OVERVIEW

In the digital satellite communications community Dr. S.J.Campanella is known as a principal architect of TDMA/DSI technology. He wrote numerous benchmark papers and has made lasting contributions in the areas of signal processing, SCPC, FDMA, and TDMA systems. Dr. D.Schaefer is a well-known digital signal processing and satellite communications research engineer and manager. I wish to thank both of them for this comprehensive chapter on the principles and applications of domestic and international TDMA systems.

Dr. K.Feher

8.1 INTRODUCTION

Time-division multiple-access (TDMA) is a method of time-division-multiplex transmission of digitally modulated carriers used for establishing communications links among the earth stations of a satellite network. In a TDMA system, each participating station transmits one or more traffic bursts, synchronized so that they occupy assigned nonoverlapping epochs in a TDMA frame. This is illustrated in Fig. 8.1. Each station s burst is synchronized so that at the time of arrival at the satellite it is the only signal present and no collision occurs with the traffic burst of any other station. The traffic bursts are amplified by the satellite transponder and retransmitted in a downlink beam which is received by all of the participating stations. Thus all stations in the network can receive the traffic bursts and select from them the traffic destined for...