Optimal resource allocation for sensing based spectrum sharing cognitive radio networks

To improve the spectral efficiency of a cognitive radio system, sensing based spectrum sharing (SBSS) technique combines the advantages of spectrum overlay and spectrum underlay. In this paper, we study the performance of SBSS under primary users´ (PUs´) rate loss constraint. To be specific, efficient algorithms are introduced to find the optimal sensing time and power allocation in both single-carrier and multi-carrier systems. Performance evaluation is conducted to compare the system throughput between SBSS and spectrum overlay techniques. Simulation results suggest that SBSS outperforms spectrum overlay when the transmitter of the secondary user (SUT) is far away from the receiver of the primary user (PUR) in the single-carrier case. In the multi-carrier case, SBSS can achieve 15.2% increase of spectral efficiency over spectrum overlay when all the channel gains are independent and identically distributed.