A Novel Ramp-based Pulse Shaping Filter for Reducing Out of Band Emission in 5G GFDM System

Due to ever increasing demand of services in the field of mobile communication, the fourth generation based systems has reached a saturation stage. The world today is looking towards fifth generation (5G), which would open doors for a variety of new services. Generalized Frequency Division Multiplexing (GFDM) is a potential candidate for forming the physical layer of the 5G due to its appealing properties such as low out of band (OOB) radiation and optimal use of time-frequency resources. Various filters such as root raised cosine (RRC), Xia pulse, etc. are proposed in the literature for pulse shaping of GFDM waveform. These filters affect the amount of OOB radiations and symbol error rate (SER) performance of the system in different ways. There is always a trade-off between the two performance indices, especially in low latency scenarios. Thus, it is important to design a filter impulse response, which can provide an optimal solution so as to get the best out of the GFDM system. This paper proposes a novel ramp-based finite impulse response filter for pulse shaping the GFDM waveform in the frame structure of tactile internet. The proposed filter makes an effort to address the limitation of the RRC and Xia filters. For the three filters, the power spectral density is calculated with respect to different sub-carriers. The SER v/s signal to noise ratio performance is tested in additive white Gaussian noise (AWGN) channel. Simulation results show that a system with proposed ramp-based filter offers significantly low OOB radiation as compared to RRC filter and Xia pulse. Furthermore, the SER performance of the proposed ramp-based filter is superior to Xia pulse in AWGN channel model.