Capacity variance of OFDM systems over multipath Ricean fading channels

Capacity variance is an important parameter in the study of system capacity and it can be used to estimate the outage capacity of communication systems. The variance OFDM system capacity over Ricean fading channels is thoroughly investigated. We firstly construct the model of multipath Ricean fading channel and define Ricean factor for multipath fading channel. Based on the channel model, a novel mathematical expression for the capacity variance, as the function of the number of the subcarriers of an OFDM symbol, the signal to noise ratio (SNR) and the power profile of the channel, for Ricean fading channels has been derived. The resultant system capacity variances over Ricean fading channels has also been evaluated by computer simulation and verified by numerical method. Results show that the capacity variance is proportional to SNR and inverse proportional to Ricean factor and the number of paths of the channel. In addition, the joint probability density function (PDF) of two arbitrary correlated Ricean random variables has been provided in an integral form.