软件无线电数字中频处理的优化设计

软件无线电是目前通信领域研究的热点,其关键技术之一数字中频技术是多速率信号处理理论的典型应用。本文研究了窄带信号条件下,高倍抽取的数字下变频设计,重点分析了基于CIC滤波器和HB滤波器的多级抽取算法。经比较,该设计比单级多相抽取设计节省98.8％的资源,完全可在单片FPGA内实现,而且,滤波性能优于设计指标要求。

Optimal Design of Digital IF in Software Radio

Software Radio has become the focus of research in Communications. Digital IF, one of its key technologies, is typical application of multi-rate signal processing theory. This paper studies high decimation ratio of digital downconverter given narrow-band signal, and especially analyze mul?stage decimation algorithm based on CIC filter and HB filter. By comparison, the optimal design can save 98.8% of the logic resources than that of single stage polyphase design, and can be well implemented in a single FPGA chip. Furthermore, the filtering performance is better than design requirements.