Maximum Throughput for a Cognitive Radio Multi-Antenna User with Multiple Primary Users

We investigate a cognitive radio scenario involving a single cognitive transmitter equipped with K antennas sharing the spectrum with M primary users (PUs) communicating with their respective receivers. Each terminal has a queue to store its incoming traffic. We propose a novel protocol where the cognitive user transmits its packet over a channel formed by the aggregate of the inactive (empty) primary bands. We study the impact of the number of the PUs, the sensing errors, and the number of antennas on the maximum secondary stable throughput.