272 research outputs found
Outage Capacity of Bursty Amplify-and-Forward with Incremental Relaying
We derive the outage capacity of a bursty version of the amplify-and-forward
(BAF) protocol for small signal-to-noise ratios when incremental relaying is
used. We show that the ratio between the outage capacities of BAF and the
cut-set bound is independent of the relay position and that BAF is outage
optimal for certain conditions on the target rate R. This is in contrast to
decode-and-forward with incremental relaying, where the relay location strongly
determines the performance of the cooperative protocol. We further derive the
outage capacity for a network consisting of an arbitrary number of relay nodes.
In this case the relays transmit in subsequent partitions of the overall
transmission block and the destination accumulates signal-to-noise ratio until
it is able to decode.Comment: 5 pages, 3 figures, submitted to IEEE International Symposium on
Information Theory, Austin, TX, June 13-18, 201
On the Performance of the Relay-ARQ Networks
This paper investigates the performance of relay networks in the presence of
hybrid automatic repeat request (ARQ) feedback and adaptive power allocation.
The throughput and the outage probability of different hybrid ARQ protocols are
studied for independent and spatially-correlated fading channels. The results
are obtained for the cases where there is a sum power constraint on the source
and the relay or when each of the source and the relay are power-limited
individually. With adaptive power allocation, the results demonstrate the
efficiency of relay-ARQ techniques in different conditions.Comment: Accepted for publication in IEEE Trans. Veh. Technol. 201
TAS-Based Incremental Hybrid Decode–Amplify–Forward Relaying for Physical Layer Security Enhancement
In this paper, a transmit antenna selection (TAS)-
based incremental hybrid decode-amplify-forward (IHDAF)
scheme is proposed to enhance physical layer security in cooperative
relay networks. Specifically, TAS is adopted at the
source in order to reduce the feedback overhead. In the proposed
TAS-based IHDAF scheme, the network transmits signals to the
destination adaptive select direction transmission mode, AF mode
or DF mode depending on the capacity of the source-relay link
and source-relay link. In order to fully examine the benefits
of the proposed TAS-based IHDAF scheme, we first derive its
secrecy outage probability (SOP) in a closed-form expression. We
then conduct asymptotic analysis on the SOP, which reveals the
secrecy performance floor of the proposed TAS-based IHDAF
scheme when no channel state information is available at the
source. Theoretical analysis and simulation results demonstrate
that the proposed TAS-based IHDAF scheme outperforms the
selective decode-and-forward (SDF), the incremental decodeand-forward
(IDF), and the noncooperative direction transmission
(DT) schemes in terms of the SOP and effective secrecy
throughout, especially when the relay is close to the destination.
Furthermore, the proposed TAS-based IHDAF scheme offer a
good trade-off between complexity and performance compare
with using all antennas at the source.ARC Discovery Projects Grant DP150103905
A Study Of Cooperative Spectrum Sharing Schemes For Internet Of Things Systems
The Internet of Things (IoT) has gained much attention in recent years with the massive increase in the number of connected devices. Cognitive Machine-to-Machine (CM2M) communications is a hot research topic in which a cognitive dimension allows M2M networks to overcome the challenges of spectrum scarcity, interference, and green requirements. In this paper, we propose a Generalized Cooperative Spectrum Sharing (GCSS) scheme for M2M communication. Cooperation extends the coverage of wireless networks as well as increasing their throughput while reducing the energy consumption of the connected low power devices. We study the outage performance of the proposed GCSS scheme for M2M system and derive exact expressions for the outage probability. We also analyze the effect of varying transmission powers on the performance of the system
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