Load control for multi-stage interference cancellation

Multi-stage interference cancellation (IC) can improve the interference conditions for all users of a cell. In order to exploit the IC gain at system level, it is important to design radio resource management algorithms that account for this gain. For this purpose, two new load control algorithms are proposed in this paper, together with some further enhancements. For Algorithm 1, load control and scheduling are still performed based on the air interface Rise over Thermal (RoT), but with an increased RoT target. The RoT target is determined based on the estimated IC gain. A cell-specific and dynamic RoT target is hence used rather than a constant one. With Algorithm 2, load control and scheduling are performed based on an effective RoT without increasing the RoT target. The load control function is placed after an intermediate IC stage depending on the timing constraints and/or the required IC processing gain of the coverage limiting channels. With the proposed algorithms, system-level simulation results show that the average cell throughput can be considerably improved and at the same time the coverage can be maintained at a level similar to a system without IC.