中频数字正交解调接收机的研究及实现

Research and implementation of IF digital quadrature demodulation receiver

数字接收机在现代雷达、电子战、通信等领域的应用越来越广泛,数字接收机的性能是由正交解调信号的幅相一致性决定的。这里描述了数字正交解调的核心部分—数字滤波器的设计,通过运用均方误差最小化准则设计法和切比雪夫等波纹逼近设计法设计FIR数字滤波器,并利用MATLAB平台进行仿真,比较分析表明了用均方误差最小化准则设计法设计具有严格线性相位特性的FIR数字滤波器的最优性,即:可以获得较好的幅度误差和相位误差,从而保证了数字接收机的性能。

Application of digital receiver is more and more widely in modern radar, electronic warfare, communications and other fields,digital receiver performance is decided by the signal from the quadrature amplitude and phase demodulation. This paper describes the core part of the digital quadrature demodulation—digital filter design, by comparing the use of MSE minimization design method and chebyshev equality ripple approach method for FIR digital filter design, and use MATLAB simulation platform found, the optimality of the use of MSE minimization design method design a strict linear phase characteristics of FIR digital filter, which can get a better Amplitude error and phase error, and ensure the performance of the digital receiver.