Research On Beamforming Algorithm Based On 3D Channel Model

Nowadays,with the rapid development of science and technology,the Internet technology has been applied in many fields and people put forward higher and higher requirements on quality,speed and efficiency of technical service.Similarly,in wireless communications,the demand for network capacity and efficiency is increasing year by year.In order to meet the growing needs,the endless exploration of wireless resources is imperative.Looking back on the history of the development of wireless communication,the discovery of space is a very worthwhile exploration of resources for the future development of wireless communicat io ns to provide unlimited possibilities.As an important part of wireless communication system,Channel model describes the environment in which the signal is located and plays a vital role in evaluating the performance of the algorithm.At present,most of the channel models are based on the 2D,without elevation angle,so it cannot be applied in the real scenario.In this thesis,the development status of 3D channel model and the process of 3D channel modeling are introduced.Based on the WINNER II channel model,the spatial pitch angle information is added and the channel is 3D modeled.This channel takes into account the three-dimensio na l nature of the mobile terminal and the base station,and more realistically describes the propagation environment experienced by the signal from the transmitter to the receiver.There are many kinds of traditional beamforming algorithms.However,most of them are two-dimensional,only include horizontal azimuth information,and does not meet the actual situation.In this paper,the traditional algorithm is improved,and the vertical beamforming algorithm is obtained by considering the vertical pitch angle informat ion in the case of single user and multiuser.In the algorithm,two kinds of optimization about BS tilting angle are included: dynamic optimization and static optimization where the former obtains the BS tilt angle dynamically according to the channel,and the latter obtains the best dip angle according to the statistical information and remains the same.By optimizing the BS tilt angle,so that the beam in the vertical domain at the user,you can reduce the interference and improve average rate.At the same time,considering the gain of antenna in horizontal and vertical fields,a beamforming algorithm is proposed to optimize the BS tilt angle and BS azimuth angle so that the beam is aligned with the user in two dimensions at the same time,avoiding the interference from users with different heights or different horizontal azimut hs.Furthermore,the two algorithms based on 3D channel model are simulated.The results show that the dynamic optimization of the down-dip method can achieve an average rate gain of about 2 compared with the static-optimized dip angle method.The dynamic optimiza t io n about two dimensions is better than the static optimization of two dimensions,which can yield a rate gain of about 2.8,and beamforming algorithm that optimized two dimens io ns can achieve a higher average rate than an algorithm that only optimized one dimension.In the multi-user,the dynamic optimization of the down-dip method can achieve a weighted sum rate gain of about 1d B compared to the traditional down-slope method in the conventional SBT scheme,and compared with the beamforming algorithm with only one dimension optimized,beamforming algorithm with two dimensions optimized can achieve higher weighted sum rate.Finally,this thesis summarizes the work and combines with the development trend of wireless communication,research work about beamforming in the future is prospected.