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MMSE-CoSaMP Compressive Sensing Based Multi-User Detection For Uplink Grant Free NOMA System

Posted on:2020-03-18Degree:MasterType:Thesis
Country:ChinaCandidate:Ghulam AbbasFull Text:PDF
GTID:2428330590961618Subject:Electronic and computer engineering
Abstract/Summary:PDF Full Text Request
The main challenges for massive wireless communication in 5G system are to support random access for massive users and to control signaling overhead and data processing complexity.Non-Orthogonal Multiple Access(NOMA)is the most prominent technology that enhances massive connectivity and spectral efficiency in 5G cellular communication by utilizing the power domain and Advance receiver.It provides services to the multi-users in time,frequency and code domain with significant power level.Message Passing Algorithm(MPA)detection in multi-user uplink grant-free system requires user activity information at receiver that makes it impractical because in Uplink grant-free System user can randomly enter or leave the system without giving the information to the Base Station(BS).To circumvent this problem,MPA is jointly used with Compressive Sampling Matching Pursuit(CoSaMP)based detection which not only detects the user activity but also the signal data.The most difficult task is to find the position of the non-zero data for mapping the non-zero elements effectively,CoSaMP is used,its complexity is lower as compare to others and excellent robustness to noise,so that the user activity can be detected with high accuracy.In CoSaMP,the strongest components of the original sparse signal are identified in an iterative manner,However,Compressive Sampling Matching pursuit(CoSaMP)algorithm uses Zero forcing(ZF)detector to estimate the signal but its performance degrades with increasing Signal to Noise Ratio(SNR)because the ZF has drawback to enhancement of the noise.Therefore,Minimum Mean Square Error(MMSE)detector in CoSaMP algorithm is deployed because MMSE decrease mean error in this Thesis that enhances detection accuracy and Bit Error Rate(BER)performance.The simulation results validate that proposed algorithm attains better performance than MPA and conventional CoSaMP algorithm in high SNR.
Keywords/Search Tags:MMSE, multi-user Detection, Compressive Sensing, Sparse Signal, NOMA
PDF Full Text Request
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