Research Of Precoding In Millimeter Wave Communication System Under Imperfect Hardware

As spectrum resource becomes more and more scarce,millimeter wave catches more focus.In millimeter wave communication system,researches were focused on precoding which impacts system capacity obviously.However,most researches were involved in ideal channel and ideal hardware,which is not appropriate in practice.Precoding of millimeter wave system under imperfect hardware was researched in this literature:Firstly,the background and significance of this task were introduced,and researches in millimeter wave system and hardware imperfection in millimeter wave communication system was summarized in this part.Then the research direction was point out.In the second part,according to previous researches,a model of receive signal under imperfect hardware was described which was focused on ADC(analog-to-digital)?LNA(low noise amplifier)?and LO(local oscillator).Then,according to the model above,general precoding methods including ZF?BD?PZF?H-BD were simulated under non-ideal hardware,which were based on spectrum efficiency.Observe that under imperfect hardware,general precoding methods above resulted in obviously lower system capacity.Thirdly,for the purpose of improving system capacity,precoding under non-ideal hardware was optimized with the constraint of transmitting power.This optimize problem is not easy to solve,so an easier problem was solved in advance which structured an optimal precoding structure.Then the original problem was solved in detail.The optimal precoding formulate was complex due to its numerous hardware parameters,so BRB search algorithm under ideal hardware was promote to be used in this scenario and the optimal precoding matrix of this problem was searched out.Observe than it got better system capacity than PZF?H-BD precoding under the same scenario.Finally,based on spectrum efficiency performance,how these hardware impact the performance of precoding was analyzed,and some suggestions about how to improve hardware were put forward.