This paper presented a general systematic view , application and current development of the power line carrier transmission technology , and clearly compared some existing power line carrier communication chip with each other . then the authors analyze the channel " s characters of low voltage power line , and formed an abstract carrier channel model . using this as its basis , a new kind of transmission technology is designed that adopted transmission technology combining the spread spectrum modulation with channel coding , which can solve the problems above mentioned to a certain degree , and need not pay for high cost 文章不仅全面地介绍了电力线载波通讯技术的特点、应用及其发展状况，还对目前的电力线载波通讯芯片进行了比较；并通过对低压电网信道特性的分析和研究，抽象出其载波信道模型，在此基础上，提出了将扩频调制和信道编码相结合的传输技术用于低压电力线载波通信，这可以在很大程度上解决电力线的干扰问题，且不必付出高昂的代价。
This chapter is a base of next chapter . mathematics theory and pseudo stochastic code theory for spread spectrum modulation sequence are introduced , and simulink experiment and analysis about correlation performance of the most common use spectrum modulation sequence are processed , these experiment contact to performance parameters of the spread spectrum sequence . the correlation performance and address quantity are compared between m sequence and gold sequence 本章是第五章的理论基础，介绍了扩频调制序列的数理基础和伪随机码理论，同时联系调制序列的性能指标对最常用的两种扩频调制序列的相关性能进行了仿真研究和分析讨论，比较了m序列和gold序列互相关特性和地址数。
