一种基于多相结构的高效数字下变频设计  

An efficient digital down converter based on multiphase structure

作　　者：段国栋 蒋小平[1] 马速良[1] 李娜[1] 

机构地区：[1]中国矿业大学(北京)机电与信息工程学院,北京100083

出　　处：《电子技术应用》2014年第4期52-55,共4页Application of Electronic Technique

摘　　要：基于带通采样结构的数字下变频技术是软件无线电收发机的关键技术之一。介绍了一种基于多相结构的带通采样数字下变频设计。首先,采用带通采样,使得ADC更靠近天线,数字化更为充分;其次,通过对采样频率和中频的选取,使得正交混频无需使用查找表,避免了截位处理,改善了混频后的无杂散动态范围;最后,根据并行混频的结构,选择多相抽取滤波器结构进行处理,在确保达到系统要求的同时,提高了硬件资源利用率。该系统具有高度的灵活性和充分的数字化特点,有较高的实用价值。DDC technology based on band-pass sampling is a key of software defined radio receiver. This paper describes a method of DDC design based on band-pass sampling. First of all, band-pass sampling method is provided in this paper, in which the ADC is moved closer to the antenna. This allows more functionality to be defined by software. Secondly, through the selection of the sampling frequency and intermediate frequency,the design allows the FPGA to produce baseband in-phase （I） and quadrature （Q） signals without the use of multipliers or lookup tables, improving the SFDR after mixing. Finally, based on the front structure, polyphase decimation filter is selected in this paper, which ensures meeting the system requirements, improving hardware utilization at the same time. System designed in this article is highly flexible and full digitization. This design has high practical value.

关 键 词：带通采样 数字下变频 多相滤波器 FPGA 

分 类 号：TN99[电子电信—信号与信息处理]