generating two groups of Gaussian white noise band-limited signals CHi signals and CHj signals with analog correlation coefficients of 0.04+j0.02 as fourth excitation noise signals according to the setting parameters of the excitation noise signals sent by the data transmission and processing terminal.

As one of the improvements of the above technical solutions, the data sending and processing module includes:

The first data transmitting and processing unit is used for performing digital-to-analog conversion on each Gaussian white noise band-limited signal in each group of first excitation noise signals to obtain a plurality of paths of first noise analog signals, inputting the first noise analog signals of each path to the third-order digital correlator to be tested, and testing the related bias performance of the third-order digital correlator to be tested to obtain a plurality of first test results;

The second data transmitting and processing unit is used for performing digital-to-analog conversion on each Gaussian white noise band-limited signal in each group of second excitation noise signals to obtain a plurality of paths of second noise analog signals, and inputting the second analog signals of each path to a third-order digital correlator to be detected; testing the related efficiency performance of the third-order digital correlator to be tested to obtain a plurality of second test results;

The third data transmitting and processing unit is used for performing digital-to-analog conversion on each path of Gaussian white noise band-limited signal in each group of third excitation noise signals to obtain a plurality of paths of third noise analog signals, and inputting the third analog signals of each path of third noise analog signals to a third-order digital correlator to be detected; testing the linearity performance of the third-order digital correlator to be tested to obtain a third test result;

the fourth data transmitting and processing unit is used for performing digital-to-analog conversion on each path of Gaussian white noise band-limited signal in the third excitation noise signal to obtain a plurality of paths of third noise analog signals, and inputting the third noise analog signals of each path of third noise analog signals to a third-order digital correlator to be detected; testing the stability performance of the third-order digital correlator to be tested to obtain a fourth test result; and

The fifth data transmitting and processing unit is used for performing digital-to-analog conversion on each path of Gaussian white noise band-limited signal in the fourth excitation noise signal to obtain a plurality of paths of fourth noise analog signals, and inputting the fourth noise analog signals of each path of the fourth noise analog signals to a third-order digital correlator to be detected; and testing the related phase error performance of the third-order digital correlator to be tested to obtain a fifth test result.

As one of the improvements of the above technical solution, the specific process of the first data sending and processing unit is:

Randomly selecting a group of first excitation noise signals, performing digital-to-analog conversion on two paths of uncorrelated Gaussian white noise band-limited signals in the group of first excitation noise signals to obtain two paths of first noise analog signals, and inputting the first noise analog signals of each path to k and j channels of a third-order digital correlator to be detected; wherein the k and j channels are optional two channels;

Calculating a first analog correlation coefficient for the set of first excitation noise signals:

wherein, The method comprises the steps that a first analog correlation coefficient of k and j channels of a third-order digital correlator to be detected is obtained; c ₁ is the first conversion coefficient; c ₃ is a second conversion coefficient; c ₅ is a third conversion coefficient; r _kj is the cross correlation of the k and j channels of the three-order digital correlator to be detected;

wherein,

S _k (n) is a digital sequence of the first analog signal of the k channel of the third-order digital correlator to be detected after third-order quantization; s _j (n) is a digital sequence of the first analog signal of the j channel of the third-order digital correlator to be detected after third-order quantization; n is the number of integration points:

Wherein k _k is the quantization threshold of the k channel of the third-order digital correlator to be detected; k _j is the quantization threshold of the j channel of the third-order digital correlator to be tested;

wherein,

Wherein phi is a probability distribution function of standard normal distribution; The variance of the k channel of the third-order digital correlator to be tested is obtained; s _k is the autocorrelation of the k channel of the third-order digital correlator to be tested;

wherein,

Wherein,The variance of the j channel of the third-order digital correlator to be tested is obtained; s _j is the autocorrelation of the j channel of the third-order digital correlator to be tested;

According to the real analog correlation coefficient calculated in the third-order digital correlator of the group of first excitation noise signals, calculating the correlation bias u _bias of the third-order digital correlator to be tested of the group of first excitation noise signals:

wherein, The real analog correlation coefficient is obtained by soft simulation calculation of third-order quantized data of the group of first excitation noise signals in a third-order digital correlator to be detected;

taking the related bias u _bias of the third-order digital correlator to be tested as a first test result;

And repeating the process, inputting each group of first excitation noise signals into the third-order digital correlator to be tested, and performing correlation bias test on the third-order digital correlator to be tested to obtain correlation biases of a plurality of third-order digital correlators to be tested, thereby obtaining a plurality of first test results.

