Generalized Pattern Search for Beam Discovery in Millimeter Wave Systems

The use of beamforming techniques in millimeter wave systems is crucial for overcoming poor scattering channel impairments. This directional transmission and reception method compels the base station and mobile station to conduct exhaustive spatial beam search, i.e., to determine directions with optimum gains. Consequently, this technique results in high computational complexity, prolonged discovery times and energy inefficiency. Hence this paper proposes a novel initial beam discovery algorithm for sparse millimeter wave channels in non-line of sight outdoor environments. The discovery problem is formulated as an optimization problem, and a modified form of coordinated generalized pattern search is presented to mitigate the aforementioned limitations. Results show that the proposed algorithm delivers significant performance enhancement compared to existing solutions.