Research On The Hybrid Beamforming For Uplink Transmissions Of60Ghz Millimeter-wave Communications

60GHz Millimeter-wave communications system is attracting great attentions by the industry and academia in the short-range wireless communications research areas, because of the advantages of unlicensed spectrum resources, international versatility, high-speed, wide-bandwidth and so on. In addition,60GHz millimeter wave loss seriously in free space communication path, thus, it is a unique advantage for short-range wireless communication transmission security, which is suitable for short-range high-speed wireless personal area network. Meanwhile, since the feature of integrated simply in millimeter wave system, beamforming technology is widely applied to improve the quality of transmission and enhance the capacity of system. The topic of this article comes from the project of National Natural Science Foundation of China (No.6127118).This article will focus on uplink hybrid beamforming technology research for60GHz communications system, based on analysis of the60GHz millimeter wave communication principle and the relevant international standards. There are two categories in smart antenna beamforming, one is the fixed codebook beam switching, the other is adaptive beamforming. Considering on the complexity,60GHz millimeter wave communication system always choose the former. But it is difficult to maximize transmission performance due to its restricted precision; and it can’t effectively suppress interference between multi-link, the program because of sidelobe gain. In this paper the hybrid beamforming technology based on codebook for60GHz uplink communication system is proposed to compromise between performance and complexity. The beam switching based on predefined beam codebook is applied at the transmitter; while adaptive beamforming are applied at the receiver. We has proposed beamforming algorithm applies to a different scene. Matlab simulation platform will simulate the performance of two schemes, scientific analysis of simulation results further verify the validity of the the hybrid beamforming algorithm to enhance transmission performance.The following are the innovative in this paper:(1)Hybrid beamforming based on DOA estimation:Firstly use two-level training mechanisms to search for optimal beam based on IEEE802.15.3c standard codebook, secondly estimate direction of arrival (DOA) of the desired and the interference signal, and then calculate initial value of weight vector by nulling beamforming algorithm, in the end, use the further adaptive LMS iterative algorithm to get optimal beam.(2)Efficient Hybrid beamforming based on SWR beamswitching:firstly, stepwise refinement beam search (SWR) is modeled as a two-dimensional plane of the beam number numerical optimization problems. On this basis, and further the RLS adaptive algorithm can quickly obtain the optimum beam.