Matlab维特比译码算法在不同信道中的性能仿真研究
毕业论文关键词: MATLAB；信道编码；卷积码；文特比译码；二进制对称信道；加性高斯白噪声信道
Viterbi decoding algorithm performance simulation based on different channels
Abstract:This paper introduces a digital communication system convolutional codes Viterbi decoding algorithm software implementation to achieve the convolutional code Viterbi decoding functions in Matlab environment. First introduced the significance of digital communication systems, the development of convolution codes and the subject. Then introduced channel coding theory, the principle of encoding and decoding and channel convolutional codes, select three different convolutional code generating polynomial is determined, and a convolutional encoder. Elaborated convolutional codes Viterbi decoding algorithm, and the key parameters that affect the performance of a detailed analysis. Finally, focus on the Viterbi algorithm in the performance characteristics of different channels, and at different bit rates and judgments way, with the matlab simulation study. Simulation results show that the channel, the decision on the mode and rate of impact than the Viterbi decoding algorithm. Meanwhile, after a plurality of sets of data comparison, under the same conditions as the bit error rate, compared to the soft decision Viterbi algorithm with the hard decision Viterbi algorithm coding gain of about 2dB.
Keywords: Channel coding ; Convolution code ; Viterbi decoding ; Binary symmetric channel ; Additive white Gaussian noise channel
目录
1.绪论 1
1.1数字通信系统模型 1
1.2卷积码的发展 2
1.3课题意义 3
2.信道编码 4
2.1信道编码研究背景 4
2.2信道编码基本原理 4
2.3信道编码定理 5
2.4线性分组码 5
2.5循环码 6
2.6卷积码 6
3.卷积码编译码原理 8
3.1卷积码基本理论 8
3.2卷积码编码原理 8
3.3卷积码的代数结构 10
3.3.1卷积码的构成 10
3.3.2系统码形式的卷积码 12
3.3.3卷积码的矩阵描述 13
3.3.4卷积码的图描述 16
3.4文特比译码的度量 18
3.5文特比译码的基本原理 19
3.6卷积码 - Viterbi 译码流程 21
3.7文特比译码的性能 22
4.信道 24
4.1二进制对称信道 24
4.2加性高斯白噪声信道 25
5.基于Matlab的文特比译码性能仿真 28
5.1 卷积编码器设计 28
5.2 文特比译码器模块 32
5.3 文特比译码在二进制对称信道中的性能仿真 34