采用DSP TMS320C25设计高速话带数字调制解调器

IMPLEMENTATION OF HIGH SPEED VOICEBAND DATA MODEM USING DSP TMS320C25

阐述了采用数字信号处理（ＤＳＰ）技术实现可编程高速话带调制解调器（ＭＯＤＥＭ）的设计原理和实现方案．提出了适合ＤＳＰ实现的程序结构和算法，调制解调器的编码、数字滤波、调制解调、自适应均衡、载波及定时恢复等主要功能均以编程实现．在用Ｃ语言进行方案模拟和系统优化的基础上，采用通用数字信号处理器ＴＭＳ３２０Ｃ２５实现了全数字９６００ｂｉｔ／ｓ调制解调器，其性能达到了ＣＣＩＴＴＶ．

This paper describes the theory and implementation of a programmable high speed voiceband MODEM on DSP, and puts forward a proper program structure and algorithms for DSP. The main functions of the MODEM such as coding, digital filtering, modulation and demodulation, adaptive equalization, carrier and timing recovery are fully realised by software. Basing on the scheme simulation and system optimization in Turbo C, we realize the all digital 9 600 bit/s MODEM by DSP TMS320C25, its performances satisfy CCITT V.29.