Channel sharing in cognitive radio networks

In this paper, we consider a cognitive radio network in which the secondary users are allowed to share the spectrum with the primary users as long as the interference caused by the secondary users to the primary users is below a specified level. Both the primary users and secondary users access the common channel by way of transmission schedules. The channel model includes realistic features such as receiver noise, fading, and multiuser interference. Our primary performance measure is network throughput, which is the average number of packets that are successfully received per time slot. For a given level of guaranteed performance for each primary user, our goal is to determine the transmission schedule for the secondary users that maximizes their throughput. Our method exploits the multi-packet reception capability to improve throughput performance. We show that our method for scheduling can allow significant additional throughput for the secondary users, while keeping the impact of interference to the primary users to the specified level.