A Hierarchical Beam Search Algorithm with BetterPerformance for Millimeter-Wave Communication

Due to the severe signal attenuation of millimetre-wave communication systems, the large antenna arrays are required to achieve high power gain via utilizing beamforming technique at both transmitter and receiver. To settle the problem that the exhaustive search algorithm is computationally prohibitive to obtain the narrow beams accurately, hierarchical search whose performance is strongly correlated with the codebook design has been widely used to reduce the search complexity. In this paper, we rotate hierarchical codebook with half beam width and enlarge the search range properly in hierarchical search process to mitigate the effects that lower power gain at the edge of beams makes performance degradation in beam training. Simulation results show superiority of the improved hierarchical search over traditional one with acceptable complexity.