Fundamental limits on symbol rate in frequency selective continuous fading channels

We consider fundamental limits on the symbol rate in frequency selective continuous fading channels. We show the relationship between the upper and lower bounds on the symbol rate set by the delay spread and the Doppler frequency of the channel respectively. We assume training-based channel estimation without tracking, and coherent detection without equalization. An approximation is derived for simulating channels with small delay spread using symbol period spaced samples. Simulation results with a two-path channel model are presented, including bit error rate (BER) and maximum throughput as functions of normalized delay spread for fixed products of delay spread and Doppler frequency. We also discuss the general implications of these results