Analysis and optimization of the performance of OFDM on frequency-selective time-selective fading channels

In mobile radio communication, the fading channels generally exhibit both t ime-selectivity and frequency-selectivity. Orthogonal frequency-division mu ltiplexing has been proposed to combat the frequency-selectivity, but its p erformance is also affected by the time-selectivity. In this paper, we inve stigate how various parameters, such as the number of carriers, the guard t ime length, and the sampling offset between receiver and transmitter, affec t the system performance. Further, we determine the optimum values of the a bove parameters, which minimize the degradation of the signal-to-noise rati o at the input of the decision device.