Title :
Doubling the capacity of a communications satellite system
Author :
Bradley, James F. ; Cooper, Paul W.
Author_Institution :
AT&T Bell Labs., Holmdel, NJ, USA
fDate :
10/1/1997 12:00:00 AM
Abstract :
Two one-way channels are normally used in digital two-way voice communication. Each channel is in effect-used only one half the time. A recent discovery of ours recognized that any one-way channel within a satellite spot-beam can be accessed by anyone in the footprint of the beam. In a two-way voice call, the two parties alternate (in principle) in their transmissions-when one speaks the other is silent. Therefore, the two can share a single one-way channel and provide continuous use of the channel, their respective transmissions interleaved with one another. This condition is unique to intrabeam communication via satellite (or balloon). In a satellite system, capacity is a valued commodity, where capacity is limited by allocated bandwidth and power available. Under those two constraints of bandwidth and power limitation, the discovery described generates a doubling of capacity. This article addresses this concept and some of the engineering challenges and opportunities arising therefrom
Keywords :
access protocols; channel capacity; code division multiple access; codes; frequency division multiple access; satellite communication; voice communication; CDMA codes; FDMA; bandwidth limitation; beam footprint; capacity doubling; channel capacity; communications satellite system capacity; digital two-way voice communication; engineering challenges; engineering opportunities; intrabeam communication; one-way channels; power limitation; satellite spot-beam; two-way voice call; Artificial satellites; Constraint optimization; Downlink; Filling; Frequency division multiaccess; Optical fiber cables; Power system modeling; Resource management; Satellite communication; Tail;
Journal_Title :
Communications Magazine, IEEE