A (4,12) circular signal set for satellite transmission

Presents the results of a computer simulation study of a spectrally efficient modem for digital satellite transmission. The modem transmits a (4,12) circular set signal (i.e. with a 16-ary symbol alphabets) over a satellite link, where the high-power amplifier (HPA) at the earth station transmitter introduces nonlinear signal distortion into the signal. A comparison on performances is made between the signal and a 16-ary quadrature-amplitude-modulated (16-ary QAM) signal with a rectangular signal set. The results are used to select the preferred signal set for spectrally efficient transmission over satellite links. >