Throughput optimisation in sensor network-aided cognitive radio
Ishrat Maherin, Qilian Liang · International Journal of Sensor Networks · 2013
One of the biggest challenges in cognitive radio (CR) network is to maximise the throughput of the secondary user while keeping the interference to the primary under the interference threshold. Efficient spectrum sensing along with transmit power control can achieve this conflicting goal. In this paper, we propose a sensor network aided cognitive radio system which will reduce the missed detection and reduce the interference. We investigate the performance of various sensing and power allocation schemes for an OFDM–based cognitive radio system. We formulate an optimisation problem to design the optimal sensing time and transmit power. Mathematical analysis shows that interference between primary and secondary in OFDM–based system depends on spectral distance. Results show that distance dependent modified water filling (DDMWF) scheme can achieve the highest data rate for the cognitive radio based secondary user and then the optimal sensing time can be designed to maximise the throughput.