【摘要】 为了解决软件无线电通信系统中频采样之后的极大数据量,在基带处理部分对DSP的计算压力,其接收机中采用了数字下变频技术。笔者重点研究数字下变频技术中的降采样率问题,对降采样率技术的单级整倍数和多级整倍数抽取实现方案进行了详细的分析对比,并利用MATLAB完成了仿真分析。仿真结果表明:同等技术指标下应优先考虑多级二倍数抽取,其次考虑多级整倍数抽取,尽量不使用单级整倍数抽取方案。该结论对如何选择合适的降采样技术实现方案,在实际应用中具有指导意义。更多还原

【Abstract】 Directed at increasing data due to intermediate frequency sampling in software defined radio system,the paper introduces the use of the technique of digital down-converter in the receiver to reduce the DSP computation press of the baseband.This paper is focused on reducing sampling frequency in digital down-converter technique,analyzing the scheme of single level of integral multiple decimation technique and multilevel of integral multiple decimation technique,and performing the simulation analysis with MATLAB.The simulation result shows the necessity of using multilevel of duple decimation technique firstly in the same technique target and multilevel of integral multiple decimation technique is the second selection.Single level of integral multiple decimation technique is not used unless you have no other ways.The study concludes that it is important to guide how to select the best scheme of reducing sampling frequency technique in practice.更多还原