42 research outputs found
An Improved Multi-layer Cooperation Routing in Visual Sensor Network for Energy Minimization
Recent development on visual sensor networks (VSN) have shown the emergence of VSN as an important class of sensor-based distributed intelligent systems, with unique performance, complexity, and quality of service challenges. Furthermore, the popularity of VSN had attracted researchers and industries from many applications. Basically, VSN consists of a large number of low-power camera nodes, visual sensor networks support a great number of novel vision-based applications. The information provided by the camera nodes from a monitored site were collected data and processed in distributed and collaboratively. The use of multiple cameras in the network provides different views of the scene which enhances the reliability of the captured events. However, the cameras combined with the network's resource produce large amount of image data which require more energy consumption. Many research experts are working and publishing research papers on energy minimization in visual sensor network. However, there are no special attentions given by researchers on multi-layer cooperation routing in visual sensor network (VSN) particularly on the deficiency of forward-thinking innovation. This research proposed a new method that put forward the step and use (CO-VSN) multi-layer routing arrangement in visual sensor network. The performance of the proposed method is then compared with RASE protocol in different parameters and the result shows some meditation change in the stability of the network, increase the network life, reduce packet loss and energy drainage reduce in the VSNs. Even though, the RASE scheme used channel condition for movement of data and yet the proposed CO-VSN used cooperation and demonstrated better results
Practical packet combining for use with cooperative and non-cooperative ARQ schemes in wireless sensor networks
Although it is envisaged that advances in technology will follow a "Moores Law" trend for many years to come, one of the aims of Wireless Sensor Networks (WSNs) is to reduce the size of the nodes as much as possible. The issue of limited resources on current devices may therefore not improve much with future designs as a result. There is a pressing need, therefore, for simple, efficient protocols and algorithms that can maximise the use of available resources in an energy efficient manner.
In this thesis an improved packet combining scheme useful on low power, resource-constrained sensor networks is developed. The algorithm is applicable in areas where
currently only more complex combining approaches are used. These include cooperative communications and hybrid-ARQ schemes which have been shown to be of major benefit for wireless communications. Using the packet combining scheme developed in this thesis more than an 85% reduction in energy costs are possible over previous, similar approaches. Both simulated and practical experiments are developed in which the algorithm is shown to offer up to approximately 2.5 dB reduction in the required Signal-to-Noise ratio (SNR) for a particular Packet Error Rate (PER). This is a welcome result as complex schemes, such as maximal-ratio combining, are not implementable on many of the resource constrained devices under consideration.
A motivational side study on the transitional region is also carried out in this thesis. This region has been shown to be somewhat of a problem for WSNs. It is characterised
by variable packet reception rate caused by a combination of fading and manufacturing variances in the radio receivers. Experiments are carried out to determine whether
or not a spread-spectrum architecture has any effect on the size of this region, as has been suggested in previous work. It is shown that, for the particular setup tested, the
transitional region still has significant extent even when employing a spread-spectrum architecture. This result further motivates the need for the packet combining scheme
developed as it is precisely in zones such as the transitional region that packet combining will be of most benefit
Full duplex-transceivers : architectures and performance analysis
PhD ThesisThe revolution of the 5G communication systems will result in 10,000 times increase
in the total mobile broadband traffic in the 2020s, which will increase the
demand on the limited wireless spectrum. This has highlighted the need for an
efficient frequency-reuse technique that can meet the ever-increasing demand on
the available frequency resources. In-band full-duplex (FD) wireless technology
that enables the transceiver nodes to transmit and receive simultaneously over the
same frequency band, has gained tremendous attention as a promising technology
to double the spectral efficiency of the traditional half-duplex (HD) systems. However,
this technology faces a formidable challenge, that is the large power difference
between the self-interference (SI) signal and the signal of interest from a remote
transceiver node. In this thesis, we focus on the architecture of the FD transceivers
and investigate their ability to approximately double the throughput and the spectral
efficiency of the conventional HD systems. Moreover, this thesis is concerned with
the design of efficient self-interference cancellation schemes that can be combined
with the architecture of the FD transceiver nodes in order to effectively suppress the
SI signal and enable the FD mode. In particular, an orthogonal frequency-division
multiplexing (OFDM) based amplify-and-forward (AF) FD physical-layer network
coding (PLNC) system is proposed. To enable the FD mode in the proposed system,
a hybrid SIC scheme that is a combination of passive SIC mechanism and
active SIC technique is exploited at each transceiver node of that system. Next, we
propose an adaptive SIC scheme, which utilizes the normalized least-mean-square
(NLMS) algorithm to effectively suppress the SI signal to the level of the noise
floor. The proposed adaptive SIC is then utilized in a denoise-and-forward (DNF)
FD-PLNC system to enable the FD mode. Finally, we introduce a novel overthe-
air SIC scheme that can effectively mitigate the SI signal before it arrives the
local analog-to-digital converter (ADC) of the FD transceiver nodes. Furthermore,
the impact of the hardware impairments on the performance of the introduced SIC
scheme is examined and characterized.Iraq, and the Ministry of
Higher Education and Scientific Research (MOHSR
D13.2 Techniques and performance analysis on energy- and bandwidth-efficient communications and networking
Deliverable D13.2 del projecte europeu NEWCOM#The report presents the status of the research work of the
various Joint Research Activities (JRA) in WP1.3 and the results
that were developed up to the second year of the project. For
each activity there is a description, an illustration of the
adherence to and relevance with the identified fundamental
open issues, a short presentation of the main results, and a
roadmap for the future joint research. In the Annex, for each
JRA, the main technical details on specific scientific activities
are described in detail.Peer ReviewedPostprint (published version