As one of the improvements of the above technical solutions, the specific process of the second data sending and processing unit is as follows:

Optionally selecting a group of second excitation noise signals, performing digital-to-analog conversion on two paths of correlated Gaussian white noise band-limited signals in the group of second excitation noise signals to obtain a plurality of paths of second noise analog signals, and inputting the second analog signals of each path to two k and j channels of a third-order digital correlator to be detected; wherein the k and j channels are optional two channels;

calculating a second analog correlation coefficient for the set of second excitation noise signals:

wherein, The second analog correlation coefficient of the k and j channels of the third-order digital correlator to be detected; c ₁ is the first conversion coefficient; c ₃ is a second conversion coefficient; c ₅ is a third conversion coefficient; r _kj-1 is the first cross correlation of the k and j channels of the third-order digital correlator to be detected;

wherein,

S _k-1 (n) is a digital sequence of the second analog signal of the k channel of the third-order digital correlator to be detected after third-order quantization; s _j-1 (n) is a digital sequence of the second analog signal of the j channel of the third-order digital correlator to be detected after third-order quantization; n is the number of integration points:

wherein,

Calculating the correlation efficiency eta of the third-order digital correlator to be tested of the set of second excitation noise signals by using the first test result u _bias:

taking the correlation efficiency eta of the third-order digital correlator to be tested as a second test result;

And repeating the process, inputting each group of second excitation noise signals into the third-order digital correlator to be tested, and testing the correlation efficiency of the third-order digital correlator to be tested to obtain the correlation efficiency of a plurality of third-order digital correlators to be tested, thereby obtaining a plurality of second test results.

As one of the improvements of the above technical solution, the specific process of the third data sending and processing unit is as follows:

Optionally selecting a group of third excitation noise signals, performing digital-to-analog conversion on two paths of correlated Gaussian white noise band-limited signals in the group of third excitation noise signals to obtain multiple paths of third noise analog signals, and inputting the third analog signals of each path to two k and j channels of a third-order digital correlator to be detected; wherein the k and j channels are optional two channels;

Calculating a third analog correlation coefficient for the set of third excitation noise signals:

wherein, The third analog correlation coefficient of the k and j channels of the third-order digital correlator to be detected; c ₁ is the first conversion coefficient; c ₃ is a second conversion coefficient; c ₅ is a third conversion coefficient; r _kj-2 is the second cross correlation of the k and j channels of the third-order digital correlator to be detected;

wherein,

S _k-2 (n) is a digital sequence of a third analog signal of a k channel of the third-order digital correlator to be detected after third-order quantization; s _j-2 (n) is a digital sequence of the third analog signal of the j channel of the third-order digital correlator to be detected after third-order quantization; n is the number of integration points: n is the noise sequence length;

wherein,

Repeating the above process, inputting each group of third excitation noise signals into the third-order digital correlator to be detected to obtain analog correlation coefficients of a plurality of third-order digital correlators to be detected, and taking u _bias as a standard value, screening and correcting the analog correlation coefficients of the plurality of third-order digital correlators to be detected to obtain the processed analog correlation coefficients; will be And the correlation degree between the processed analog correlation coefficients is used as a third test result.

As one of the improvements of the above technical solution, the specific process of the fourth data sending and processing unit is as follows:

wherein,

S _k-2 (n) is a digital sequence of a third analog signal of a k channel of the third-order digital correlator to be detected after third-order quantization; s _j-2 (n) is a digital sequence of the third analog signal of the j channel of the third-order digital correlator to be detected after third-order quantization; n is the number of integration points:

wherein,

Repeating the above processes, inputting each group of third excitation noise signals into the third-order digital correlator to be detected to obtain analog correlation coefficients of a plurality of third-order digital correlators to be detected, and screening and correcting the analog correlation coefficients of the plurality of third-order digital correlators to be detected to obtain processed analog correlation coefficients; then establishing a rectangular coordinate system to be And forming a point by taking the processed analog correlation coefficient as an ordinate on the abscissa, so as to obtain a plurality of points, measuring the dispersion degree of the data distribution of the plurality of points by combining STD operation, so as to obtain the stability, and taking the stability as a fourth test result.

