WF-OFDM (windowing and filtering OFDM) system for the 5G new radio waveform

Abstract

The 2 approaches for the 5G new radio waveform design are the filtering and windowing for the spectrum efficiency improvement by reducing the OOB(out-of-band) power spectrum. As filtering method, UFMC (universal filtered multicarrier), FBMC (filter bank multicarrier) and f-OFDM (filtered orthogonal frequency division multiplexing) waveforms are the potential candidates for a new waveform for 5G system. Another possible approach is to use the windowing in the conventional CP-OFDM system in order to reduce the OOB power spectrum. W-OFDM (window orthogonal frequency division multiplexing) is typical and show comparable performance. Each approach has some advantages and disadvantages together. The best OOB reduction performance can be shown in FBMC system. However, FBMC system is the most complicated and cannot support the general M-QAM (M-ary quadrature amplitude modulation) format. So, it is very important to design a novel OFDM-based waveform that has the similar OOB power spectrum to the FBMC and support the general M-QAM modulation as well. In this paper, we like to propose a WF-OFDM System for the 5G and 5G beyond mobile system waveform design. This WF-OFDM system uses a combination method of the filtering and windowing to get the synergy effect, so that the spectrum efficiency may be increased by reducing the OOB (out-of-band) power spectrum. 4 kinds of WF-OFDM systems are devised depending on the filtering and windowing positions for the OOB performance improvement. Simulations results show that the proposed WF-OFDM system has comparable or better OOB spectrum reduction characteristics to FBMC system. Especially, the proposed system WF-OFDM # 3 and #4 show the remarkable OOB reduction performance even in the short window length of 6 or 8.