Channel coherence in the low SNR regime

Abstract

The effect of channel coherence on the capacity and energy efficiency of noncoherent fading channels at low SNR is studied. A simple characterization is given, and a new approach is developed, which can be used to study a wide variety of problems for communications over a wideband channel. The flat block fading channel is studied, which transmits one scalar symbol per symbol time distorted by a multiplicative fading coefficient and the additive Gaussian noise.