压缩查找表的高精度CORDIC算法设计  

Design of a High-Precision CORDIC Algorithm with Compressed Look-up Table

作　　者：姚亚峰[1] 邹凌志 侯强[1] 钟梁 YAO Yafeng;ZOU Lingzhi;HOU Qiang;ZHONG Liang(Faculty of Mechanical and Electronic Information,China University of Geosciences,Wuhan 430074,Hubei,China)

机构地区：[1]中国地质大学(武汉)机械与电子信息学院,湖北武汉430074

出　　处：《华南理工大学学报（自然科学版）》2018年第10期58-62,71,共6页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(61601334);中国地质大学中央高校军民融合专项基金培育项目(201708)~~

摘　　要：目前16位精度的坐标旋转数字计算机(CORDIC)算法设计存在输出时延长、硬件消耗大等问题,而在数字加密和信息安全等领域需要32位乃至更高精度的输出.文中提出了一种基于压缩查找表的32位精度CORDIC算法,根据内在迭代规律分解并压缩查找表,还采用区间折叠、角度重编码和合并迭代等,实现了一种电路资源消耗不大,输出时延仅需3个时钟周期,基于定点数格式的算法设计.仿真结果表明,查找表容量压缩到常规方法所需容量的1. 78%,输出时延从常规方法所需的8个时钟周期降低至3个时钟周期,输出平均误差为2. 3048×10-10.本设计具有电路资源消耗少、精度高、输出时延低等优点,更适合实时性强、硬件资源紧凑的现代通信应用场合.Currently algorithm implementation for 16-bit CORDIC has some drawbacks such as long output delay and huge hardware consumption,yet 32-bit or higher precision outputs are needed in areas like digital encryption and information security.The 32-bit CORDIC algorithm,with a compressed LUT(look-up table),was proposed in this paper.The improved design,with less circuit resources and 3 clock period output delay,compressed and decomposed the LUT according to the inner iteration pattern,folded the range,re-coded the angle,and merged some iterations.Simulation indicates that the size of compressed LUTusing fixed-point format is reduced to 1.78%,and the output delay periods are reduced from 8 to 3.Moreover,the average of magnitude of output error is 2.304 8×10-10.The improved design has some advantages such as less hardware consumption,higher precision and less output delay,and it is more applicable for modern communication occasions that demand for brilliant time-real performance and less hardware resources.

关 键 词：坐标旋转数字计算机 压缩查找表 角度重编码 定点数 

分 类 号：TN492[电子电信—微电子学与固体电子学]