Performance Analysis and Modeling of MIMO Systems

In this paper, various channel estimation, interpolation and equalization techniques used in the analysis of MIMO configurations or formats are compared and the technique with the optimum performance determined. The channel estimation of these configurations were determined by modelling and simulating them in a wireless environment using MATLAB software. The figure of Merits used are the BER and MSE as a function of the SNR. The study revealed that MIMO is a more energy efficient technique since it achieved a good BER performance at lower transmit SNR, when compared to the MISO and SISO which requires higher SNR to achieve at same BER performance. This is as a result of the diversity and multiplexing gain experienced in the multiple antenna techniques using the STB

Comparative Analysis of Channel Estimation Techniques in SISO, MISO and MIMO Systems

The ever-growing need for high data rate, bandwidthefficiency, reliability, less complexity and less power consumptionin our communication systems is on the increase.Modern techniques have to be developed and put in place tomeet these requirements. Research has shown, that compared toconventional Single input Single output (SISO) systems, MultipleinputSingle output (MISO), and Multiple-input multiple-output(MIMO) can actually increase the data rate of a communicationsystem, without actually requiring more transmit power orbandwidth. This paper aims at the investigation of the existingchannel estimation techniques. Based on the pilot arrangement,the block type and comb type are compared, employing theLeast Square estimation (L.S) and Minimum Mean SquaredError (MMSE) estimators. Pilots occupy bandwidth, minimizingthe number of pilots used to estimate the channel, in orderto allow for more bandwidth utilization for data transmission,without compromising the accuracy of the estimates is takeninto consideration. Various channel interpolation techniques andpilot-data insertion ratio are investigated, simulated and compared,to determine the best performance technique with lesscomplexity and minimum power consumption. As performancemeasures, the Mean squared error (MSE) and Bit error rate(BER) as a function of Signal to noise power ratio (SNR) ofthe different channel estimation techniques are plotted, in orderto identify the technique with the most optimal performance.The complexity and energy efficiency of the techniques are alsoinvestigated. The system modelling and simulations are carriedout using Matlab simulation package. The MIMO gives theoptimum performance, followed by the MISO and SISO. Thisis as a result of the diversity and multiplexing gain experiencedin the multiple antenna techniques using the STBC

Use of Mobile Phones as Intelligent Sensors for Sound Input Analysis and Sleep State Detection

Sleep is not just a passive process, but rather a highly dynamic process that is terminated by waking up. Throughout the night a specific number of sleep stages that are repeatedly changing in various periods of time take place. These specific time intervals and specific sleep stages are very important for the wake up event. It is far more difficult to wake up during the deep NREM (2–4) stage of sleep because the rest of the body is still sleeping. On the other hand if we wake up during the mild (REM, NREM1) sleep stage it is a much more pleasant experience for us and for our bodies. This problem led the authors to undertake this study and develop a Windows Mobile-based device application called wakeNsmile. The wakeNsmile application records and monitors the sleep stages for specific amounts of time before a desired alarm time set by users. It uses a built-in microphone and determines the optimal time to wake the user up. Hence, if the user sets an alarm in wakeNsmile to 7:00 and wakeNsmile detects that a more appropriate time to wake up (REM stage) is at 6:50, the alarm will start at 6:50. The current availability and low price of mobile devices is yet another reason to use and develop such an application that will hopefully help someone to wakeNsmile in the morning. So far, the wakeNsmile application has been tested on four individuals introduced in the final section

Implementation of Time Reversal Technique for Energy Efficient Wireless Communication

From the past few years, the mobile industry has developed quickly, providing network coverage to more than 4 billion users. So more network infrastructure and maintenance of network is required which increases the energy cost and energy consumption.. So “Green” wireless communication is taking much effort for improving energy efficiency and to reduce environment impact. A new energy efficient Time Reversal Technique is proposed. Time reversal is a pre-filtering/focusing signal processing technique for green wireless communication. The temporal effect and spatial focusing effects reduce the interference and receiver complexity for TR wireless communication. In multi path environment it adds all the reflected signals constructively and increase the signal strength at the receiver. It require low transmit power than the direct transmission of signal. Therefore the focusing property of TR simplify receiver design. The theoretical and simulation analysis show reduction in transmit power and improved BER. In this thesis work, time reversal technique and its focusing properties are studied in detail. The temporal and spatial focusing effects of TR technique are simulated in MATLAB. TR technique is implemented for single user and multi user case. A new wireless channel access method Time Reversal Division Multiple Access also implemented for multi user downlink link system

