摘要：卷积码是一种性能非常优越的信道编码。卷积码的编码器和译码器都比较容易实现，而且它具有较强的纠错能力。随着纠错编码的理论研究不断深入，卷积码的实际应用也越来越广泛。仿真过程利用MATLAB和Simulink模块完成对卷积码的编码和译码的实现，以及误比特统计整个过程的仿真结果。通过对卷积码在不同信道中传输的性能来验证是否用于可靠的信息传输，在仿真过程中分别改变卷积码的主要参数来加深理解卷积码的这些参数对卷积码的误码性能的影响。通过仿真和实测，并对测试结果作了分析。62139

毕业论文关键字：卷积码、MATLAB、Viterbi译码、误比特率

Convolution code performance simulation based on MATLAB

Abstract：Convolutional code is a kind of channel code with excellent performance. Its encoder and decoder are relatively easy to implement, and it has a strong error correction capability. With the continuous deepening of the theory of error correction coding, the practical application of convolutional codes is more and more widely. This paper briefly introduces the coding principle of convolutional codes and the principle of Viterbi decoding. And in the design of Simulink module, the coding and decoding of convolutional codes and the simulation of the whole process of bit error statistics are completed. Through the performance of the convolutional codes in different channel transmission to verify whether it is used for reliable message transmission, in the simulation process were changed convolutional codes is an important parameter to enhance mutual understanding of convolution code these parameters influence on BER performance of convolutional codes. After simulation and test, the test results are analyzed.

Key words: convolution code, MATLAB, Viterbi decoding, bit error rate

目录

摘要 2

1 引言 2

2 基本原理 4

2.1 通信系统和信道编码基本原理 4

2.1.1 通信系统 4

2.1.2 信道编码 4

2.2 卷积码基本原理 5

2.2.1卷积码编码 5

2.2.2卷积码译码 6

2.2.3 卷积码编码器和维特比译码器 8

2.3 软判决和硬判决 10

2.4 信道 11

2.4.1 加性高斯白噪声信道 12

2.4.2 瑞利衰落信道 13

2.4.3 莱斯信道 14

2.4.4 二进制对称信道 16

3 基于MATLAB的卷积码编译码仿真 17

3.1卷积码不同码率对误比特率的影响 17

3.1.1 Simulink仿真框图 17

3.1.2 运行的程序和仿真结果 22

3.1.3 仿真结果分析 23

3.2不同的多项式对卷积码误码率的影响 23

3.2.1 Simulink仿真框图 24

3.2.2 运行的程序和仿真结果 25

3.2.3 仿真结果分析 27

3.3不同信道对Viterbi译码性能的影响 27

3.3.1 二进制平衡信道中的仿真