UTW-OFDM-based 5G New Radio with Low Out-of-band Emission

Abstract

For the 5G and beyond, the UTW-OFDM has been proposed as one of the new-waveforms which can strongly suppress out-of-band emission (OOBE) and has high compatibility with the CP-OFDM-based system currently used for the LTE. In the UTW-OFDM system, interference generated by windowing is suppressed by using channel coding, and the practicality of UTW-OFDM has been shown for the IEEE 802.11af system using the convolutional coding and the LTE system using the turbo coding Meanwhile, to our best knowledge, the UTW-OFDM-based 5G system using low-density paritycheck (LDPC) coding has not been presented. In this paper, the authors describe how the UTW-OFDM can be applied to 5G new radio (NR). Firstly, the authors point out that common calculation methods of the log-likelihood ratio (LLR) in the decoding process of the LDPC coding degrade the communication quality, especially in a high SNR environment. Then, an adjustment method of the LLR is proposed to mitigate the degradation of the communication quality and demonstrate that the proposed method strongly suppresses OOBE with maintaining the communication quality when applying the UTW-OFDM to the 5G NR.