Modeling the interrelationships among barriers to sustainable supply chain management in leather industry

© 2018 Elsevier Ltd The leather industry of Bangladesh is facing considerable amounts of pressure to adopt sustainable supply chain management (SSCM). While there are some studies that have examined barriers to SSCM practices in developed and developing countries in various domains, these are not necessarily applicable to the Bangladeshi leather industry. To bridge this gap, it is crucial to identify most influential barriers to SSCM practices, particularly in the context of developing economies. Therefore, this study identifies such barriers and examines the causal relationships between them with an aim to facilitate the effective implementation of SSCM in the Bangladeshi leather processing industry. Thirty-five barriers to SSCM implementation were identified through a detailed literature review and a survey of leather processing industry experts. Among them, the most common 20 barriers were selected with the help of industry experts. Then, a blended, grey-based Decision Making Trial and Evaluation Laboratory (DEMATEL) approach was utilized to examine their interrelationships. The results demonstrate that nine barriers could be classified as “causal” and eleven as “influenced”. ‘Lack of awareness of local customers in green products’ and ‘lack of commitment from top management’ took high priority in the causal group. ‘Lack of reverse logistics practices’ and ‘Outdated machineries’ were the most influenced barriers. This research uses a leather processing company as a case study for demonstrating the proposed model. The findings aim to support the leather processing industry in a structural way, so that industrial managers can identify the most influential barriers and work to eliminate them. This study may be useful to stakeholders to achieve sustainable development

An implementation path for green information technology systems in the Ghanaian mining industry

The mining and extractive industry’s operations have significant harmful environmental consequences. Mining companies have started adopting green supply chain management (GSCM) practices which include green information technology systems (GITS) to help provide economic benefits while seeking minimal environmental damage. These mining organizations face significant hurdles related to introducing and implementing various GSCM practices which can address some of the environmental burdens. This study addresses this issue by adopting a GSCM practices framework and applying a novel decision support method that integrates grey numbers with DEMATEL and the NK model for evaluating and developing an implementation path model. Using a multiple case field study with input from managers of the Ghanaian gold mining industry, the adopted GSCM practices framework and methodology is applied. The results provide an evaluation and development path model to guide these organizations and managers for GSCM planning and investment decisions. The path results show that these organizations should first develop SSP (Strategic Supplier Partnership) with their suppliers for implementing GITS (Green Information Technology and Systems) and other GSCM practices. These results provide some exploratory insight and guidelines for managers and policy-makers who seek to integrate green initiatives. This study also sets the stage for further investigation of organizational greening in developing countries and the mining industry

Projeto de tecnologias e sistemas de informação: estudo de caso no domínio do green computing

