低码率信道编码后加扰的码分多址特性分析  

Analysis on CDMA Characteristic of Scrambled Transmission after Low Bit Rate Channel Coding

作　　者：石荣 宋庆军 SHI Rong;SONG Qingjun(Science and Technology on Electronic Information Control Laboratory,Chengdu 610036,China)

机构地区：[1]电子信息控制重点实验室,四川成都610036

出　　处：《无线电通信技术》2022年第5期851-856,共6页Radio Communications Technology

基　　金：中国电科技术创新基金项目。

摘　　要：在现代通信系统中广泛采用扰码来增强码流的随机性,从而实现符号定时的恢复与信息保密传输的功能。除此之外,多个用户使用相同的信道编码器实施低码率信道编码之后,采用不同的扰码序列进行加扰,能够达到多用户同时同频通信传输的目的。对于这种码分多址传输方法,分别从硬比特编码空间与软比特解码空间对相关技术原理进行了分析,并采用重复码加扰模型重新解释了传统直接序列扩频通信的码分多址特性,从而构建了一个码分多址通信传输的统一框架模型。最后通过仿真验证了理论分析的正确性与有效性,从而为码分多址通信系统的理论建模与特性分析提供了新参考。The scrambling code is widely used in modern communication systems to enhance the randomness of code stream,so as to realize the functions of symbol timing recovery and safe information transmission.In addition,after multiple users use the same channel encoder to implement low bit rate channel coding,they use different code sequences for scrambling,which can achieve the purpose of multi-user simultaneous and same frequency communication.For this type of Code Division Multiple Access(CDMA)transmission method,the relevant technique principles are analyzed from hard bit coding space and soft bit decoding space respectively.Then the repeated code scrambling model is used to explain the CDMA characteristics in traditional direct sequence spread spectrum communication once again,so as to construct a unified framework model for CDMA communication.Finally,the correctness and effectiveness of the theoretical analysis are verified by simulations.It provides a new reference for the theoretical modeling and characteristic analysis of CDMA communication system.

关 键 词：低码率信道编码 加扰与解扰 码分多址 软比特解扰 直接序列扩频 重复码加扰 

分 类 号：TN911[电子电信—通信与信息系统]