由十其强人的功能而被广泛应{IJ十很多工程领域。在扩频通信，}，通常的做法是{IJ扩频序列J信号和乘， 从而得到频谱的扩展或扭缩，因而扩频序列的性能直接决定着通信质量。伪随机序列，}，的m序列和Cold序列最常{}J们一扩 频序列。该文首先简中介绍了m序列和Cold序列的原理、性能和构造方法.接着在MAfLAB }}})IJ M语言编程实现它们的产 生和分析。仿真结果验证了该方法的正确性和可行性。该方法简练直观，适合工程技术人员参考。

Flexible construction of girth-six QC-LDPC Codes-The program constructs girth-six QC-LDPC codes given row-weight,k, column-weight,j, and sub-matrix size,m. The obtained parity-check matrix is stored in H. The construction has flexibility in that j,k

Construct the short length of QC LDPC codes without girth 4 and girth 6-The Program to construct the short length of QC LDPC codes without girth 4 and girth 6 Copyright (C) Yang XIAO, Jun FAN, BJTU, July 26, 2007, E-Mail: yxiao@bjtu.edu.cn.

基于CDMA扩频通信技术的仿真，采用的调制方法是GMSK调制，模拟信道噪声，输出信噪比，说明CDMA扩频通信的抗噪性- 58/5000 Jīyú CDMA kuò pín tōngxìn jìshù de fǎngzhēn, cǎiyòng de tiáozhì fāngfǎ shì GMSK tiáozhì, mónǐ xìndào zàoshēng, shūchū xìn zào bǐ, shuōmíng CDMA kuò pín tōngxìn de kàng zào xìng