A spatial interference minimization strategy for the correlated LTE downlink channel

In a downlink transmission, users can benefit from the high capacity gain achieved by transmitting independent data streams from multiple antennas to multiple users sharing the same physical time-frequency resources. This technique is known as multiuser MIMO (MU-MIMO). However, performance of MU-MIMO is sensitive towards propagation imperfections, such as time dispersion and inter-stream interference due to antenna correlation. In this paper we investigate the performance of MU-MIMO operation in 3GPP-LTE downlink transmission by employing a novel multiuser allocation, known as dynamic subcarrier allocation (DSA) that aims to minimize the effect of antenna correlation from the knowledge of the Effective Signal-to-Interference-plus-Noise Ratio (ESINR) metric. The suboptimal scheme is especially attractive when the number of users is large in highly correlated channel conditions where it is able to minimize the effect of spatial correlation and thereby achieve improved BER performance.