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1.前言 1977年,Cooper和Nettleton发表了采用跳频(FH)的扩频(SS)移动通信系统,指出每单位区域内可同时通信的用户数比调频制增加2～5倍。这一成果的发表引起了极大的轰动,1978年度的CCIR(国际无线电咨询委员会)大会采纳了促进扩频研究的要求。而Henry又指出,每单位区域可用的平均信道数反而下降到调频制的一半。从此,对扩频移动通信的研究日益活跃。对扩频的研究虽是最近才引人注目,但其起源却在四
1. Introduction In 1977 Cooper and Nettleton published a spread spectrum (SS) mobile communication system using Frequency Hopping (FH), indicating that the number of simultaneous users per unit area could increase by two to five times as much as FM. The publication of this result caused a great sensation. In 1978, the CCIR (International Radio Consultative Committee on Radio Consultative) Conference adopted the requirement of promoting spread spectrum research. Henry points out, however, that the average number of channels available per unit area drops to half that of FM. Since then, the research on spread spectrum mobile communication has become increasingly active. Although the research on spread spectrum has only recently attracted people’s attention, its origins are four