A Switch On/Off Relaying Scheme in TDMB Cooperative System

2013 ◽  
Vol 462-463 ◽  
pp. 167-170
Author(s):  
Jin Ren
Keyword(s):  
Wireless Channels ◽  
Base Station ◽  
Digital Television ◽  
Relay Station ◽  
Cooperative System ◽  
Wireless System ◽  
Digital Multimedia ◽  
Relay Stations

Terrestrial Digital Multimedia Broadcasting (TDMB) is one popular broadcasting standard that enable digital television transmissions to hand held receivers and cooperative system take advantage of the broadcast nature of wireless channels, uses relay stations as virtual antennas. Relay stations are an attractive solution to penetrate the wireless system with lower transmitting power at the Base station. In this paper, we presented a scheme can switch on/off the power weighting ratio between Base station and Relay station in TDMB cooperative system. It will control the active relays in different channel propagations effectively.

An Efficient IR-HARQ Power Allocation for Relay-Aided Cellular Networks

2018 ◽  
Vol 27 (12) ◽  
pp. 1850195
Author(s):  
P. Mangayarkarasi ◽  
J. Raja
Keyword(s):  
Power Allocation ◽  
Cellular Networks ◽  
Channel Capacity ◽  
Energy Efficient ◽  
Base Station ◽  
Relay Station ◽  
Decode And Forward ◽  
Relay Placement ◽  
Cell Coverage ◽  
The Impact

Energy-efficient and reliable data transmission is a challenging task in wireless relay networks (WRNs). Energy efficiency in cellular networks has received significant attention because of the present need for reduced energy consumption, thereby maintaining the profitability of networks, which in turn makes these networks “greener”. The urban cell topography needs more energy to cover the total area of the cell. The base station does not cover the entire area in a given topography and adding more number of base stations is a cost prohibitive one. Energy-efficient relay placement model which calculates the maximum cell coverage is proposed in this work that covers all sectors and also an energy-efficient incremental redundancy-hybrid automatic repeat request (IR-HARQ) power allocation scheme to improve the reliability of the network by improving the overall network throughput is proposed. An IR-HARQ power allocation method maximizes the average incremental mutual information at each round, and its throughput quickly converges to the ergodic channel capacity as the number of retransmissions increases. Simulation results show that the proposed IR-HARQ power allocation achieves full channel capacity with average transmission delay and maintains good throughput under less power consumption. Also the impact of relaying performance on node distances between relay station and base station as well as between user and relay station and relay height for line of sight conditions are analyzed using full decode and forward (FDF) and partial decode and forward (PDF) relaying schemes. Compared to FDF scheme, PDF scheme provides better performance and allows more freedom in the relay placement for an increase in cell coverage.

scholarly journals Desarrollo de un sistema inalámbrico escalable de medición de humedad del suelo en un cultivo de vid

2020 ◽  
pp. 20-30
Author(s):  
Ortega-Corral César ◽  
B. Ricardo Eaton-González ◽  
Florencio López Cruz ◽  
Laura Rocío, Díaz-Santana Rocha
Keyword(s):  
Soil Moisture ◽  
Wireless Sensor Network ◽  
Sensor Network ◽  
Precision Agriculture ◽  
Drip Irrigation ◽  
Base Station ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Wireless System ◽  
Different Depths

We present a wireless system applied to precision agriculture, made up of sensor nodes that measure soil moisture at different depths, applied to vine crops where drip irrigation is applied. The intention is to prepare a system for scaling, and to create a Wireless Sensor Network (WSN) that communicates by radio frequency with a base station (ET), so that the gathered data is stored locally and can be sent out an Internet gateway.

scholarly journals Hybrid RF/visible light communication in downlink wireless system

2018 ◽  
Vol 7 (2.28) ◽  
pp. 272
Author(s):  
Tharindu D. Ponnimbaduge Perera ◽  
Akashkumar Rajaram ◽  
Sangay Chedup ◽  
Dushantha Nalin K. Jayakody ◽  
Bin Chen
Keyword(s):  
Visible Light ◽  
High Speed ◽  
Visible Light Communication ◽  
Symbol Error Rate ◽  
Electrical Signal ◽  
Cooperative System ◽  
Wireless System ◽  
Communication Models ◽  
Rf Communication ◽  
High Speed Data

The spectrum crunch in Radio Frequency (RF) Communication and the prospect of Visible Light Communication (VLC) as an alternative to RF has made way for high speed VLC deployment. The ubiquitous coverage of RF and the high speed data rate achieved with VLC, make the two technologies complimentary to each other, making the hybrid RF/VLC an emerging trend in wireless networks. This study presents a downlink communication of a hybrid RF-VLC, where the signal received through RF channel by a relay is decoded and the symbols are converted into an electrical signals. The electrical signal is fed to an array of LEDs in the relay where data is transmitted in rays of light from LEDs. The hybrid RFVLC system performance is compared with a conventional RF system to understand the performance difference between the two communication models. Thus, the performance of both system models are analysed in terms of Symbol Error Rate and Outage Probability. Numerical results show that the proposed hybrid RF-VLC system is superior to conventional lone RF cooperative system.  

scholarly journals STEERABLE TOROIDAL BIFOCAL LENS-ARRAY ANTENNA IN 57–64 GHZ RANGE

2019 ◽  
Vol 22 (3) ◽  
pp. 36-47
Author(s):  
Alexander A. Maltsev ◽  
Valentin M. Seleznev ◽  
Alexander S. Rulkov ◽  
Olesya V. Bolkhovskaya
Keyword(s):  
Low Cost ◽  
Antenna System ◽  
Base Station ◽  
Cellular Systems ◽  
Array Antenna ◽  
Lens Antenna ◽  
Lens Array ◽  
Steerable Antenna ◽  
Antenna Systems ◽  
Relay Stations

Introduction. Currently, one of the most promising approaches of the 5th generation mobile wireless systems development is the deployment of heterogeneous networks based on existing LTE cellular systems with large and small cells. The main elements of such networks can be small low cost relay stations equipped with highly directional steerable antenna systems to connect small cells with LTE base station serving macrocell. Objective. Existing solutions are either too expensive or not allowing flexible rearrangement of current information transmission lines. The objective of this work is to develop antenna equipment for low cost relay stations based on simple steerable antenna systems of millimetre wavelength (57-64 GHz), which allow beamsteering in both azimuth and elevation planes. Methods and materials. The developed steerable bifocal lens antenna system is a lens of a special shape made of a high molecular weight polyethylene and integrated with a phased array antenna. A key feature of the designed antenna system is a wide-angle beamsteering in the azimuth plane and ability to adjust the beam in the elevation plane. The calculation of the lens profiles was carried out by means of an approximation of geometrical optics in Matlab, and the main technical characteristics of the lens antenna system were obtained by direct electromagnetic modelling in CST Microwave Studio. Results. The prototype of the steerable bifocal lens-array antenna system is developed and its characteristics are studied. The following technical characteristics are achieved in the 57–64 GHz range: beamsteering in the elevation plane is ±3º, beamsteering in the azimuth plane is ±40º, and antenna gain is from 20 to 27.5 dBi for all angles. Conclusion. It was shown that the developed antenna system can be successfully used as receiving and transmission antenna equipment of small relay stations that transmit information in the frequency range of 57-64 GHz over a distance of 100-300 m.

Sign in / Sign up

Export Citation Format

Share Document