Pilot Contamination Alleviation Scheme In Multi-Cell TDD Based Massive MIMO Systems

The rapid increase in mobile data traffic is considerable challenge for upcoming 5G cellular network.According to ongoing work,data traffic built up 69%in the year 2014,which indicates 30 times increase since 2000.It is projected that this demand will be more in upcoming decades.However,the current cellular network is uncapable to acquire high data rate and spectral efficiency.To meet the demand for high data rate and spectral efficiency,time division duplex(TDD)massive MIMO systems has been recognized as a promising technology which would need mounting of extensive number of antennas and users associated to the base stations(BSs).However,TDD mode is highly affected by pilot contamination(PC)which is caused by utilizing the same pilots9 sequences among the users in different cells.Thus,PC is a key problem in massive MIMO which highly degrade the system performance and needs to be investigated.lIn this dissertation,we projected a novel pilot assignment scheme"Efficient Sectorization-based Pilot Allocation(ES-PA)"to remarkably suppress PC and to enhance the SE of the system.According to this ES-PA scheme the users(UEs)are divided on the basis of their signal-to-interference-plus-noise ratios into two zones i.e.cell center and edge zones.Furthermore,the edge zone is partitioned into N uniform sectors by smart antenna techniques.After that,the UEs in the cell center zone in the entire system are assigned with identical pilot sequences due to less Inter-Cell Interference(ICI).Furthermore,the edge zone UEs in each sector are assigned with mutually orthogonal pilot sequences in different cells due to the higher ICI and to mitigate the PC.The simulation results make known that the projected algorithm has the efficiency to remarkably reduce PC,attains lower mean squared error and normalized MSE at greater SINR,higher data rate and better SE as compared to conventional pilot allocation techniques.