中频数字正交解调参数的优化设计

微波遥感数据处理中往往要对接收的回波信号在中频直接进行正交解调,以采样定理为基础,通过对遥感器接收到的回波线性调频信号的数字频谱分析和对数字滤波器的性能分析,得出正交解调运算量与回波信号采样率以及低通滤波器阶数的关系。针对某一带宽的信号,设计出对应于不同采样率的解调滤波器,对其性能和运算量作了分析对比并得出最佳设计。

Optimal Design for Parameter of Digital Quadrature Demodulation at Intermediate Frequency

The echo data received in microwave remote sensor is always need to be Quadrature demodulated at intermediate frequency.Based on Nyquist sampling theory,the spectrum of LFM echo received by radar and the performance of digital filter are analysised in the Quadrature demodulation processing,the function of the Computational amount with Fs for received signal and the taps of quadrature sampling filter are educed.Aiming at a group of signals with different bandwidths,a series of filters corresponding to different Fs are designed,the performance and the computational amount are compared in order to get the optimal design.