On the Performance of Limited Feedback Single-/Multi-User MIMO in 3GPP LTE Systems

In cellular wireless communications standard bodies (e.g., 3GPP, 3GPP2), multiple-input multiple-output (MIMO) transmission techniques have been one of long lasting issues for its standardization. Recently, 3GPP launched multi-carrier based beyond 3G study item (i.e., long-term evolution or LTE) to compete with other solutions such as IEEE 802.16e/20. In LTE or other compatible systems, feedback overhead is a key factor for throughput enhancement. The choice between single- user and multi-user MIMO is equivalently aligned with the problem of feedback burden, while throughput maximization is still of major concern in both scenarios. In this paper, we investigate the throughput performances of those two MIMO modes based on orthogonal frequency division multiple access (OFDMA) framework in LTE. Simulation results show that multi-user MIMO scheme is more favorable than single-user MIMO in terms of receiver complexity and throughput gain, assuming that feedback overhead is almost equally allowed (i.e., additional 1-bit feedback is required for preceding in multi-user MIMO).