An Opportunistic Spectrum Scheduling Scheme for Multi-Channel Cognitive Radio Networks

In this paper, we develop an opportunistic spectrum scheduling scheme for cognitive radio networks. In the proposed scheme, the channel status (i.e., whether being occupied by primary users) and the instantaneous channel quality (SNR at the secondary receiver) are assumed to vary fast within a frame which consists of a fixed number of slots. At each scheduling epoch, each secondary user will observe the channel conditions, namely the channel status and the channel quality. Based on the queue size and the observed channel conditions, each secondary user will estimate the throughput for each channel over the frame to be scheduled. A scheduling algorithm is performed to maximize the expected aggregate throughput of all the secondary users. The performances of the proposed scheduling scheme in terms of throughput and percentage of packet drop are evaluated.