Diversity Cutoff Rate Evaluation of the Rayleigh and Rician Fading Channels

This paper presents expressions for the cutoff rate R0diversity transmission over the Rayleigh and Rician fading channels withM-ary orthogonal signaling. These expressions include the unquantized R0forD-fold diversity, which upper bounds the channel performance, and hard decision and four- and eight-level soft decision quantized R0expressions. Tradeoffs betweenDand the number of quantization levels for equivalent performance are presented for the unquantized and quantized channels. These tradeoffs illustrate the reduction in signal energy, system bandwidth, and system complexity by increasing the number of quantization levels, thereby allowing a reduction inD.