Resource Allocation for Collaborative Secondary Usage of Interfering Multiple Access Primary Channel by a Selective Relay

This letter investigates resource allocation in order to exploit a collaborative secondary usage of interfering multiple access primary channel (MAPC) by a selective relay as a secondary user (SU). We optimally allocate transmit power and time slot so that SU (i.e., the relay) could achieve a maximum data rate while the primary data rates are not degraded at all as if they were without the secondary intervention. Numerical investigation is used to verify the optimality of the proposed resource allocation and to show where the investigated secondary usage is feasible. It is also shown that the proposed usage can provide the sum-rate improvement up to 153-195% compared to the primary only system.