Effective Beam Alignment Algorithm for Low Cost Millimeter Wave Communication

The large unlicensed bandwidths in mmW bands promise to satisfy the need for higher throughput in cellular systems. At these frequency bands, the free space path loss have to be mitigated by utilizing directional antennas. However, RF hardware face more difficulties compared to lower frequency bands due to implementation impairments and costs. Thus antenna arrays with one RF chain and limited beam-steering capabilities are commonly used in reality, limiting the degree of freedom for beam-alignment algorithms.Scalable beamwidth in order to use IEEE 802.11ad algorithms is not realizable in some hardware setups. Therefore, a beam searching algorithm with non-scalable beamwidth is presented. To the best of the author's knowledge, existing algorithm rarely consider these restrictions except the well-known exhaustive beam searching. This paper proposes a novel approach, which can reduce the amount of required iterations for the beam searching procedure significantly compared to exhaustive search.