Multiuser subcarrier and bit allocation for MIMO-OFDM systems with perfect and partial channel information

Abstract

Subcarrier and bit allocation schemes for SISO-OFDM systems in multiuser downlink scenario are well-documented. In this paper, we extend it to MIMO-OFDM systems and design a transmit scheme as a concatenation of dynamic subcarrier assignment, adaptive modulation and beamforming. With the goal of minimizing the overall transmit power required to meet the target BER, we develop an adaptive OFDM subcarrier allocation approach based on perfect and partial channel information. Simulation results show that our proposed algorithm outperforms the multiuser MIMO-OFDM with static FDMA technique considerably, and can lessen the performance loss caused by feedback delays. We have also evaluated the performance of the presented system under various number of transmit- and receive-antennas.