Title: Power-Constrained Secrecy Rate Maximization for Joint Relay and Jammer Selection Assisted Wireless Networks,
Abstract: In this paper, we examine the physical layer security for cooperative
wireless networks with multiple intermediate nodes, where the
decode-and-forward (DF) protocol is considered. We propose a new joint relay
and jammer selection (JRJS) scheme for protecting wireless communications
against eavesdropping, where an intermediate node is selected as the relay for
the sake of forwarding the source signal to the destination and meanwhile, the
remaining intermediate nodes are employed to act as friendly jammers which
broadcast the artificial noise for disturbing the eavesdropper. We further
investigate the power allocation among the source, relay and friendly jammers
for maximizing the secrecy rate of proposed JRJS scheme and derive a
closed-form sub-optimal solution. Specificially, all the intermediate nodes
which successfully decode the source signal are considered as relay candidates.
For each candidate, we derive the sub-optimal closed-form power allocation
solution and obtain the secrecy rate result of the corresponding JRJS scheme.
Then, the candidate which is capable of achieving the highest secrecy rate is
selected as the relay. Two assumptions about the channel state information
(CSI), namely the full CSI (FCSI) and partial CSI (PCSI), are considered.
Simulation results show that the proposed JRJS scheme outperforms the
conventional pure relay selection, pure jamming and GSVD based beamforming
schemes in terms of secrecy rate. Additionally, the proposed FCSI based power
allocation (FCSI-PA) and PCSI based power allocation (PCSI-PA) schemes both
achieve higher secrecy rates than the equal power allocation (EPA) scheme.