Capacity analysis of multi-beam GEO satellite communication systems with on-board switching

The multiple access method is an important element of satellite communication system, which leads a large extent of the complexity and performance to the systems. The MF-TDMA and MF-CDMA are the two popular multiple access methods of modern satellite communications, with their own advantages and disadvantages, so it is difficult to make a choice in system design. This paper mainly analyses the capacity of the two multiple access methods based on the multi-beam, on-board switching of GEO satellite communication system, also by taking the limits of the satellite power and band width available into the consideration. On the basis of supporting the kind of terminal-to-terminal direct voice communications service for handheld terminals, the joint impacts on the receiving end by the uplink and the downlink have been put into the link calculations. Given the same main parameters of system, the detailed capacity analysis and calculations show that the MF-TDMA scheme is superior to the MF-CDMA in capacity, particularly in the case of power concentrated coverage, and is the best solution of a multi-beam, on-board switching GEO satellite communication system.