基于WFFT/FFT-DWT并行处理提高MTD检测性能的新方法

A WFFT/FFT-DWT Parallel Processing Approach for MTD Detectability Improvement

MTD雷达的多普勒滤波器组常用FFT或加权FFT(WFFT)来实现。当回波的输入信号未被加权 ,且其频率恰好等于FFT滤波器组的某一中心频率时 ,称为匹配状态 ,其输出信噪比最大 ,检测性能最好。针对雷达常常工作于失配状态 ,文献 [1]介绍了一种利用离散小波变换 (DWT)补偿信噪比损失的方法 ,但这种方法仅在频率偏移比较大时才有效。提出了一种基于WFFT与FFT -DWT并行处理的新方法 ,该方法能在整个频率范围内获得优异的检测性能。

The fast Fourier transform (FFT) or weighted FFT is the most common implementation of Doppler filter banks in MTD. When the echo signal is unweighted, and the input frequency is just equal to an FFT bin frequency, the matched state is reached, the output SNR takes the maximum and the detectability is optimal. Consindering the practical case that radars usually work in unmatched state, reference [1] introduces a discrete wavelet transform (DWT) based on the method to compensate the SNR loss. But it is effective only when the frenquency shift is larger. A novel appproch, called the parallel processing of WFFT&FFT-DWT is presented. The result shows that the high detectability in the whole frequency range can be got by the new method.\;