cdma技术（cdma技术）.docVIP

cdma技术（cdma技术） 1.1.CDMA development background Release time: 2005-10-25 source: Blog [font: normal large] closes this page for comment CDMA technology has been widely applied in the research of military anti-jamming communication in 1989,.11 months, Qualcomm field tests showed that the CDMA in the United States for cellular mobile communication capacity, and through theoretical derivation of the 20 times the capacity of AMPS. This exciting result quickly made CDMA a global hot topic. 95 years, the CDMA public network in Hongkong and the United States began to be put into commercial use. 96 years, Korea carried out large-scale commercial with its own CDMA system, developed 1 million 500 thousand users in the first 12 months. In 1998, the number of CDMA users worldwide reached about 5000000, and CDMA research and business reached a climax. Some people said that 1997 was CDMA years. Of the 2958 PCS operating licences sold in the United States, CDMA accounted for 51%, D-AMPS accounted for 20%, and GSM accounted for 28%. In 1999, CDMA grew up in Japan and the United States, with the global growth rate as high as 250%, and the number of users reached 20 million. Chinas CDMA development is not too late, there are long-term military research technology accumulation, 93 National 863 program has carried out CDMA cellular technology research. 94 years, Qualcomm first built a technical test network in Tianjin. In 1998, the the Great Wall CDMA commercial test network with 140 thousand capacity was built in Beijing, Guangzhou, Shanghai and Xian, and a small number of commercial enterprises started. China Unicom also plans to build CDMA commercial test networks in Guangdong, Beijing, Tianjin and Shanghai. South Koreas CDMA digital cellular mobile communications has developed rapidly under the powerful organization of the government. The CDMA network has developed to 4 million users in just over a year, and its user density is far higher than that of the Pearl River Delta region wh