CORDIC算法在跟踪环中的应用与FPGA实现

摘要

CORDIC algorithm is used for tracking loop discriminatois, including the discriminator in code tracking loop, phase-lock loop and frequency-lock loop, and conducted FPGA implementation.In the design, an unified CORDIC algorithm is used to reduce hardware resources, and the three tracking loop discriminators ane implemented by using a non-pipelined basic unit of CORDIC calcula-tion. Good performance of loop discriminators is achieved with analyzing the precision and bit-width of CORDIC calculation unit and the hardware resources are minimized. A satisfactory tracking perfor-mance is obtained according testing loop discriminators in a GPS tracking loop on Virtex5 lx220.%主要介绍了CORDIC算法在跟踪环鉴别器中的应用，包括码跟踪环、锁频环和锁相环鉴别器，并进行了FPGA实现。在设计中，采用统一CORDIC算法优化方法减少硬件开销，用非流水方式在一个CORDIC运算基本单元中实现了码跟踪环、锁频环和锁相环三种鉴别器。同时对CORDIC运算的精度和位宽进行分析，在保证环路功能的情况下尽量减少硬件资源的使用。在Virtex5 lx220上测试使用了该鉴别器的GPS跟踪环，取得了满意的跟踪效果。