A general framework for the calculation of the average outage duration of diversity systems over generalized fading channels

This paper presents two approaches for the calculation of the average outage duration (AOD) of diversity systems over generalized fading channels. First, a "classical" probability density function (pdf)-based approach is used to obtain exact closed-form expressions for the AOD of maximal-ratio combiner (MRC) over independent and identically distributed (i.i.d.) Rayleigh and Rice fading channels. On the other hand, relying upon a numerical technique for inverting Laplace transforms of cumulative distribution functions, and in conjunction with the calculation of the joint characteristic function (CF) of the combined output signal-to-noise ratio process and its time derivative, a CF-based approach is adopted to compute the AOD of MRC over non-i.i.d. Rayleigh and Rician diversity paths. The mathematical expressions are illustrated by presenting and interpreting numerical results/plots, showing the impact of the power delay profile, the angles of arrival, and the angle spreads on the AOD of diversity systems operating over typical fading channels of practical interest.