4,228 research outputs found
Optimal Power Allocation for A Massive MIMO Relay Aided Secure Communication
In this paper, we address the problem of optimal power allocation at the
relay in two-hop secure communications under practical conditions. To guarantee
secure communication during the long-distance transmission, the massive MIMO
(M-MIMO) relaying techniques are explored to significantly enhance wireless
security. The focus of this paper is on the analysis and design of optimal
power assignment for a decode-and-forward (DF) M-MIMO relay, so as to maximize
the secrecy outage capacity and minimize the interception probability,
respectively. Our study reveals the condition for a nonnegative the secrecy
outage capacity, obtains closed-form expressions for optimal power, and
presents the asymptotic characteristics of secrecy performance. Finally,
simulation results validate the effectiveness of the proposed schemes
Energy-Efficient Optimization for Wireless Information and Power Transfer in Large-Scale MIMO Systems Employing Energy Beamforming
In this letter, we consider a large-scale multiple-input multiple-output
(MIMO) system where the receiver should harvest energy from the transmitter by
wireless power transfer to support its wireless information transmission. The
energy beamforming in the large-scale MIMO system is utilized to address the
challenging problem of long-distance wireless power transfer. Furthermore,
considering the limitation of the power in such a system, this letter focuses
on the maximization of the energy efficiency of information transmission (bit
per Joule) while satisfying the quality-of-service (QoS) requirement, i.e.
delay constraint, by jointly optimizing transfer duration and transmit power.
By solving the optimization problem, we derive an energy-efficient resource
allocation scheme. Numerical results validate the effectiveness of the proposed
scheme.Comment: 4 pages, 3 figures. IEEE Wireless Communications Letters 201
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