On the bounds of the non-coherent capacity of Gauss-Markov fading channels

In this paper, we discuss the upper and lower bounds of the flat fading Gauss-Markov channel capacity. It is shown that due to phase variations on a correlated channel, the amount of information carried by phase will not grow with SNR asymptotically. As a result, optimal coherent designs or designs based on quasi-static assumptions can not be optimal for correlated fading channels. We also show that channel correlation may provide significant capacity gain over the capacity of independent fading channels. It is also shown that if the input is i.i.d., the asymptotic growth rate of the capacity is the same as that of independent Rayleigh flat fading channels. This indicates that the asymptotic region is very power inefficient.