Methods of multiple access for terrestrial radio networks

Abstract

The content of this work is focused on the methods of multiple access for terrestrial radio network. These methods are exploited by the systems second and third generation of mobile networks. Specification the basic characteristics these methods is responsible part for inquest the correspondent specificities. Reason is that, that the wireless mobile communication it is possible split by three generation. First is NMT, with analog frequency modulation, which dont make use already, because has considerable disavantages . Analysis second generation mobile systems GSM leads to determination to many advanta- ges hereof system, who be based on methods FDMA, TDMA, CDMA. Description these methods is specialized on their spreading properties. Third generation of mobile systems UMTS is characterized wideband technology WCDMA, making use two duplex methods (FDD, TDD). Both methods provide higher efficiency of recovery frequency spectrum . All the theoretical approaches are examined in the last part of this work.it´s then possible after complete analysis these methods, make a design and a realization. In this event was used the computer programme Matlab–Simulink for simula- tion of duplex method WCDMA-FDD. Evaluation of this technology provides confrontation with second generation GSM