Interference-Aware Subcarrier Allocation in a Correlated MIMO Downlink Transmission

The demand for high data rate in wireless communication has increased dramatically over the last two decades. Multiple-Input Multiple-Output (MIMO) transmission is one of the efficient ways to transmit high data rate is by employing multiple antenna configuration at both the transmitter and the receiver. One of the MIMO scheme, known as Spatial Multiplexing (SM), relies on the linear independence data streams from different transmit antennas to exploit the capacity from the fading channels. Consequently, SM suffers considerably from the effect of spatial correlation, thus becomes the limiting factor in achieving the capacity benefit that SM offers. In an attempt to increase the robustness of the SM transmission for deployment in a wide range of correlated channels, the use of interference-aware subcarrier allocation is proposed. The Signalto-Interference-and-Noise Ratio (SINR) metric is used as the performance metric to determine subcarrier quality which can then be utilized in the allocation process in order to exploit the multiuser diversity gain that can be offered in an Orthogonal Frequency Division Multiple Access (OFDMA) system. From the simulation results, it is shown that the proposed subcarrier allocation has improved the BER performance of SM transmission in highly correlated channels environment. Key-Words: Correlated channel, SINR, Interference, MIMO, OFDMA, Spatial multiplexing, Spatial correlation, Subcarrier allocation