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Adaptive Equalizer with Reduced Computational Complexity for Improved Capacity and Ergodic Rate in OFDM-MIMO System

Manoj Kumar Das, D. Raj Veerappa

Abstract


A wireless channel model can be considered both as a time-domain and frequency-domain channel with stationary and ergodic features. As a time-domain channel it is complex normal and independent across filter taps and users. Similarly in frequency-domain it has correlated channel gains across subcarriers. In this context, in this paper, anticipative models where decisions are made based on the distribution and the actual realizations of the random quantities (adaptive models) are presented for MIMO system. A novel premodulation filter and adaptive code synchronization scheme is discussed. Multistage recourse models with non-anticipative action for the 1st stage and recourse actions for the 2nd stage based on the realization of the random quantities are presented. The work shall assist in improved definitive prioritization among users and can trace boundary of capacity region with specified ratio. The proposed algorithms are adaptive with low complexity and more suited for online processing.


Keywords


Multi-input/Multi-Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Decision Feedback Equalizer (DFE), Adaptive Code Synchronization

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References


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