卫星通信多址接入方式的比较和分析

Analysis and comparison of TDMA,FDMA and CDMA techniques in satellite communication

在卫星通信中常用的射频多址接入方式,有TDMA、FDMA和CDMA。射频多址接入技术主要解决不同地理位置上的地球站信号如何共用一个卫星转发器问题。文中主要就应用这三种多址技术的卫星通信系统的容量计算和系统利用效率分别进行了详细的讨论和分析,并指出,在占用相同转发器带宽条件下,TDMA系统容量和效率最高。还指出努力提高效率和容量是CDMA系统的关键。

There are three kinds of basic radio multiple access techniques in satellite communication,those are time division multiple access (TDMA),frequency division multiple access (FDMA) and code division multiple access (CDMA). The aim of using radio multiple access technique is to solve the problem of how to share a satellite transponder by the earth stations in different geographical locations. At the condition of occupying the same bandwidth of the satellite transponder by the three kinds of multiple access techniques,the capacities of three satellite systems are calculated and their satellite transponder efficiencies are analyzed in this paper. The result shows that the system capacity of TDMA is the largest and the system efficiency of TDMA is the highest. At the end,the paper points out that the key technique for CDMA system is to improve the system capacity and the efficiency of the satellite transponder.