Novel satellite digital video TDMA system for business video communications

Abstract

The authors propose an integrated satellite digital video system for business video communications which realizes multipoint to multipoint dynamic channel assignment, simultaneous plural video signal transmission, and efficient use of the transponder transmission power. An offset quadrature phase shift keying (QPSK) modulation scheme with a high-coding-gain high-coding-rate forward error correction scheme obtains compact spectrum characteristics and highly interference-resistant characteristics in nonlinear satellite channels. For backward voice channel transmission from video signal receive-only terminals, a superposed spread spectrum multiple access voice signal transmission scheme over a time division multiple access video signal through one transponder that employs a cochannel interference cancellation technique is proposed.<>