A Reliable Detection Scheme under Non-cooperative Reception for BS Discovery in Millimeter Wave Systems

Due to severe isotropic path loss at millimeter wave (mmWave) frequencies, highly directional transmission is required to achieve high beamforming gain. However, this directional transmission complicates initial access (IA) for mmWave communications. In this paper, we formulate the blind base station (BS) discovery and synchronization in IA process as a bivariate hypothesis detection test, and then propose a reliable and effective detection scheme under non-cooperative reception for mmWave cellular networks. In the scheme, three scanning modes are introduced to intercept signal, namely single-fixed direction scan, polling direction scan, half-direction scan. We derive two different detectors based on energy and correlation, respectively. Through analyzing the test statistics at different delays, the BS time offset is estimated coarsely at UE receiver. Simulation results show that the detection performance of our proposed detectors for mmWave BS discovery is close to the theoretical analysis, and the polling direction scan is more accurate and reliable for mmWave system with narrow beams at low signal-to-noise ratio (SNR).