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研究了双基地多载频MIMO雷达中由ADC采样引起的同步误差的3种提取方法。首先建立了同步误差的信号模型,仿真分析了同步误差对测距以及测角的影响,并将其归结为高精度频率估计问题。频谱连续细化法在较小范围内利用连续傅里叶变换来获得高精度的频率估计,既可以降低运算量又能获得较高的频域分辨率;自相关函数法通过对通道分离并补偿阵列延时差后的直达波信号的自相关函数做反正切运算求得同步误差值;MUSIC法首先构造时间同步误差的导向矢量,并利用其向噪声子空间投影,通过搜索空间谱的最大值来得到同步误差值。最后仿真比较了3种方法的性能,结果表明在低信噪比时可采用运算量较大的MUSIC法以取得较好的性能,而在信噪比较高时可采用运算量较小的自相关函数法或者频谱细化法以获得较快的处理速度。
Three kinds of extraction methods of synchronization error caused by ADC sampling in bistatic multi-carrier frequency MIMO radar are studied. Firstly, the signal model of synchronization error is established. The influence of synchronization error on distance measurement and angle measurement is simulated and analyzed, which is attributed to the problem of high-precision frequency estimation. The continuous spectrum refinement method uses continuous Fourier transform to obtain high-precision frequency estimation in a small area, which not only reduces the computation complexity but also obtains higher resolution in the frequency domain. The autocorrelation function method separates and compensates the channel Array autotranslation function of the delayed wave signal to do the arctangent operation to obtain the synchronization error value; MUSIC method first construct the time synchronization error of the steering vector, and use it to the projection of the noise subspace, through the search space spectrum maximum To get the synchronization error value. The final simulation compares the performance of the three methods. The results show that the MUSIC method can be used to obtain better performance at low signal-to-noise ratio, while the higher signal-to-noise ratio Correlation function method or spectrum thinning method to get faster processing speed.