A comprehensive study of universal time-domain windowed OFDM-based LTE downlink system

For the 5G system and beyond, several new-waveforms with low out-of-band emission (OOBE) have been proposed to improve spectral efficiency. The universal timedomain windowed OFDM (UTW-OFDM) have been proposed as a waveform that has the low OOBE characteristics and high compatibility with the conventional cyclic prefix OFDM (CP-OFDM)-based systems. To indicate the feasibility of the UTW-OFDM-based system in the 5G and beyond, the comprehensive evaluation of the UTW-OFDM-based LTE system is important, however, the evaluation of the UTW-OFDM-based LTE system complexity has been not reported. Furthermore, the communication quality of the UTW-OFDM-based LTE system was evaluated by using BER characteristics on the short delay multipath propagation channel in the previous studies. In this paper, to show the feasibility of the UTW-OFDM for the 5G and beyond, the complexity of the UTW-OFDM-based LTE downlink (DL) system is evaluated and compared with one of the LTE-DL system with the conventional CP-OFDM and the filtering-based waveform (UF-OFDM). The complexity of the conventional CP-OFDM-based system and the UTW-OFDM-based system is about 0.45 % of the complexity of the UF-OFDM-based system. Furthermore, the communication quality of the UTW-OFDM-based LTE-DL system is evaluated by using BLER on the 3GPP Extended Typical Urban (ETU) channel model with the 70 Hz Doppler shift. The UTW-OFDM-based LTE-DL system can improve the OOBE of the conventional CP-OFDM-based LTE-DL system by 45 dB with only 2.0 dB deterioration of EN0 to achieve BLER = 10−1 even if the 64QAM is applied with a half coding rate.