Impact of Pulse Shaping Design on OOB Emission and Error Probability of GFDM

Generalized frequency-division multiplexing is one of the multi-carrier modulation schemes currently under study for beyond fifth generation (B5G) cellular systems. The main characteristics of generalized frequency-division multiplexing (GFDM) are the flexible time-frequency structure of data blocks, making it customizable according to various service requirements in B5G scenarios, and the low out of band (OOB) emission, which can be achieved by means of a flexible time-domain pulse shaping of individual sub-carriers. With this motivation, a new pulse shaping filter is proposed and its benefits on the OOB emission and on the symbol error probability (SEP) are demonstrated. The eye diagram, used as a performance evaluation parameter at the transmitter, shows that the proposed pulse has better vertical sharpness than root-raised cosine (RRC) filter and, therefore, it gives better OOB emission. Along with vertical sharpness, it has better horizontal sharpness, which means that the proposed pulse has better tolerance to inter-symbol interference (ISI). The SEP performance is evaluated by means of Monta Carlo simulations in case of 16-QAM transmission over an AWGN channel. Analytical expressions of SEP are also presented.