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应用科学学报 ›› 2004, Vol. 22 ›› Issue (4): 463-466.

• 论文 • 上一篇    下一篇

软件无线电卫星便携地面站中的直接数字频率合成器

漆庄平, 李国通, 杨根庆   

  1. 中国科学院上海微系统与信息技术研究所 上海 200050
  • 收稿日期:2003-08-16 修回日期:2003-10-16 出版日期:2004-12-31 发布日期:2004-12-31
  • 作者简介:漆庄平(1977-),男,江西宜丰人,博士生.

DDFS in a SDR Portable Satellite-Earth Station

QI Zhuang-ping, LI Guo-tong, YANG Gen-qing   

  1. Shanghai Institute of Microsystem and Information Technology, Chinese Academic of Science, Shanghai 200050, China
  • Received:2003-08-16 Revised:2003-10-16 Online:2004-12-31 Published:2004-12-31

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摘要： 理想的软件无线电需要高效且高速的数字下变频器.通常数字下变频采用查找表方法实现,即输入信号的采样乘上一个预先存储在ROM中的正弦余弦函数值.为了得到高精度,这种方法需要很大的查找表,这就意味着占用芯片面积大、功耗大、工作速度低和增加成本.文中描述了一个基于CORDIC算法的直接数字频率合成器.它能大幅度地减少查找表的大小,从而达到高精度的要求.

关键词: 无杂散动态范围, 协调旋转数字计算, 基站, 数字频率合成器

Abstract: An ideal software radio needs efficient high speed digital down converters. The common approach for digital down conversion (DDC) is the so-called ROM table approach where the samples of the input signal are multiplied with amplitude values of the sine-and cosine-function stored in ROM. To achieve high resolution, this technique requires a large look-up table which means large chip area, high power consumption, lower speed, and increased costs.In this paper, a CORDIC-based direct digital frequency synthesizer is described. It is able to reduce the size of the look-up table considerably.

Key words: CORDIC, earth station, DDFS, SFDR

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