Pilot Contamination Alleviation In TDD Based Massive MIMO System

The uncontrollable and rapid accretion of mobile phone data traffic making big challenge for the future of the 5G cellular network.According to several studies,the demand for data traffic will likely to increase 10,000 fold by 2025.To avail high spectral efficiency(SE)and data rate,the current cellular network will however,be unable to handle this situation.For improving capacity or spectral performance and efficiency,Time Division Duplex(TDD)massive Multiple-Input Multiple-Output(massive-MIMO)is considered as the key technology in the future wireless cellular networks(5G)which would require installing of hundreds or even thousands of cellular antennas and user terminals connected to the Base Stations(BS).However,Pilot Contamination(PC)-a well-known challenge in massive MIMO caused by channel estimation error-disrupts and demarcates these required objectives.This thesis,put forward an innovative pilot allocation strategy i.e.Cell Splitting and Sectorization based Pilot Assignment(CSS-PA)strategy to extenuate PC.In this strategy,making Signal to Interference plus Noise Ratio(SINR)as a basis,the users are first categorized into cell center and edge zones,followed by the subsequent sectorization of edge zones of each cell.Then,each cell center zone users are allotted with identical pilot sequences.On the other hand,for edge zone sectors,the appointed sequences are mutually orthogonal in different cells.With the assistance of mitigated PC,we have ascertained the approximate system capacity,which shows precision for the infinite number of cellular antennas at the BS.The outcome of simulation reveals that proposed CSS-PA strategy would effectively weaken PC.Moreover,the proposed idea has achieved higher system throughput,low Mean Square Error(MSE)and Normalized MSE(NMSE)at higher Signal to Noise Ratio(SNR)and maximum number of BS antennas in comparison to the traditional pilot sequences allocation strategy with the marked sequences reuse rate of one or three.