Abstract

A discrete-time single-user channel with correlated Rayleigh fading is analyzed. At low SNR, the capacity of such a channel is known to be achieved by input signals with large peak powers. Since such burstiness in the input signal may not be practically feasible, the possibility of such signals is eliminated in the model by imposing a peak power constraint on every input symbol. A simple expression is given for the capacity per unit energy, in the presence of a peak constraint. The proof uses an adaptation of the simple formula of Verdu to a channel with memory. In addition to bounding the capacity of a channel with correlated fading, the result gives some insight into the relationship between the correlation in the fading process and the channel capacity.

Citations