Enhanced outage performance with adaptive linear precoding in cognitive radio downlink

In this paper, we investigate the outage performance of interference aided adaptive linear precoding in the downlink of a multiuser multiple-input-single-output (MISO) overlay cognitive radio (CR) network. While previous research studies on linear precoding techniques in CR network aim to limit or completely cancel the interference to the primary users while achieving maximum downlink throughput of the CR system, we here make use of adaptive linear precoding at the cognitive base station (CBS) to exploit the interference to the primary and the secondary systems. We show by analysis and simulations that the outage performance of the proposed precoding technique is significantly enhanced in comparison to the conventional techniques.