As one of the improvements of the above technical solution, the specific process of the fifth data sending and processing unit is:

The method comprises the steps that a Labview arbitrary correlation signal generation algorithm is adopted, and a data generation module generates two paths of quantitative (0-360 ℃) Gaussian white noise band-limited signals with phase offset theta as CHi signals and CHj signals;

performing digital-to-analog conversion on the CHi signal and the CHj signal to obtain two paths of fourth noise analog signals, performing digital-to-analog conversion on each path of fourth noise analog signal to obtain corresponding fourth analog signals, performing autocorrelation and cross-correlation operation processing, and performing analog-to-digital conversion to obtain four digital signals of i _i(n)、q_i(n)、i_j (n) and q _j (n):

Calculating the phase of the CHi signal and the CHj signal

Wherein M _ij is a real complex analog correlation coefficient obtained by soft simulation calculation of two groups of fourth excitation noise signals, namely CHi signals and CHj signals of the three-order digital correlator to be detected; The real part of a real complex analog correlation coefficient is obtained by soft simulation calculation of two groups of fourth-order noise signals of a CHi signal and a CHj signal of a third-order digital correlator to be detected; the imaginary part of a real complex analog correlation coefficient is obtained by soft simulation calculation of two groups of fourth excitation noise signals of a CHi signal and a CHj signal of a third-order digital correlator to be detected;

wherein, Analog correlation coefficients of an I path and an I path of two groups of fourth laser noise signals of a CHi signal and a CHj signal of the third-order digital correlator to be detected; the analog correlation coefficients of the Q paths and the Q paths of the two groups of fourth-order noise signals of the CHi signal and the CHj signal of the third-order digital correlator to be detected; analog correlation coefficients of an I path and a Q path of two groups of fourth laser noise signals of a CHi signal and a CHj signal of the third-order digital correlator to be detected; Analog correlation coefficients between the Q path and the I path of two groups of fourth laser noise signals of the CHi signal and the CHj signal of the third-order digital correlator to be detected; i _i (n) is one digital signal in the CHi signal; q _i (n) is another digital signal in the CHi signal; i _j (n) is one digital signal in the CHj signal; q _j (n) is another digital signal in the CHj signal;

Calculation of actual measured phases of CH1 and CH2 signals

Wherein M ¹ _ij is the actually measured complex analog correlation coefficient of two groups of fourth excitation noise signals of CHi signal and CHj signal of the three-order digital correlator to be measured; real parts of actually measured complex analog correlation coefficients of two groups of fourth excitation noise signals, namely CHi signals and CHj signals of the three-order digital correlator to be measured; imaginary parts of actually measured complex analog correlation coefficients of two groups of fourth excitation noise signals of CHi signals and CHj signals of the three-order digital correlator to be measured;

And further determining the relative phase error of the third-order digital correlator to be detected:

And taking the related phase error of the third-order digital correlator to be tested as a fifth test result.

The invention also provides a performance test method for the third-order digital correlator, which comprises the following steps:

the data parameter setting module simultaneously sends setting parameters of the multi-path required excitation noise signals to the data generating module;

the data generation module correspondingly generates a first excitation noise signal, a second excitation noise signal, a third excitation noise signal and a fourth excitation noise signal of any waveform according to the set parameters of the transmitted excitation noise signals;

The data transmitting and processing module respectively carries out digital-to-analog conversion on the first excitation noise signal, the second excitation noise signal, the third excitation noise signal and the fourth excitation noise signal to respectively obtain corresponding noise analog signals, sequentially inputs the corresponding noise analog signals to the third-order digital correlator to be tested, tests the related bias performance, the related efficiency performance, the stability performance, the linearity performance and the phase error performance of the third-order digital correlator to be tested to obtain corresponding test results, and completes the performance test of the third-order digital correlator.

Compared with the prior art, the invention has the beneficial effects that:

1. In the application, the system full link is realized automatically, the excitation signal simulation module and the data analysis module are realized by using the same control console, and the test efficiency can be improved by generating excitation noise to perform a test experiment and performing data analysis on the test result.

2. The method of the invention uses the multichannel DAC to play the simulation generated excitation signal so as to realize the multichannel simultaneous test of the large-scale digital correlator to be tested.

