Performance analysis of MIMO MRC systems over Rician fading channels

Abstract

This paper extends the Khatri distribution (see Khatri, C.G., Ann. Math. Stat., vol.35, p.1807-10, 1964) of the largest eigenvalue of central complex Wishart matrices to the non-central case. It then applies the resulting new statistical results to obtain closed-form expressions for the outage probability and the channel capacity complementary cumulative distribution function (CCDF) of multiple-input-multiple-output (MIMO) systems employing maximal ratio combining (MRC) and operating over Rician fading channels. When applicable, these expressions are compared to special cases previously reported in the literature dealing with the outage probability of (i) MIMO systems over Rayleigh fading channels and (ii) single-input-multiple-output (SIMO) systems over Rician fading channels. As a double check these analytical results are validated by Monte-Carlo simulations and, as an illustration of the mathematical formalism, some numerical examples for particular cases of interests are plotted and discussed. These results show that, given a fixed number of total antenna elements, (i) SIMO systems are equivalent to multiple-input-single-output (MISO) systems and (ii) it is preferable to distribute the number of antenna elements evenly between the transmitter and the receiver for a minimum outage probability performance.