Joint Beamforming and Power Control to Overcome Tradeoff Between Throughput-Sensing in Cognitive Radio Networks

Cognitive radio is introduced for efficient spectrum utilization by allowing unlicensed (secondary) users to access licensed frequency bands and to maintain a minimum interference to the licensed (primary) users. A sensing time has been allocated for sensing the licensed frequency bands before data transmission of secondary system and during the sensing time, data transmission is prohibited, which results in the sensing throughput tradeoff problem. To overcome this tradeoff, the authors present join beamforming and power control approach in this paper. The presented modified WLS algorithm minimizes the interference to the primary system as well as overcome the sensing throughput tradeoff problems in cognitive radio. The simulation result shows that the optimal transmit power of secondary user can improve the system throughput.