Optimization of OFDM on frequency-selective time-selective fading channels

In mobile radio communication, the fading channels generally exhibit both time-selectivity and frequency-selectivity. Orthogonal frequency division multiplexing (OFDM) has been proposed to combat the frequency-selectivity, but its performance is also affected by the time-selectivity. We investigate how various parameters, such as the number of carriers, the guard time length and the sampling offset between receiver and transmitter, affect the system performance. Further, we determine the optimum values of the above parameters, which minimize the degradation of the signal-to-noise ratio at the input of the decision device.