PERFORMANCE ANALYSIS AND OPTIMIZATION OF AN ENERGY-SAVING STRATEGY WITH SLEEP MODE IN COGNITIVE RADIO NETWORKS

摘要

In cognitive radio networks, a great deal of energy is wasted when the base station becomes idle. To solve this problem, we propose an energy-saving strategy with the sleep mode in this paper. Considering that primary user packets can interrupt the transmission of secondary user packets at any time and occupy the spectrum with pre-emptive priority, we establish a two-dimensional continuous-time Markov chain model to capture the stochastic behavior of the network. Moreover, we obtain the stable condition of the system, and then we derive the expressions for the performance measures in terms of energy-saving rate of system and average latency of secondary user packets. Numerical results with analysis as well as simulation show that the equilibrium arrival rate of SU packets is always greater than the socially optimal arrival rate of SU packets. Based on this observation, we present a pricing policy to optimize the system performance socially.