Performance Evaluation of Variable-Rate Polynomial Phase Modulation

A variable rate modulation format is proposed in which polynomial functions of time phase modulate a carrier waveform. The rate of transmission can be varied by changing the coefficient alphabet or by changing the order of the polynomial phase function. The receiver uses a single iterative algorithm to decode the information for all coefficient alphabets and polynomial orders. An increase in spectral efficiency is observed with increase in the order of the polynomial and/or an increase in the size of the coefficient alphabet. Evaluation of the error performance using two proposed decision rules show gains compared to conventional modulation formats over white Gaussian and fading channels. This format is suitable for multimedia communications systems that require variable rate transmission.