Analytical results about the robustness of FMT modulation with several prototype pulses in time-frequency selective fading channels

In this paper we study the performance of Filtered Multitone (FMT) modulation systems in time-frequency selective fading channels. FMT generalizes the OFDM scheme through the deployment of a sub-channel shaping pulse. A general analysis framework is reported, and it is specialized to the case of using a sinc pulse, a root-raised cosine pulse, and Gaussian pulse. Quasi-closed form expressions for the signal-to-interference (SIR) power ratio are derived. The results allow to benchmark the multitone system and understand how robust it is to frequency selective time-variant fading. We make a comparison with OFDM both in terms of SIR and bit-error-rate when single-tap subchannel equalization is used. It shows that FMT can have better performance than OFDM due to the better sub-channel spectral containment. We also discuss the usefulness of the SIR results on the design of the prototype pulse in a time-frequency selective fading channel.