Optimal ASK and QAM with non-equal symbol probabilities on Rayleigh fading channels.

Formulas are derived to compute the optimal signal constellation, bit error probabilities, and decision thresholds for M-ASK and QAM with non-equal prior symbol probabilities on Rayleigh fading channels. It is shown that the optimal system can improve average Eb/N0 by 5 dB compared to a conventional system, i.e. a system with source coding, equiprobable symbols, and equal space constellation. [ABSTRACT FROM AUTHOR]