3. The analysis result of the measured data of the correlator is analyzed by means of the data simulation result, so that the influence of non-ideal characteristics caused by limited test data length on the test result is avoided. The data soft simulation is realized by means of the third-order quantization logic equivalent to the correlator, so that measurement errors caused by probability common non-ideal Gaussian of test data are avoided, and the test precision is improved.

4. Based on Labview signal simulation algorithm, test signals with controllable multipath correlation and linear increment can be quantitatively generated and reused, so that the stability and linearity of the system are tested, the influence of sensitivity on stability test is effectively avoided, and the performance evaluation of the digital correlator is more complete.

Drawings

Fig. 1 is a flow chart of a performance testing method for a third order digital correlator in accordance with the present invention.

Detailed Description

The invention will now be further described with reference to the accompanying drawings.

Specifically, the setting parameters of the excitation noise signal include: correlation coefficient, power, integration time, sampling rate and bandwidth of the noise signal.

specifically, the data generation module includes:

The third excitation signal generation unit is used for correspondingly generating multiple Gaussian white noise band-limited signals with integration duration of 2.4s, correlation coefficient of (0:10 ^-4：5×10^-4) and 100M bandwidth according to the setting parameters of the excitation noise signals sent by the data transmission and processing terminal, and the multiple Gaussian white noise band-limited signals are used as multiple groups of third excitation noise signals; wherein each group of third excitation noise signals comprises two Gaussian white noise band-limited signals; and

And the fourth excitation signal generating unit is used for correspondingly generating two groups of Gaussian white noise band-limited signals CH1 and CH2 with analog correlation coefficients of 0.04+j0.02 as fourth excitation noise signals according to the setting parameters of the excitation noise signals sent by the data transmission and processing terminal.

Specifically, the data sending and processing module comprises: the system comprises a first data transmission and processing unit, a second data transmission and processing unit, a third data transmission and processing unit, a fourth data transmission and processing unit and a fifth data transmission and processing unit;

The first data transmitting and processing unit is used for carrying out digital-to-analog conversion on each Gaussian white noise band-limited signal in each group of first excitation noise signals simultaneously to obtain a plurality of paths of first noise analog signals, inputting the first noise analog signals of each path to the third-order digital correlator to be tested, and testing the related bias performance of the third-order digital correlator to be tested to obtain a plurality of first test results;

Specifically, the specific process of the first data processing unit is as follows:

according to any group of first excitation noise signals, the related bias performance of the third-order digital correlator to be tested is tested and analyzed, and the specific process is as follows:

wherein,

S _k (n) is a digital sequence of the first analog signal of the k channel of the third-order digital correlator to be detected after third-order quantization; s _j (n) is a digital sequence of the first analog signal of the j channel of the third-order digital correlator to be detected after third-order quantization; n is the number of integration points: n is the noise sequence length;

wherein,

wherein, The true analog correlation coefficient obtained by calculation in the third-order digital correlator to be tested is calculated for the group of first excitation noise signals;

taking the related bias of the third-order digital correlator to be tested as a first test result;

In this embodiment, 8 paths of first analog signals with uncorrelated signals are used for arbitrary pairwise combination and input into corresponding optional two channels, so that 26 correlated offsets can be obtained, the precision of each correlated offset is 10 ^-4, and the calculated correlated offset is more accurate and precise, thereby providing data support for subsequent radiometer applications.

The second data sending and processing unit is used for carrying out digital-to-analog conversion on each Gaussian white noise band-limited signal in each group of second excitation noise signals to obtain a plurality of paths of second noise analog signals, inputting the second noise analog signals of each path to the third-order digital correlator to be tested, and testing the correlation efficiency performance of the third-order digital correlator to be tested to obtain a plurality of second test results;

Specifically, according to any group of second excitation noise signals, the correlation efficiency performance of the third-order digital correlator to be tested is tested and analyzed, and the specific process is as follows:

wherein,

and further calculating the correlation efficiency eta of the third-order digital correlator to be tested of the group of second excitation noise signals by using the first test result:

wherein, The real analog correlation coefficient calculated in the third-order digital correlator to be detected for the group of second excitation noise signals, namely the second excitation noise signals are subjected to third-order quantized data soft simulation, and the simulation correlation coefficient calculated by simulation is obtained by utilizing the same principle and is not 0;

taking the correlation efficiency of the third-order digital correlator to be tested as a second test result;

Repeating the above process, inputting each group of second excitation noise signals into the third-order digital correlator to be tested, and performing correlation efficiency test on the third-order digital correlator to be tested to obtain correlation efficiencies of a plurality of third-order digital correlators to be tested, thereby obtaining a plurality of second test results;

The correlation efficiency obtained through the calculation is at least more than 99.7%, so that the corresponding correlation efficiency error is within 0.3%, and the accuracy is greatly improved.