Dissertação de mestrado em Sistemas de InformaçãoA sustentabilidade ambiental é um problema presente em toda a sociedade e constitui um dos grandes desafios da atualidade. As Tecnologias da Informação têm neste contexto um papel de destaque, fruto das suas capacidades. A sua utilização generalizada leva a que o impacto a nível ambiental seja significativo e, como tal, cresce a importância da sua utilização de forma eficiente. As organizações têm um papel e responsabilidade centrais no que toca à sustentabilidade ambiental e deverão direcionar esforços para estratégias de sustentabilidade. Os Sistemas de Informação, como força impulsionadora da mudança e do desenvolvimento organizacional, podem ser uma ferramenta de promoção da eficiência na utilização dos recursos. O desenvolvimento das técnicas de virtualização veio permitir uma utilização mais eficiente dos recursos computacionais, impulsionando o advento do chamado Green Computing. Neste trabalho é abordado o conceito de Green Computing, analisando os aspetos organizacionais da implementação de estratégias de sustentabilidade ambiental, como a necessidade de consciencialização e de adaptação da cultura organizacional. Sendo a virtualização uma componente importante do Green Computing, será também analisado este assunto, nomeadamente em termos de modelos de virtualização de hardware, em especial no que respeita a virtual desktop. O desenvolvimento de Sistemas de Informação na perspetiva do duplo-uso será também contemplado, tendo em conta que a partilha de conhecimento possibilita o desenvolvimento de soluções com impacto generalizado na sociedade. Este trabalho visa o desenvolvimento de um estudo de aplicação dos domínios de Green Computing a nível organizacional. Assim, a principal finalidade e o respetivo contributo é a proposta de um processo para implementação organizacional de Green Computing, recorrendo à virtualização de hardware, focado na eficiência ambiental, tendo em consideração uma vertente de duplo-uso. Para o desenvolvimento do trabalho foi adotada a metodologia Design Science Research.Environmental sustainability is an emerging problem, representing one of the greatest challenges of today’s society. Among many sectors and industries, Information Technologies have also a prominent role on this subject. The widespread use of these technologies leads to a significant environmental impact, that has increasingly brought to the spotlight the importance of thinking in efficiency terms regarding technological solutions. Organizations have a central role and responsibility in environmental sustainability matters and should take the lead focusing efforts on sustainability strategies. Information Systems are a driving force on organizational change and development, naturally presenting a high potential as a tool to promote efficiency in resources management. Currently we can already see developments on virtualization techniques, enabling an increased efficiency on computing resources utilization and contributing to boost the advent of the so called Green Computing. This work concentrates on Green Computing, on the organizational aspects connected to the implementation of environmentally focused strategies, namely the necessity to raise organizational awareness and culture adaptation. Virtualization is also addressed as it is a key component on Green Computing, particularly hardware virtualization models and especially virtual desktop. Information Systems with a dual use perspective are also analyzed, as these largely contribute to knowledge sharing and therefore to enable solutions with high impact on society. The goal of this dissertation is to have a solid study on Green Computing applications on an organizational level. The main objective is the proposal of a process for organizational implementation of Green Computing principles, through hardware virtualization, focusing on the environmental efficiency and considering the particularities of the dual use. Design Science Research methodology was adopted for the development of this work

Green Networking for Major Components of Information Communication Technology Systems

<p>Abstract</p> <p>Green Networking can be the way to help reduce carbon emissions by the Information and Communications Technology (ICT) Industry. This paper presents some of the major components of Green Networking and discusses how the carbon footprint of these components can be reduced.</p

Green Networking for Major Components of Information Communication Technology Systems

Green Networking can be the way to help reduce carbon emissions by the Information and Communications Technology (ICT) Industry. This paper presents some of the major components of Green Networking and discusses how the carbon footprint of these components can be reduced

Sustainability use of information and communication technologies: a case study of an asset management company

Magister Commercii (Information Management) - MCom(IM)The problem of global warming has triggered a number of environmental initiatives aimed at mitigating climate change, many of which are driven at governmental level - although private organisations have also taken the initiative. The organisation under study - hereafter referred to as “Company-A” - is one such organisation which has taken strides in incorporating environmental initiatives in its business processes. Company-A is a South African based asset management organisation which has seen rapid growth in its business operations and consequently the number of its employees. This growth has necessitated the need for a new office building. At the commencement of this study the organisation was in the process of planning for a new office building to accommodate its growth. The senior management of Company-A recognised the importance of implementing environmentally friendly practices at the new office building, and sought the services of a sustainability consultancy firm to assist in the planning for the new office building. This study was necessitated by the fact that despite the company’s recognition of the importance and need to implement environmentally friendly processes within its business processes, there was a lack of understanding or appreciation of how ICT could be used in an environmentally friendly and sustainable manner in its new office building. With this problem in mind - the researcher - in consultation with the organisations’ new office building project manager and research supervisor, formulated a research question which was continuously refined until such a point that it was clear. It was envisaged that a research study to answer the research question: How can Information and Communication Technologies (ICTs) be used to support environmental sustainability in an organisation? - would provide insight on how the organisation’s top management could deal with the aforementioned problem. The primary purpose of the study was to assist Company-A management in making informed decisions regarding sustainability ICT use, the research can also be used as a foundation in the formulation of the organisation’s “green” ICT strategies and policies. The main research question was divided into smaller sub questions to give structure, clarity and direction in addressing the main research question. These sub questions were in turn used to formulate the research objectives which set the goals and boundaries of this study