TABLE OF CONTENTS Time-division multiple-access (TDMA) systems, described in Chapter 8, have been utilized for providing high-capacity flexible digital satellite communication services. For example, the INTELSAT-V satellites, in an all-digital TDMA mode, could transmit over 1 billion bits of information a second (1 Gb/s) enough capacity to allow the Encyclopedia Britannica to be sent from, say, the United States to Italy six times a minute. The INTELSAT-VI satellite is planned to attain its highest capacity in the satellite-switched (SS-TDMA) mode. In this mode it uses a pair of 6 6 dynamic RF switches and is expected to have an operational capacity of 35,000 digitized voice circuits or the equivalent of 2.5 to 3.0 Gb/s (10 9 bits/s) [Astrain, 1981].
The phenomenal growth rate in the demand of satellite circuits and services, as described in Chapter 1, together with the increase in the number of digital communication satellites and their increased capacity, necessitates a detailed review of transmission and modulation procedures. One of the major factors contributing to the cost of TDMA and of related satellite systems is the generation of high transmitted power at both the earth station and the satellite. To achieve this high output power, which offsets the large propagation losses, large transmit and receive antennas are also required for economic reasons. For a cost-effective system, the radio-frequency (RF) amplifying devices must be operated in a nonlinear mode (i.e., close to saturation). These nonlinearities degrade the performance of digitally...
