Analysis of Per-Channel Equalized Filtered Multitone Modulations Over Time-Varying Fading Channels

We consider the performance of an FMT system with perchannel equalization over frequency-selective time-varying fading channels. Due to the distortion caused by frequency and time selectivity of the fading channel, both ICI and ISI exist in an FMT system and cause performance degradation. By using a per-channel equalizer at the FMT receiver with sufficiently large number of equalizer taps, the ISI can be mitigated significantly, but the ICI still exists. In this paper, the effects of the interference caused by the time-frequency dispersive channel is quantified by analyzing the average system carrier to interference (CIY) ratio of the FMT system under different fading conditions. A closed-form expression for the C/I ratio and its upper bound are provided for the FMT system, which lead to a better understanding of the trade-off between spectral efficiency and system performance degradation. Moreover, comparisons between FMT and OFDM systems under the same channel conditions and spectral efficiency are also provided. Numerical and simulation results of the system C/I ratio further confirm and support the obtained analytical results