Optimized waveform for energy efficient ranging

Mobile communication terminals exploit existing reference signal structures for propagation delay based positioning. However, the used waveforms are not optimized for energy efficiency and improved ranging performance for positioning. Recently, a parametric waveform with adaptable power spectral density has been proposed in the context of 5G, and has shown an improved ranging performance. In this paper, we investigate the energy reduction of a ranging signal for a targeted ranging performance by adjusting the parametric waveform. We focus on the newly opened 28 GHz frequency band offering 850 MHz of contiguous bandwidth in the United States. Based on derived Ziv-Zakai lower bounds and a mmWave path loss model with shadow fading we determine the optimal waveform parameter. Our results show a transmit power reduction of 4.77 dB compared to existing reference signal structures. Furthermore, we show a link budget example in the context of ITS positioning.