Secure transmission power of cognitive radios for dynamic spectrum access applications

One of the major concerns of cognitive radios when used for secondary spectrum access is the potential of interfering primary users, considering especially that cognitive radios may be misbehaved or under malicious attacks. In this paper, we present a method for a cognitive radio to secure its transmission power purely from its physical-layer received signals. Built into the transceiver hardware as an independent self-check procedure, this method can guarantee the avoidance of excessive interference of cognitive radios to primary users even when the more flexible upper-layer software or policy regulator is compromised under attacks. Analysis and simulations show that the secure transmission power determined by this procedure can be very close to the ideal secondary transmission power in many practical situations, so the proposed method is helpful to guarantee both the efficiency and the security of cognitive radios.