Misbehavior detection in amplify-and-forward cooperative OFDM systems

The success of cooperative communications hinges on the reliability of cooperating nodes between the communicating parties, which may not be guaranteed in realistic scenarios. To protect cooperative networks from selfish misbehaviors and malicious forwarding, a security mechanism monitoring various abnormal behaviors during cooperation is necessary because of the constantly changing network topology and variability of cooperating nodes. In this paper, based on the orthogonal time division protocol commonly used in cooperation, a misbehavior detection scheme is proposed for amplify-and-forward (AF) cooperative orthogonal frequency division multiplexing (OFDM) systems by introducing the time division duplexing (TDD) feature into the source node and exploiting the correlation properties between the transmitted and received signals. With the estimated amplification gain and noise power, two binary hypothesis tests are employed to detect power-reducing selfish behaviors and malicious jamming attacks respectively. Simulation results demonstrate the effectiveness of the proposed scheme in detecting different misbehaviors of cooperating nodes.