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This paper deals with an Orthogonal Frequency Division Multiplexing (OFDM)-based uplink within a Multi User (MU)-Multi-Input Multi-Output (MIMO) system where a ”massive MIMO” approach” is adopted. In this context, either an optimum Minimum Mean-Squared Error (MMSE) linear detection or a reduced-complexity Matched Filter (MF) linear detection are considered. Regarding performance evaluation by simulation, several semi-analytical methods are proposed: one performance evaluation method in the optimum (MMSE) case; two performance evaluation methods in the MF case. This paper includes performance results for uncoded 4-Quadrature Amplitude Modulation (QAM)/OFDM transmission and a MUMIMO channel with uncorrelated Rayleigh fading, under the assumptions of perfect power control and perfect channel estimation. The accuracy of performance results obtained through the semi-analytical simulation methods is assessed by means of parallel conventional Monte Carlo simulations [10]. The performance resultsare discussed indetail andwe also emphasize the achievable ”massive MIMO” effects, even for the reducedcomplexity detection techniques, provided that the number of BS antennas is much higher than the number of antennas which are jointly employed in the terminals of the multiple autonomous users.

This paper deals with Single Carrier (SC)/Frequency Domain Equalization (FDE) as an uplink alternative to Orthogonal Frequency Division Multiplexing (OFDM) for a Multi User (MU)-Multi-Input Multi-Output (MIMO) system where a ”massive MIMO” approach is adopted. In this context, either an optimum Minimum Mean-Squared Error (MMSE) linear detector or appropriate reduced-complexity linear detection techniques are considered. Regarding performance evaluation by simulation, two semi-analytical methods are proposed - one method in the optimum (MMSE) case and the other one in the reduced-complexity cases. This paper includes performance results for uncoded 4 Quadrature Amplitude Modulation (QAM) SC/FDE transmission and a MU-MIMO channel with uncorrelated Rayleigh fading, under the assumptions of perfect power control and perfect channel estimation.The accuracy of performance results obtained through the semi-analytical simulation methods is assessed by means of parallel conventional Monte Carlo simulations. The performance results are discussed in detail and we also emphasize the achievable ”massive MIMO” effects, even for the reduced complexity detection techniques, provided that the number of BS antennas is much higher than the number of antennas which are jointly employed in the terminals of the multiple autonomous users. Appropriate ”SC/FDE vs OFDM” comparisons are also included in this discussion of performance results.

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This paper deals with CP-assisted block transmissionsolutionsforfuturemobilebroadbandsystems,inthecontext of a Single Carrier (SC)-Frequency Division Multiple Access (FDMA)uplink.Twoalternativechoicesareconsideredregarding the subcarrier mapping rule: a ”localized” subcarrier mapping where user’s data occupy a set of consecutive sub carriers (Rule 1); a ”distributed” subcarrier mapping where user’s data occupy a set of uniformly spaced subcarriers (Rule 2). Detailed performance evaluations, in this paper, involve the consideration of two iterative receiver techniques which can be regarded as extensions of iterative receiver techniques proposed previously within a single user context. A selected class of multipath radio channels, providing a range of channel time dispersion levels, is assumed for performance evaluation purposes,andasetofmatchedfilterboundsonreceiverperformance plays a relevant role in ”achievable performance” comparisons. Both the impact of the mapping rules and that of the iterative receiver techniques considered here are evaluated in detail. The performance advantages under ”Rule 2” are emphasized, for practically the entire range of the channel time dispersion levels assumed in the paper and both specific iterative receiver techniques.