DGT-based pulse shaping filter for Generalized Frequency Division Multiplexing system

The future wireless communication systems belonging to the next generation will encounter many diverse demands, like the need for data rates that surpass the capabilities of fifth-generation networks, ultra-low power consumption to cater to battery-operated communication sensors, and extremely short response times essential for control applications. A unified physical layer waveform is envisaged to address these flexible requirements, introduced as Generalized Frequency Division Multiplexing (GFDM) for beyond 5G (B5G) communication systems. One of the important features of GFDM is the utilization of flexible pulse shaping filtering in the time domain, resulting in improved performance. In this paper, a pulse-shaping filter is designed for the GFDM system using discrete Gabor representation, discrete biorthogonality condition and Wigner distribution. An analytical expression for the analysis window is derived using the biorthogonality condition. Further, the performance of the GFDM system is analyzed in terms of out-of-band (OOB) radiation and symbol error rate (SER). The results are presented for the Quadrature Amplitude Modulation (QAM) scheme over Additive White Gaussian Noise (AWGN), Rayleigh, Nakagami-m, two wave with diffuse power (TWDP), and Nakagami-q fading channels. The detailed analysis shows that the OOB radiation and SER performance exhibit strong dependence on the choice of the pulse shaping filter.