The third data sending and processing unit is used for carrying out digital-to-analog conversion on each Gaussian white noise band-limited signal in each group of third excitation noise signals simultaneously to obtain a plurality of paths of third noise analog signals, inputting the third noise analog signals of each path to the third-order digital correlator to be tested, and testing the linearity performance of the third-order digital correlator to be tested to obtain a third test result;

Specifically, according to any group of third excitation noise signals, the linearity performance of the third-order digital correlator to be tested is tested and analyzed, and the specific process is as follows:

wherein,

The linearity obtained by the calculation is more than or equal to 0.99.

The fourth data sending and processing unit is used for carrying out digital-to-analog conversion on each Gaussian white noise band-limited signal in each group of third excitation noise signals simultaneously to obtain a plurality of paths of third noise analog signals, inputting the third noise analog signals of each path to the third-order digital correlator to be tested, and testing the stability performance of the third-order digital correlator to be tested to obtain a plurality of fourth test results;

wherein,

Through the calculation process, the standard deviation of the obtained analog correlation coefficient is tested, namely the stability is less than or equal to 2.5E-5.

The fifth data transmitting and processing unit is used for carrying out digital-to-analog conversion on each Gaussian white noise band-limited signal in each group of fourth excitation noise signals to obtain a plurality of paths of fourth noise analog signals, inputting the fourth noise analog signals of each path to the third-order digital correlator to be tested, and testing the related phase error performance of the third-order digital correlator to be tested to obtain a plurality of fifth test results;

specifically, a Labview arbitrary correlation signal generation algorithm is adopted, and a data generation module generates two paths of quantitative (0-360 ℃) Gaussian white noise band-limited signals with phase offset theta as CHi signals and CHj signals;

Calculating the phase of the CHi signal and the CHj signal

Calculation of actual measured phases of CH1 and CH2 signals

The phase error obtained by the above calculation is <0.13 °.

Wherein the test system further comprises: and the evaluation analysis module is used for respectively evaluating and analyzing the related bias performance, the related efficiency performance, the stability performance, the linearity performance and the phase error performance of the third-order digital correlator to be tested according to the obtained test result.

Specifically, according to the existing test standard for testing the related bias performance, the accuracy of each related bias in the obtained first test result is 10 ^-4, and the related bias performance of the third-order digital correlator to be tested is estimated to be optimal by exceeding the test standard;

according to the existing test standard for testing the related efficiency performance, using the obtained second test result that each related efficiency is more than 99.7%, and the related efficiency error is less than 0.3%, and evaluating the related efficiency performance of the third-order digital correlator to be tested to be optimal when the related efficiency error exceeds the test standard;

According to the existing test standard of the linear degree performance test, the correlation degree of each analog correlation coefficient and the analog correlation coefficient of the soft simulation in the obtained third test result is more than 0.99, and the linear degree performance of the third-order digital correlator to be tested is estimated to be optimal by exceeding the test standard;

According to the existing test standard for testing the related bias performance, evaluating the stability performance of the third-order digital correlator to be tested to be optimal by utilizing each stability in the obtained fourth test result to exceed the test standard;

According to the existing test standard for testing the performance of the related phase error, the related phase error performance of the third-order digital correlator to be tested is estimated to be optimal by utilizing the fact that the phase error in the obtained fifth test result is within 0.13 degrees and exceeds the test standard.

The method further comprises the steps of: and the evaluation analysis module evaluates and analyzes the relevant bias performance, the relevant efficiency performance, the stability performance, the linearity performance and the phase error performance of the third-order digital correlator to be tested according to the obtained test result.

