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    Multi-carrier based cooperative cognitive network

    , Article IEEE Vehicular Technology Conference, 15 May 2011 through 18 May 2011 ; May , 2011 ; 15502252 (ISSN) ; 9781424483310 (ISBN) Golrezaei, N ; Mansourifard, P ; Nasiri Kenari, M ; Sharif University of Technology
    2011
    Abstract
    In this paper, we propose a novel cognitive cooperative relaying scheme using multi-carrier transmission in which cognitive users assist primary users by relaying their information using Decode and Forward (DF) strategy. The best cognitive user is selected as a relay for a Primary User (PU). Outage probability of the PU is investigated. Our analyses show substantial improvements in the outage probability of the PU when using the proposed cooperative scheme compared to non-cooperative one. We also perform several simulations to corroborate our theoretical results  

    Optimal planning of a multi-carrier microgrid (MCMG) considering demand-side management

    , Article International Journal of Renewable Energy Research ; Volume 8, