Low complexity optimization and implementation of pulse shapes for BFDM systems

In this paper, we investigate low complexity numerical optimization, implementation and performance evaluation of biorthogonal pulses for Biorthogonal Frequency Division Multiplexing (BFDM) systems over doubly dispersive channel. In our previous works, we have proposed optimal pulses design based on a numerical maximization of Signal-to-Interference Ratio (SIR) exact expression. In this paper, in order to accelerate the optimization procedure, we undertake the pulse shapes optimization with an approximate expression of the SIR, instead of the exact one. Our approximation of the SIR uses Taylor series of interference and desired signal mean powers. We show through simulations that our new pulses are very close to our previous ones and that they lead to a SIR subtantially equivalent to the exact one. For a performance evaluation of these pulses, we propose to verify if the SIR computed through system level simulation is in conformance with the numerically optimized SIR. More precisely, we simulate a multicarrier transmission system using the optimized pulses. For this aim, we propose an efficient implementation of both the modulator and the demodulator of the system and a simple and efficient method to find out the resulting SIR. Simulations show that the SIR computed through system level simulation matches the maximum achievable SIR obtained through pulses optimization.