双频段信号的带通采样频率选取方法

A Method of Selecting the Valid Bandpass Sampling Rate for Dual-band signals

本文针对软件无线电(SDR)系统中双频段信号的带通采样问题,提出了一种基于中频带通采样架构的采样频率选取方法。该方法结合中频频率的选取,给出了有效采样频率范围和最小采样频率的求解算法,且考虑到了采样后频谱之间的保护带宽。与其他方法相比,该方法不但兼顾了模数转换器(ADC)的模拟输入带宽,并且在保证频谱不发生倒置的前提下,得到较低的采样频率。仿真与实验结果表明,该采样频率选取方法理论可行,具有很好的工程可实现性。

In this paper,an efficient method of selecting the valid sampling rate for dual-band signals is proposed,which is based on the direct intermediate frequency sampling in software defined radio（SDR）systems.According to the value of the intermediate frequency,the method provides an algorithm to search the valid range of sampling rates and the minimum sampling frequency.The guard-bands between the down converted signal spectra are also analyzed in the algorithm.Compared with other methods,the proposed method not only considers the analog input bandwidth of the ADC,but also obtains a lower sampling frequency when the spectrum inversions are avoided.Simulation and experimental results show that this method is feasible and has good engineering feasibility.