Robust and secure spectrum sensing in cognitive radio networks
Changlong Chen · OhioLink ETD Center (Ohio Library and Information Network) · 2013
With wireless devices and applications booming, the problem of inefficient utilization of the precious radio spectrum has arisen.Cognitive radio is a key technology to improve spectrum utilization.A major challenge in cognitive radio networks is spectrum sensing, which detects if a spectrum band is being used by a primary user.Spectrum sensing plays a critical role in cognitive radio networks.However, spectrum sensing is vulnerable to security attacks from malicious users.Detecting malicious users is a crucial problem for cognitive radio networks.First, the channel shadowing and fading result in spatial variability and uncertainty of the PU signal, and hence the sensing reports among geographically separated secondary users are usually distinct.This makes it easy for malicious users to hide the dishonest sensing reports under the natural variation of the sensing reports.Second, due to the open and easy reconfiguration nature of cognitive radio, the cognitive radios are more prone to be compromised and, once compromised, they are prone to more diverse misbehavior.This makes the malicious user detection more difficult than finding faulty or misconfigured users whose effects on the cognitive radio networks are more evident and easy to predict.We propose a decentralized scheme to detect malicious users in cooperative spectrum sensing.The scheme utilizes spatial correlation of received signal strengths among secondary users in close proximity.We also propose to use an alternative iii I would never have been able to finish my dissertation without the guidance, support, and help from numerous people.Firstly, I would like to express my deepest gratitude to my advisor, Dr.