RESOURCE ALLOCATION IN MULTIUSER MIMO- OFDM SYSTEMS

Abstract

Multiple-input multiple-output (MIMO) wireless technology in combination with orthogonal frequency division multiplexing (MIMO-OFDM) is an attractive air-interface solution for next-generation wireless local area networks (WLANs), wireless metropolitan area networks (WMANs), and fourth-generation mobile cellular wireless systems because of their potential for high capacity, increased diversity, reduced receiver complexity and interference suppression. By doing proper resource allocation in MIMO-OFDM system, its capacity can be increased and system performance is also improved. Subcarriers are allocated to multiple users based on its channel state information. • In this thesis, we discuss power adaptation in multiuser OFDM system and its performance is compared with different subcarrier and power allocation schemes. Linear precoding technique for multiuser MIMO-OFDM system based on Block Diagonalization (BD) is also discussed which eliminates the co-channel interference. This report also discusses various dynamic resource allocation schemes for MIMO-OFDM system. Margin Adaptive (MA) resource allocation schemes minimizes the total transmitted power with constraint of the user's data rate while Rate Adaptive (RA) resource allocation schemes maximizes the sum rate of the system with constraint of user's transmit power. Margin adaptive and rate adaptive both solutions are obtained by using convex optimization and its performance are compared with different allocation schemes.