Experimental Demonstration of Wave Source Location Estimation Method for Spectrum Sharing in 28-GHz-Band 5G System

This paper experimentally investigates a direction of arrival (DOA)-based wave source location estimation method for spectrum sharing in millimeter-wave band local and private fifth-generation (5G) mobile communication systems. In the DOA-based wave source location estimation, it is important to extract a line-of-sight (LOS) component from the received signals. Considering that in 5G systems, synchronization signal / physical broadcast channel (SS/PBCH) blocks are transmitted with beam-sweeping for initial access, our measurement system performs the DOA estimation based on the maximum-power block where the LOS component seems to be dominant. In the DOA estimation, taking advantage of the sparsity of the propagation channels in both angular space and delay time domains, our measurement system adopts the compressed sensing (CS)-based approach. As for the measurement antenna, a directional pattern is employed, which enables the estimation with only four antenna elements. We experimentally demonstrate the performance of the wave source location estimation in an outdoor environment using a commercial 28 GHz-band 5G base station (BS). Experimental results show that our measurement system achieves a location estimation error of 5.8 m based on 20 measurements.