AVERAGE CHANNEL CAPACITY IN A MOBILE RADIO ENVIRONMENT WITH RICIAN STATISTICS

The Shannon-Hartley theorem for channel capacity presupposes signal tr ansmission over time-invariant Gaussian channels. In a mobile radio en vironment, communications channels have randomly time-variant characte ristics. In this paper, an expression for the average capacity of Rici an fading channels is derived. It is shown that the average capacity o f Rician channels is always lower than that of the Gaussian channel, w hile the Rayleigh channel capacity values represent the worst situatio n. In addition, the Rician channel capacity is examined when reception by a maximal-ratio combining technique with M-branches is employed, i ndicating its positive effect on channel average capacity when weak si gnal power or severe fading conditions are present. Finally, the relat ion between Rician and Rayleigh fading environment with respect to cha nnel average capacity is discussed.