无线电工程

针对扩频系统的载波同步,研究了数字Costas环的设计和实现方法。介绍了数字Costas环的结构、实现载波同步的基本方法。以二阶环为例,分析了数字锁相环的环路滤波器的参数设计方法,为数字Costas环的设计提供了参考。提出了在高速信号处理板(以FPGA和DSP为基础)中数字Costas环的实现方案,经工程验证,能够实现载波同步,解调出所需信号。

The paper introduces the design and implementation of digital Costas-loop for realization of carrier-synchronization in spread spectrum system,and presents its structure as well as the basic method of realizing carrier synchronization.The paper,with second-order loop taken as example,analyzes the parameter design of loop filter of Digital Phase Locked Loop,which provides a reference for the design of digital Costas-loop.The implementation scheme of digital Costas-loop in high-speed digital signal board(based on FPGA and DSP) is presented,and it is proven by engineering validation that the Costas-loop can realize carrier synchronization and demodulate the needed signal.