We examine four-dimensional modulation schemes in view of their application to digital satellite communications systems. Equal-energy signal sets, signals carved from lattices, convolutionally-encoded, and trellis-encoded schemes are compared by evaluating their performance over a channel that includes linear filters, nonlinear amplifiers, and carrier and timing recovery circuits. Among the schemes considered here, trellis-coded modulation seems to offer the best tradeoff between performance and complexity
Date of Conference: 29 Nov-2 Dec 1993