Analysis of the Robustness of FMT Modulation in Time-Frequency Selective Fading Channels

In this paper we analyze 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 presented, and it is specialized to the case of using a root-raised cosine pulse (FMT) and a rectangular pulse (OFDM). 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. An analysis both in terms of SIR and bit-error-rate is made. It is shown that the better sub-channel spectral containment of the FMT yields better performance than OFDM.