Tracking Angles of Departure and Arrival in a Mobile Millimeter Wave Channel

摘要

Millimeter wave provides a very promising approach for meeting theever-growing traffic demand in next generation wireless networks. To utilizethis band, it is crucial to obtain the channel state information in order toperform beamforming and combining to compensate for severe path loss. Incontrast to lower frequencies, a typical millimeter wave channel consists of afew dominant paths. Thus it is generally sufficient to estimate the path gains,angles of departure (AoDs), and angles of arrival (AoAs) of those paths.Proposed in this paper is a dual timescale model to characterize abrupt channelchanges (e.g., blockage) and slow variations of AoDs and AoAs. This workfocuses on tracking the slow variations and detecting abrupt changes. A Kalmanfilter based tracking algorithm and an abrupt change detection method areproposed. The tracking algorithm is compared with the adaptive algorithm due toAlkhateeb, Ayach, Leus and Heath (2014) in the case with single radio frequencychain. Simulation results show that to achieve the same tracking performance,the proposed algorithm requires much lower signal-to-noise-ratio (SNR) and muchfewer pilots than the other algorithm. Moreover, the change detection methodcan always detect abrupt changes with moderate number of pilots and SNR.