Abstract:

In this paper, we develop a general reduced-rate orthogonal frequency division multiplexing (OFDM) transmission scheme for inter-sub-channel interference (ICI) mitigation in a high-mobility environment. By transmit and receive preprocessing, we transform the original OFDM system into an equivalent one with fewer sub-carriers and significantly reduced ICI. A general structure of transmit and receive preprocessing matrices is developed so that all sub-channels in the transformed OFDM system have a common average signal-to-interference ratio (SIR). By utilizing channel statistics, we further optimize the preprocessing coefficients to maximize the SIR. Numerical and simulation results demonstrate that the proposed reduced-rate OFDM transmission achieves significant performance improvement over the existing ICI self-cancellation schemes.