Outage Capacity Analysis for OFDM Decode-and-Forward Systems in Frequency Selective Rayleigh Fading Channels

This letter investigates a decode-and-forward two-hop relaying system consisting of one source, one relay and one destination, in which orthogonal frequency division multiplexing (OFDM) is used. We present an outage probability analysis based on approximating the probability distribution function of the total capacity by a Gaussian distribution. Tight approximations on the outage probability assuming correlated OFDM subchannels are found. As a special case, independent and identically distributed (i.i.d.) OFDM subchannels are also addressed, where a closed form solution to the variance of the total capacity is obtained, leading us to even tighter approximations on the outage probability.