Overcoming the Sensing-Throughput Tradeoff in Cognitive Radio Networks

In a cognitive radio network that employs opportunistic spectrum access, the users are allowed to access a frequency band only when it is not being used by licensed users. Hence, spectrum sensing is of utmost importance, in order to efficiently exploit the unused spectrum and effectively protect the quality of service of licensed networks. For this reason, a time slot has been allocated for spectrum sensing at the beginning of each frame in the systems proposed so far. During this slot, data transmission is prohibited, which results in the sensing-throughput tradeoff problem. In this paper, we propose a novel cognitive radio system that overcomes the sensing-throughput tradeoff by performing spectrum sensing and data transmission at the same time, which maximizes both the sensing time and the throughput of the cognitive radio network. We introduce a novel receiver and frame structure for cognitive radio and analytically prove that the proposed cognitive radio system exhibits improved throughput and sensing capabilities. Finally, simulation results are provided to validate our theoretical analysis.