Low PAPR DM-RS Design for 5G Systems Operating in High Frequency Bands

3GPP 5G New Radio (NR) wireless access technology will support communication at bands ranging from sub GHz to millimeter wave. For communication at millimeter wave, e.g., at 60 GHz, the transmitted signal experiences severe attenuation, due to outdoor-to-indoor penetration, oxygen absorption, etc., significantly degrading the link budget performance of the NR system. In order to achieve good coverage for NR systems, operating at all bands, it is important to ensure the support of power efficient waveforms for physical channels carrying data and reference signals. Demodulation reference signals (DM-RS) are used in 5G NR systems to assist receivers in estimation of the wireless channel for subsequent coherent processing of the corresponding received data on the physical channel. In this paper, we propose a novel design of DM-RS that achieves channel estimation performance similar to NR Release 15 DM-RS, while providing higher power efficiency. The proposed DM-RS design in conjunction with power efficient waveforms for physical channel can thus be used to enhance coverage of NR systems operating at higher carrier frequency ranges of millimeter wave bands, e.g. 60 GHz. We corroborate our claims via computer simulations.