Optimal OFDM pulse design, analysis and implementation over doubly dispersive channel

Abstract

This paper considers optimization and implementation of the pulse shape for Orthogonal Frequency Division Multiplexing (OFDM) systems over doubly dispersive channel. The proposed pulse shape is expressed as a linear combination of the most localized Hermite waveforms. In our previous works, we have proposed pulses optimization based on an exact expression of the Signal to Interference Ratio (SIR). In order to accelerate the optimization procedure, we propose an approximate expression of the SIR using Taylor series of interference and desired signal mean powers. For a performance evaluation of the optimized OFDM system, we propose an efficient implementation of both the modulator and the demodulator of the system and an efficient method to find out the resulting simulated SIR. Simulations results, obtained for different values of the dispersion factor, show that the SIR computed through system level simulation matches the maximum achievable SIR obtained through numerical optimization.