Research On Suppression Of Pilot Contamination In Massive MIMO System

Massive MIMO system has the enormous throughput of system and high anti-interference ability,and has become the key technology in 5G time.But it is pity that the pilot contamination is the condition of the Massive MIMO system based on TDD.When the cell in the system recieves the non-orthogonal pilot transmitted by adjacent cell,it will result in errors in the channel estimation and affect the system performance.So,if we can eliminate the pilot contamination in the Massive MIMO system,there will be a great development in the mobile comunication field.This work concerns on three aspects.Firstly,we work on the channel estimation,a more accurate channel estimation technology can adjust the errors resulted from pilot contamination and we mainly research the EVD-ILSP jointed channel estimation Secondly,we work on the precoding technology,which can make up the shortfall of the signal detection technology,in this chapter,we give the detailed derivation of the pilot contamination precoding,and finally,we research the pilot assigning on the pilot conatmination.The point in this thesis is the pilot contamination remission plan based on frequency division.The plan learn from the frequency reuse technology in LTE system.It devides the system bandwidth into serval parts so the pilot contamination can be reduced.The Matlab simulation results comfirmes the plan can improve the system performance.