中频采样全数字接收机的设计与实现

摘要

In this paper, a design of all digital receiver based on software defined radio is presented. The signal is sampled on intermediate frequency in the receiver. The paper introduces the key technologies of this receiver such as band-pass sampling theorem, digital down-conversion and demodulation. The structure of multiple steps of filtering and decimation is adopted in DDC, and the detailed implementation of CIC, HB and FIR is given. The design is used in a FPGA platform with a CPCI bus interface. Demodulation of MPSK and 16QAM is achieved. The system has good extensibility and flexibility.%根据侦察接收机的需要,基于软件无线电理论提出了一种中频采样全数字接收机的设计方案,对其中的带通采样单元、数字下变频单元和解调单元进行了分析。数字下变频采用高效滤波抽取方案,对CIC、HB和FIR滤波器的设计进行了详细介绍。最后在基于FPGA的CPCI接口信号处理平台上进行了实现,完成了多种信号的解调处理,系统具有高度的灵活性和可扩展空间。