基于多相滤波的高效数字下变频设计

An Efficient Digital Down Converter Based on Poly-phase Filter

航天测控系统中,随着对抗干扰能力、测量精度要求的提高,信号带宽已由几十兆赫兹发展到百兆赫兹量级甚至更高,此时采用传统的方式完成数字下变频已经不再可行。分析了一种基于多相滤波结构的数字下变频方法,并通过FPGA实现验证了在低频下完成高速数据流下变频是现实可行的。从占用FPGA资源对比证明了提出的方法相对于传统下变频法有较大的优越性。

Requirement of Space TTC system on anti-interference ability and precision keeps raising. Signal bandwidth has evolved from tens of megahertz to hundreds of megahertz or higher. In this case,traditional digital down conversion is no longer feasible.This paper analyzes a digital frequency down conversion based on poly-phase filtering structure. FPGA implementation verified that it is feasible to complete high speed data stream conversion at low frequency. Finally,comparison of FPGA resource consumption proved that the method proposed in this paper is superior to the traditional frequency conversion method.