7,632 research outputs found
Joint power allocation for DF concatenated MIMO successive relaying scheme under network power constraints
Power efficiency is a vital consideration in wireless system. In this paper, we propose a framework for efficient power allocation in decode and forward multiple input multiple output successive relaying systems under network power constraints. Our aim is to maximize the information rate at each link by an optimal power allocation scheme via the primal dual algorithm. Then, we jointly allocate power to the source and transmitting relay under network power constraints. The simulated results show that the proposed joint power allocation scheme under network power constraint can outperform the uniform power allocation under an aggregate power constraints
Full-Duplex Wireless-Powered Relay with Self-Energy Recycling
This letter studies a wireless-powered amplify-and-forward relaying system,
where an energy-constrained relay node assists the information transmission
from the source to the destination using the energy harvested from the source.
We propose a novel two-phase protocol for efficient energy transfer and
information relaying, in which the relay operates in full-duplex mode with
simultaneous energy harvesting and information transmission. Compared with the
existing protocols, the proposed design possesses two main advantages: i) it
ensures uninterrupted information transmission since no time switching or power
splitting is needed at the relay for energy harvesting; ii) it enables the
so-called self-energy recycling, i.e., part of the energy (loop energy) that is
used for information transmission by the relay can be harvested and reused in
addition to the dedicated energy sent by the source. Under the multiple-input
single-output (MISO) channel setup, the optimal power allocation and
beamforming design at the relay are derived. Numerical results show a
significant throughput gain achieved by our proposed design over the existing
time switching-based relay protocol.Comment: 10 pages, 5 figure
Energy-efficiency for MISO-OFDMA based user-relay assisted cellular networks
The concept of improving energy-efficiency (EE) without sacrificing the service quality has become important nowadays. The combination of orthogonal frequency-division multiple-access (OFDMA) multi-antenna transmission technology and relaying is one of the key technologies to deliver the promise of reliable and high-data-rate coverage in the most cost-effective manner. In this paper, EE is studied for the downlink multiple-input single-output (MISO)-OFDMA based user-relay assisted cellular networks. EE maximization is formulated for decode and forward (DF) relaying scheme with the consideration of both transmit and circuit power consumption as well as the data rate requirements for the mobile users. The quality of-service (QoS)-constrained EE maximization, which is defined for multi-carrier, multi-user, multi-relay and multi-antenna networks, is a non-convex and combinatorial problem so it is hard to tackle. To solve this difficult problem, a radio resource management (RRM) algorithm that solves the subcarrier allocation, mode selection and power allocation separately is proposed. The efficiency of the proposed algorithm is demonstrated by numerical results for different system parameter
Diversity-Multiplexing Tradeoffs in MIMO Relay Channels
A multi-hop relay channel with multiple antenna terminals in a quasi-static
slow fading environment is considered. For both full-duplex and half-duplex
relays the fundamental diversity-multiplexing tradeoff (DMT) is analyzed. It is
shown that, while decode-and-forward (DF) relaying achieves the optimal DMT in
the full-duplex relay scenario, the dynamic decode-and-forward (DDF) protocol
is needed to achieve the optimal DMT if the relay is constrained to half-duplex
operation. For the latter case, static protocols are considered as well, and
the corresponding achievable DMT performance is characterized.Comment: To appear at IEEE Global Communications Conf. (Globecom), New
Orleans, LA, Nov. 200
- …