水声系统中的优化均衡技术研究

摘要

Aiming at the problems of the characteristics of low transmission frequency and rate,limited bandwidth and strong multi-path effect in underwater acoustic comrunication,optimal equalization technology in underwater acoustic system is designed.It combines LDPC code,direct-sequence spread spectrum and DQPSK.And LDPC-DQPSK based on soft decision decoding is a method to overcome high error rate performance of traditional hard decision.LMS and RLS algorithm are investigated,analysing the system BER performance of different adaptive equalization scheme based on the characteristics of underwater acoustic channel.Experimental results show that the proposed underwater acoustic system can obtain improved error rate in lower SNR,saving the transmission bandwidth.%针对水声通信系统传输频率低、速率慢、带宽受限且多径干扰严重等问题,设计一种水声系统优化均衡技术.将LDPC码、直接序列扩频和DQPSK技术相结合,采用LDPC-DQPSK软判决译码方案克服传统硬判决误码率高的缺陷,并依据水声信道的特点,研究LMS算法和RLS算法在不同方案下的系统误码率性能.实验结果证明,该技术能够在较低的信噪比条件下改善系统误码率,节省传输带宽.