数字蜂窝式移动电话系统现状与发展

目前在世界上许多国家运营的蜂窝式移动电话系统如北欧四国的 NMT、美国的AMPS、联邦德图的 C 网、英国的 TACS、日本的 NAMTS,我国在北京、上海和广州运营的 TACS 和爱立克森系统都属第一代模拟式移动电话系统。为了满足更多用户的要求,建立符合统一技术标准的系统,欧州许多国家在移动通信专业组(GSM)组织协调下,提出了多种系统方案,即第二代数字蜂窝式移动电话系统试验系统方案。本文对这几种系统,重点对 CD900、S900D,作了全面介绍。并从多址技术、信道编码、语音编码、调制技术以及经济性等方面进行了分析和评估。

Digital honeycomb mobile telephone systems:Now and Future

Now the service honeycomb mobile telephone systems of many countries in the world are analog mobile telephone systems of the first generation,such as NMT of four countries in North Europe,AMPS of America,C network of F.R.G, TACS of England,NAMTS of Japan.TACS and Annekson system of Beijing, Shanghai and Guangzhou in our country are also analog mobile telephonc systems of the first generation.In order to meet major user and set united technical standard system, many countries in Europe has proposed a number of system versions with the corperation of GSM,That is experimental system versions of the secondary generation digital honeycomb mobile telephone systems.In the paper several systems,which emphasise upon CD900 and S900D,are described comprehensively.Analysis and valuation are made from the view of multipe address technigue,channel coding, speech coding,modulation technique as well as economy.