  In this paper, the performance of signaling strategies with high
peak-to-average power ratio is analyzed over both coherent and noncoherent
fading channels. Two modulation schemes, namely on-off phase-shift keying
(OOPSK) and on-off frequency-shift keying (OOFSK), are considered. Initially,
uncoded systems are analyzed. For OOPSK and OOFSK, the optimal detector
structures are identified and analytical expressions for the error
probabilities are obtained for arbitrary constellation sizes. Numerical
techniques are employed to compute the error probabilities. It is concluded
that increasing the peakedness of the signals results in reduced error rates
for a given power level and hence equivalently improves the energy efficiency
for fixed error probabilities. The coded performance is also studied by
analyzing the random coding error exponents achieved by OOPSK and OOFSK
signaling.
