1 research outputs found
Improving Secrecy with Nearly Collinear Main and Wiretap Channels via a Cooperative Jamming Relay
In physical layer security (PHY-security), the frequently observed high
correlation between the main and wiretap channels can cause a significant loss
of secrecy. This paper investigates a slow fading scenario, where a transmitter
(Alice) sends a confidential message to a legitimate receiver (Bob) while a
passive eavesdropper (Eve) attempts to decode the message from its received
signal. It is assumed that Alice is equipped with multiple antennas while Bob
and Eve each have a single antenna (i.e., a MISOSE system). In a MISOSE system,
high correlation results in nearly collinear main and wiretap channel vectors,
which help Eve to see and intercept confidential information. Unfortunately,
the signal processing techniques at Alice, such as beamforming and artificial
noise (AN), are helpless, especially in the extreme case of completely
collinear main and wiretap channel vectors. On this background, we first
investigate the achievable secrecy outage probability via beamforming and AN at
Alice with the optimal power allocation between the information-bearing signal
and AN. Then, an ingenious model, in which a cooperative jamming relay (Relay)
is introduced, is proposed to effectively mitigate the adverse effects of high
correlation. Based on the proposed model, the power allocation between the
information-bearing signal at Alice and the AN at Relay is also studied to
maximize secrecy. Finally, to validate our proposed schemes, numerical
simulations are conducted, and the results show that a significant performance
gain with respect to secrecy is achieved