Successive AoA estimation: Revealing the second path for 60 GHz communication system

60 GHz communication system is a viable candidate to support very high data throughput for wireless communication. To compensate for high path loss at 60 GHz frequency, a large number of antenna elements are employed to form highly directional beams for communication range extension. However, communication paths are easily be blocked by human movement. Switching to the second best path when needed is to protect against human blockage. Before switching to the second best path, the device needs to know a list of available alternative paths. Acquiring the list is related to Angle of Arrival (AoA) estimation problem. Though many high resolution AoA estimation algorithms are proposed in the literature, the unique features in the 60 GHz system require special attentions. We propose successive AoA estimation algorithm to utilize the features in the system. The scheme borrows the concept from successive interference cancellation scheme in multiuser detection. It provides compelling performance if there are large signal strength disparities among users, which is also observed in AoA estimation for 60 GHz system. The proposed scheme is very efficient as the AoA estimation step during each iteration is shown to be convex. Numerical results demonstrate that the proposed scheme outperforms other schemes and is shown to be a good candidate to reveal the alternative paths for the 60 GHz system.