Blind and robust spectrum sensing based on RF impairments mitigation for cognitive radio receivers

摘要

The smart behavior of cognitive receivers is based on an efficient spectrum sensing, leading to an opportunistic use of vacant resources. Therefore, an error-free detection of spectrum white spaces is required to enable all the adaptive functionalities of cognitive radios. Practically, the RF tunable frontend is a source of various RF impairments that harm the accuracy of sensing techniques. On the other hand, noise and channel uncertainty in real environments could also deteriorate the sensing accuracy. In this paper, we present an enhanced blind and robust spectrum sensing algorithm based on two modules i.e. mitigation and sensing. The proposed scheme overcomes main sensing challenges such as model uncertainty and hardware imperfections. To demonstrate the efficiency of this technique, realworld measurements using USRP N210 are presented and discussed. Received signals are observed, before and after mitigation, highlighting the cancellation of unwanted frequency components induced by RF nonlinearities. The decreased probability of false alarm is calculated to highlight the enhanced detection efficiency.