Concurrent spectrum sensing and data transmission scheme in a CR system

We propose a spectrum-sensing and data-transmission scheme that utilizes multiple-input and multiple-output (MIMO) technology to enable the spectrum to be sensed and data to be transmitted simultaneously. By using our proposed scheme, the degradation of quality of service (QoS) that is caused by spectrum sensing can be reduced and the system throughput of a cognitive radio (CR) system can be increased, while the accuracy of the spectrum sensing is unaffected. Even the CR system transmits data during the spectrum sensing, the interference to a primary user which is caused by the CR system will not increase compared to a conventional scheme. We also analyze the performance of the proposed scheme in the presence of channel estimation errors. Through performance evaluations, we show that the proposed scheme can increase the throughput and QoS of CR systems.