Research On The Algorithm Of Beamforming For Coordinataon Communication

With the development of mobile communication,the mobile data traffic is growing rapidly and the technologes of large-scale antenna and ultra-dense wireless networks have become a hot research area.Due to this,coordination communication has attracted broad attentions.Coordination communication is a technology with the coordination between different nodes to complete the data transmission,which can significantly improve the performance of users and system.In the multi-antenna system beamforming can make better use of channel correlation and spatial resource to alleciate interference and improve the system performance.This thesis considers the beamforming design with different coordination scenarios and the main research work can be divides into two parts as follow:In this thesis,we focus on the beamforming design with the goal of minimizing the backhaul link consumption with imperfect channel condition.First,we use the norm relaxation and semidefinite relaxation to make the problem with the constraints of imperfect channel state information and signal to noise plus interference ratio solvable.Then we propose an iterative link removal strategy based on the relaxed problem to minimize the backhaul consumption.The design is robust due to the consideration of imperfect channel state information and the simulation shows that the proposed algorithm can reduce the backhaul consumption and improve the performance of system remarkably.Beside that,coordination transmission with different networks is studied.And this thesis focuses on the standardization status of Licensed-Assisted Access(LAA).With the introduction of LAA,we propose a cross-carrier beamforming design based on the zero-forcing algorithm with the scenario of LAA coexisting with Wi-Fi.And our goal is to maximize the throughput of LAA system with the strategy of handover to other group and the beamforming design in the period in which the unlicensed frequency resouces are used by the LAA.