Performance analysis of multiple-access multicarrier MFSK systems in Rician fading

We present analysis on the system performance of multiple-access multicarrier M-ary frequency-shift-keying (MC-MFSK) systems over Rician fading channels. A novel approach is used to exploit the fact that in multiple-access MC-MFSK system, the line-of-sight (LOS) carriers of the multiple signals can be combined into a single LOS carrier, and the multiple components of the multiple signals can combined with other Gaussian process. We derive a new probability density function (pdf) for the output of the envelope detector in MC-MFSK systems, which can be applied to compute the system performance and capacity. We also propose a chi-square approximation to the new pf for a large number of signals, which can be efficiently evaluated, and show that this approximation is very close to the exact results. Furthermore, we provide physical explanations on the effect of the number of multiple sub-carriers on the system performance.