Secrecy rate and residual energy trade-off in energy harvesting cognitive radio networks

Abstract

Secrecy rate and residual energy are the critical criteria of performance evaluation for energy harvesting cognitive radio (EHCR) networks. However, these two criteria are conflicting. This paper commits to investigating the trade-off between the secrecy rate of primary transmitter and residual energy of secondary transmitter in EHCR networks. The trade-off is formulated as an optimization problem based on nonlinear programming. A polynomial-time algorithm is proposed to achieve the approximate solution for the trade-off problem, by searching the feasible values of secrecy rate and residual energy between the lower bound and upper bound of transmission power. Moreover, we prove that there is negative correlation between the secrecy rate of primary transmitter and residual energy of secondary transmitter. Simulation results show that the proposed computing model outperforms the standard cooperative communication model by 48.12%, 85.58%, and 132.34% averagely in terms of the secrecy rate of primary transmitter, for the transmission powers of 1.4W, 1.5W and 1.6W, respectively, without suffering from low performance in terms of residual energy of secondary transmitter.