947 research outputs found
Rate Balancing in Full-Duplex MIMO Two-Way Relay Networks
Maximizing the minimum rate for a full-duplex multiple-input multiple-output
(MIMO) wireless network encompassing two sources and a two-way (TW) relay
operating in a two hop manner is investigated. To improve the overall
performance, using a zero-forcing approach at the relay to suppress the
residual self-interference arising from full-duplex (FD) operation, the
underlying max-min problem is cast as an optimization problem which is
non-convex. To circumvent this issue, semidefinite relaxation technique is
employed, leading to upper and lower bound solutions for the optimization
problem. Numerical results verify that the upper and lower bound solutions
closely follow each other, showing that the proposed approach results in a
close-to-optimal solution. In addition, the impact of residual
self-interference upon the overall performance of the network in terms of the
minimum rate is illustrated by numerical results, and for low residual
self-interference scenarios the superiority of the proposed method compared to
an analogous half-duplex (HD) counterpart is shown
Throughput Analysis and Optimization of Wireless-Powered Multiple Antenna Full-Duplex Relay Systems
We consider a full-duplex (FD) decode-and-forward system in which the
time-switching protocol is employed by the multi-antenna relay to receive
energy from the source and transmit information to the destination. The
instantaneous throughput is maximized by optimizing receive and transmit
beamformers at the relay and the time-split parameter. We study both optimum
and suboptimum schemes. The reformulated problem in the optimum scheme achieves
closed-form solutions in terms of transmit beamformer for some scenarios. In
other scenarios, the optimization problem is formulated as a semi-definite
relaxation problem and a rank-one optimum solution is always guaranteed. In the
suboptimum schemes, the beamformers are obtained using maximum ratio combining,
zero-forcing, and maximum ratio transmission. When beamformers have closed-form
solutions, the achievable instantaneous and delay-constrained throughput are
analytically characterized. Our results reveal that, beamforming increases both
the energy harvesting and loop interference suppression capabilities at the FD
relay. Moreover, simulation results demonstrate that the choice of the linear
processing scheme as well as the time-split plays a critical role in
determining the FD gains.Comment: Accepted for publication in IEEE Transactions on Communication
Massive MIMO Full-Duplex Relaying with Optimal Power Allocation for Independent Multipairs
With the help of an in-band full-duplex relay station, it is possible to
simultaneously transmit and receive signals from multiple users. The
performance of such system can be greatly increased when the relay station is
equipped with a large number of antennas on both transmitter and receiver
sides. In this paper, we exploit the use of massive arrays to effectively
suppress the loopback interference (LI) of a decode-and-forward relay (DF) and
evaluate the performance of the end-to-end (e2e) transmission. This paper
assumes imperfect channel state information is available at the relay and
designs a minimum mean-square error (MMSE) filter to mitigate the interference.
Subsequently, we adopt zero-forcing (ZF) filters for both detection and
beamforming. The performance of such system is evaluated in terms of bit error
rate (BER) at both relay and destinations, and an optimal choice for the
transmission power at the relay is shown. We then propose a complexity
efficient optimal power allocation (OPA) algorithm that, using the channel
statistics, computes the minimum power that satisfies the rate constraints of
each pair. The results obtained via simulation show that when both MMSE
filtering and OPA method are used, better values for the energy efficiency are
attained.Comment: Accepted to the 16th IEEE International Workshop on Signal Processing
Advances in Wireless Communications - SPAWC, Stockholm, Sweden 201
- …