4 research outputs found
Artificial-Noise-Aided Secure Multi-Antenna Transmission with Limited Feedback
We present an optimized secure multi-antenna transmission approach based on
artificial-noise-aided beamforming, with limited feedback from a desired
single-antenna receiver. To deal with beamformer quantization errors as well as
unknown eavesdropper channel characteristics, our approach is aimed at
maximizing throughput under dual performance constraints - a connection outage
constraint on the desired communication channel and a secrecy outage constraint
to guard against eavesdropping. We propose an adaptive transmission strategy
that judiciously selects the wiretap coding parameters, as well as the power
allocation between the artificial noise and the information signal. This
optimized solution reveals several important differences with respect to
solutions designed previously under the assumption of perfect feedback. We also
investigate the problem of how to most efficiently utilize the feedback bits.
The simulation results indicate that a good design strategy is to use
approximately 20% of these bits to quantize the channel gain information, with
the remainder to quantize the channel direction, and this allocation is largely
insensitive to the secrecy outage constraint imposed. In addition, we find that
8 feedback bits per transmit antenna is sufficient to achieve approximately 90%
of the throughput attainable with perfect feedback.Comment: to appear in IEEE Transactions on Wireless Communication
On–Off-Based Secure Transmission Design With Outdated Channel State Information
We design new secure on-off transmission schemes
in wiretap channels with outdated channel state information
(CSI). In our design we consider not only the outdated CSI from
the legitimate receiver but two distinct scenarios, depending on
whether or not the outdated CSI from the eavesdropper is known
at the transmitter. Under this consideration our schemes exploit
the useful knowledge contained in the available outdated CSI,
based on which the transmitter decides whether to transmit or
not. We derive new closed-form expressions for the transmission
probability, the connection outage probability, the secrecy outage
probability, and the reliable and secure transmission probability
to characterize the achievable performance. Based on these
results, we present the optimal solutions that maximize the
secrecy throughput under dual connection and secrecy outage
constraints. Our analytical and numerical results offer detailed
insights into the design of the wiretap coding parameters and
the imposed outage constraints. We further show that allowing
more freedom on the codeword transmission rate enables a larger
feasible region of the dual outage constraints by exploiting the
trade-off between reliability and security.ARC Discovery Projects Grant DP15010390