Performance evaluation of channel guard scheme for cognitive radio networks

Guard channel (GC) is a basic scheme to ensure the Quality of Service (QoS) of handoff users, especially for different QoS requirements of multimedia traffics. However, in the cognitive radio (CR) systems, the available channels the second users (SU) can use changed dynamically due to the arrival of primary user (PU), leading to a challenge of the traditional guard channel scheme. In this paper, the guard channel schemes for second users in CR networks are studied, and a new dynamical guard channel scheme is proposed. In the proposed approach, a generally theory analysis model with Markov chain is deduced, and the performance of different guard channel schemes including dynamical guard channel (DGC), without guard channel (NGC) and fixed guard channel (FGC) are evaluated. The numerical results show that the DGC can maintain relatively better performance according different network situations.