Design and Performance Comparison of W-OFDM Under the Nonlinear HPA Environment

Recently, the spectral efficiency improvement of wireless and cellular communications is very important. Several waveforms have been proposed in order to satisfy key performance indicators of the 5th generation (5G) cellular communication. Universal filtered multi-carrier (UFMC) and filter bank multi-carrier (FBMC) and the filtered orthogonal frequency division multiplexing are typical candidate for 5G waveform, but they have some advantages and problems as well. In this paper, a weighted orthogonal frequency division multiplexing (W-OFDM) is considered since W-OFDM has pretty low complexity and comparable merits. In this paper, at first, we describe the system model and operation principle about UFMC, FBMC, and W-OFDM system. Next, we evaluate the out-of-band (OOB) power spectrum and bit error rate (BER) performance of these systems in the linear or nonlinear HPA. Simulation results show that OOB power spectrum and BER performance of UFMC, FBMC, and W-OFDM are similar in the linear operation. From the implementation point of view, if these performance and characteristics are similar, low-complexity is very decisive for the communication processing speed that is very important to the low latency and ultra-fast processing in the receiver. Additionally, under the nonlinear HPA environment, W-OFDM system is more advantageous because W-OFDM system uses a simple time-domain windowing technique in order to reduce OOB power.