User admission for multi-user regenerative relay MIMO systems

We propose an efficient user admission method for multi-user regenerative relay multiple-input multiple-output (MIMO) systems with maximum sum rate system performance objective. We extend the relay system model proposed in [1] to manage multi-antenna user terminals. Our aim is to incorporate computationally efficient user admission into the conventional weighted sum rate maximization. To increase the rate of convergence and mitigate over-the-air signaling requirements, we make early predictions of the active set of spatial data streams, which effectively translates to user allocation. It is shown that the proposed method achieves close to optimal user allocation and greatly improves the performance at low signal-to-interference-plus-noise (SINR) region when compared to direct channel quality based user admission [1].