Presenter：Prof. Chong-Yung Chi
Presenter come from：Institute of Communications Engineering & Department of Electrical Engineering
National Tsing Hua University
Title：Secrecy Energy Efficiency in Cognitive Radio Networks with Untrusted Secondary Users
Abstract：The information security and energy efficiency in cognitive radio (CR) networks have been
extensively studied. However, the practical scenario involving multiple untrusted secondary users (SUs)
in CR networks under the underlay spectrum sharing mechanism has not been studied so far. This talk
considers the downlink secrecy energy efficient coordinated beamforming design for multiple inputs
single output CR networks under this scenario. Our goal is to maximize the global secrecy energy
efficiency (GSEE), defined as the ratio of the sum of secrecy rates of all the primary users (PUs) to the
total power consumption, under requirements on quality of service of Pus and SUs as well as
constraints on power budget at the primary transmitter (PTx) and the secondary transmitter (STx). To
tackle the non-convex GSEE maximization (GSEEM) problem, an algorithm is proposed based on
Dinkelbach method and successive convex approximation to jointly optimize beamforming vectors of
the PTx and the STx. The convergence behavior and the computational complexity of the proposed
GSEEM algorithm are analyzed, followed by the connection with the secrecy rate maximization design
and the power minimization (PM) design in terms of GSEE. In view of significantly higher
computational complexity of the proposed GSEEM algorithm than that of the PM design, a 2-step
searching scheme is further designed to efficiently search for an approximate solution to the considered
GSEEM problem based on the PM design and the golden search method. Simulation results
demonstrate the efficacy of the proposed GSEEM algorithm and the searching scheme, and show that
the spatial degrees of freedom (primarily determined by the antenna numbers of PTx and STx) is the
key factor to the performance of the proposed GSEEM algorithm.
Time：2021-3-3 14:00 (Wed.) / Place：M212
Tea Time：2021-3-3 13:30 (Wed.) / Tea Place：M104
Speaker profile：Invited Talk (Chi Abstract and Bio) (NTNU 2021-3-3)