POPS-OFDM: Ping-pong Optimized Pulse Shaping-OFDM for 5G systems

Recently, Orthogonal Frequency Division Multiplexing (OFDM) has gained more attention as an effective technique for high data rate future wireless communication systems. In order to provide maximal spectral efficiency, the prototype waveform, used in these systems, must guarantee orthogonality even the rapidly time-varying and strongly delay-spread characteristics of the channel propagation. However, its performance gain degrades in the presence of the system Inter-Carrier Interference (ICI) and Inter-Symbol Interference (ISI) which make it essential to develop an efficient technique to overcome these interference over the time-frequency dispersion of the radio mobile channel. In this paper, we propose a Pingpong Optimized Pulse Shaping-OFDM (POPS-OFDM) algorithm that maximizes the received Signal to Interference plus Noise Ratio (SINR) by systematically optimizing the OFDM waveforms at the Transmitter (TX) and Receiver (RX) sides. We derived the exact closed-form expression of the SINR of the considered multicarrier system and the optimized waveform is searched as a linear combination of several of the most localized Hermite functions. The results confirm the advantage behind the POPS-OFDM algorithm in enhancing the performance compared to multicarrier systems using conventional waveforms. Simulations are given to support our claims.