文档介绍：摘要
在数字通信系统中,通常采用差错控制编码来提高系统的可靠性。,这一编码技术至今仍显示出强大的生命力。目前,卷积码已广泛应用在无线通信标准中,如GSM,CDMA2000和IS-95等无线通信标准中。
针对N-CDMA数据传输过程中的误码问题,本文论述了旨在提高数据传输质量的维特比译码器的设计。虽然Viterbi译码复杂度较大,实现较为困难,但效率高,速度快。
因此本文着重分析和讨论了1/2速率的(2,1,9)卷积码编码和其Viterbi译码算法。深入研究卷积码编码原理和Viterbi算法原理后,提出了(2,1,9)卷积码编码以及Viterbi算法的初始化、加—比—选和回溯设计方案,运用查表的方法,避免了大量繁琐计算,使得译码简洁迅速,译码器的实时性能良好。并充分利用TMS320C54X系列DSP芯片,用汇编语言完成了(2,1,9)卷积码编码和Viterbi译码的程序。
关键词:差错控制编码、卷积码、Viterbi译码、TMS320C54X、DSP
Abstract
In munication systems, error control coding is usually used to improve system reliability. Since put forward the convolutional coding the first time, the coding is still showing strong vitality.,has e widely used in munications, munications and many munication systemsas a kind of channel coding method. such as GSM, CDMA2000 and has been a munication standards of IS-95.
In view of the error problem in the process of N-CDMA data transmission, this paper discusses the aims to improve the quality of data transmission of victor design than the decoder.
Although Viterbi plexity is bigger, more difficult to achieve, but high efficiency and fast speed. So this article emphatically analyzed and discussed the 1/2 rate (2,1,9) convolution code coding and its Viterbi decoding algorithm. In-depth study on principle of convolution code coding and Viterbi algorithm, proposed the convolution code coding and Viterbi algorithm (2,1,9) initialization, add - than - choose and back design, using look-up table method, to avoid a large amount of tedious calculation, the decoding and quick, good real-time performance of the decoder. Make full use of the series of TMS320C54X DSP chip, using assembly language plete the(2,1,9)convolution code coding and Viterbi decoding process.
Keywords: error control coding, convolutional code, Viterbi decoding, TMS320C54X
目录
摘要 1
Abstract 2
目录 3
1
移动通信及N-CDMA背景 1
数字通信概述 1
卷积编码与译码的发展 3
主要研究工作 3
5
DSP概述 5
DSP的主要特点 5
CSSU单元概述 7
8