Nw-Ofdm Using Cyclic Postfix And Windowing For The Embb Waveform Of The 5g/B5g Mobile System

For the eMBB (enhanced mobile broadband) new radio waveform of the 5G and beyond 5G mobile communication system, the spectrum efficiency is the most important figure of merit. Especially, OOB (out-of-band) power spectrum must be reduced to increase the spectrum efficiency and to save the frequency resources. Filtering is the one way to get the sharp OOB spectrum. But, due to the very complicated process and some difficulty to the realization, windowing method has been enlightened than the filtering. WOLA-OFDM (weighted overlap and add - orthogonal frequency division multiplexing) system is the most representative windowing method. However, the WOLA-OFDM system has some serious problem. It has the overlap process in order not to lose the time resource. Due to the overlap of the 2 extensions of copy and addition processes, the left part of the copied and added parts will invade into the right part of the previous OFDM symbol. This is very serious data collision even before the transmission. So, in this paper, to improve the WOLA-OFDM system and to avoid this problem of WOLA-OFDM between the consecutive OFDM symbols, we like to propose an NW-OFDM (new windowing-orthogonal frequency division multiplexing) that uses cyclic postfix and windowing. In this NW-OFDM system there are NW1-OFDM system and NW2-OFDM system, whether the overlapping between the consecutive OFDM symbols is allowed or not. Compared with the conventional WOLA-OFDM system, the proposed NW-OFDM system is simplified and solve the data collision problem, Simulations results show that the proposed NW-OFDM system has comparable OOB spectrum reduction characteristics and can be designed by simple some modification from the conventional OFDM system.