Terminal transmit adaptation for optimal link availability

Abstract

The techniques of Terminal transmit adaptation are critical for achieving maximal channel throughput when the link loss exhibits large variation. In this paper, some technical issues regarding transmit power control and mode adaptation in satellite communication (SATCOM) systems are addressed. The transmit adaptation is explored in terms of optimizing the link availability. The analysis extends the common assumption of white Gaussian noise channel to include the case of color noise interference, which is practical in applications as bandwidth resource becomes less sufficient to the demands. Based on this extended assumption, the need of differentiated power adaptation criteria is demonstrated. A closed-loop power control and mode adaptation scheme is subsequently derived to meet that operational need. In addition, a generic case of power-controlled carriers operating among non-power-controlled carriers is analyzed and an approach for mitigating the interference impact is given. The presented analysis and designs are intended for user terminals to accommodate potentially large link variation that exists in both commercial and military Ka-band. They are even more critical for military EHF satellite SATCOM systems.