The system provided by the invention is based on a Labview signal simulation algorithm, can quantitatively generate test signals with controllable multipath correlation and linearly increased, and is repeatedly used, so that the stability and the linearity of the system are tested, and the influence of sensitivity on the stability test is effectively avoided.

The method of the invention can avoid the influence of device errors such as an additional amplifier, a power divider and the like on the test result, not only reduces the complexity of the test system, but also corrects the influence of the non-ideal characteristic of the data on the test result, thereby improving the test precision.

Finally, it should be noted that the above embodiments are only for illustrating the technical solution of the present invention and are not limiting. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the present invention, which is intended to be covered by the appended claims.

Claims

1. A performance testing system for a third-order digital correlator, the testing system being disposed on a console and comprising: the device comprises a data parameter setting module, a data generating module and a data transmitting and processing module;

The data transmitting and processing module is used for respectively performing digital-to-analog conversion on the first excitation noise signal, the second excitation noise signal, the third excitation noise signal and the fourth excitation noise signal to respectively obtain corresponding noise analog signals, and sequentially inputting the corresponding noise analog signals to the third-order digital correlator to be tested; testing the related bias performance, the related efficiency performance, the stability performance, the linearity performance and the phase error performance of the third-order digital correlator to be tested to obtain a corresponding test result, and completing the performance test of the third-order digital correlator;

The data transmitting and processing module comprises:

The fifth data transmitting and processing unit is used for performing digital-to-analog conversion on each path of Gaussian white noise band-limited signal in the fourth excitation noise signal to obtain a plurality of paths of fourth noise analog signals, and inputting the fourth noise analog signals of each path of the fourth noise analog signals to a third-order digital correlator to be detected; testing the related phase error performance of the third-order digital correlator to be tested to obtain a fifth test result;

the specific process of the first data sending and processing unit is as follows:

wherein,

Repeating the above process, inputting each group of first excitation noise signals to the third-order digital correlator to be tested, and performing a correlation bias test on the third-order digital correlator to be tested to obtain correlation biases of a plurality of third-order digital correlators to be tested, thereby obtaining a plurality of first test results;

The specific process of the second data sending and processing unit is as follows:

wherein,

The specific process of the third data sending and processing unit is as follows:

wherein,

S _k-2 (n) is a digital sequence of a third analog signal of a k channel of the third-order digital correlator to be detected after third-order quantization; s _j-2 (n) is a digital sequence of the third analog signal of the j channel of the third-order digital correlator to be detected after third-order quantization; n is the number of integration points: n is the length of the noise sequence;

wherein,

Repeating the above process, inputting each group of third excitation noise signals into the third-order digital correlator to be detected to obtain analog correlation coefficients of a plurality of third-order digital correlators to be detected, and taking u _bias as a standard value, screening and correcting the analog correlation coefficients of the plurality of third-order digital correlators to be detected to obtain the processed analog correlation coefficients; will be And the correlation degree between the processed analog correlation coefficients is used as a third test result;

the specific process of the fourth data sending and processing unit is as follows:

wherein,

Repeating the above processes, inputting each group of third excitation noise signals into the third-order digital correlator to be detected to obtain analog correlation coefficients of a plurality of third-order digital correlators to be detected, and screening and correcting the analog correlation coefficients of the plurality of third-order digital correlators to be detected to obtain processed analog correlation coefficients; then establishing a rectangular coordinate system to be Forming a point by taking the processed analog correlation coefficient as an ordinate on the abscissa, so as to obtain a plurality of points, measuring the dispersion degree of data distribution of the plurality of points by combining STD operation, so as to obtain stability, and taking the stability as a fourth test result;

The specific process of the fifth data sending and processing unit is as follows:

Calculating the phase of the CHi signal and the CHj signal

Calculation of actual measured phases of CH1 and CH2 signals

Wherein,

2. The performance testing system for a third-order digital correlator according to claim 1 wherein the testing system further comprises: and the evaluation analysis module is used for respectively evaluating and analyzing the related bias performance, the related efficiency performance, the stability performance, the linearity performance and the phase error performance of the third-order digital correlator to be tested according to the obtained test result.

3. The performance testing system for a third-order digital correlator according to claim 1 wherein the data generation module comprises:

4. A performance testing method for a third-order digital correlator, the method being implemented on the basis of the performance testing system for a third-order digital correlator as claimed in any one of claims 1 to 3, the method comprising: