Title: Block diagonalisation with adaptive resource allocation algorithm for multi-user MIMO-OFDM systems

Authors: K. Gunaseelan, P. Reba, A. Kandaswamy

Addresses: Department of Electronics and Communication Engineering, PSG College of Technology, Peelamedu, Coimbatore – 641 004, Tamil Nadu, India. ' Department of Electronics and Communication Engineering, PSG College of Technology, Peelamedu, Coimbatore – 641 004, Tamil Nadu, India. ' Department of Biomedical Engineering, PSG College of Technology, Peelamedu, Coimbatore – 641 004, Tamil Nadu, India

Abstract: The challenging issue in multi-user MIMO-OFDM system is to cancel multi-access interference (MAI) when different users share the same subcarrier. Also, the presence of MAI makes the resource allocation problem very complicated. Hence it is essential to find the optimal transmit and receive weight vectors, to reduce MAI and to adaptively assign resources to meet the quality of service (QoS) requirements. In this paper, block diagonalisation (BD) with waterfilling power allocation is considered and analysed their performance. This BD with waterfilling power allocation algorithm increases the system capacity with zero MAI. In order to have further increase in system performance, the proposed method considers rate adaptation scheme and margin adaptation scheme. In rate adaptation technique BD with power and subcarrier allocation is performed to maximise the system capacity. In margin adaptation technique BD with power and bit allocation is done to improve QoS of the system. The simulation results show that there is significant improvement in system performance also guaranteeing zero MAI.

Keywords: multiple-input multiple-output; MIMO; orthogonal frequency division multiplexing; OFDM; multi-access interference; MAI; adaptive resource allocation; margin adaptation; rate adaptation; block diagonalisation; quality of service; QoS; sum capacity; bit error rate.

DOI: 10.1504/IJUWBCS.2009.026450

International Journal of Ultra Wideband Communications and Systems, 2009 Vol.1 No.1, pp.58 - 66

Published online: 11 Jun 2009 *

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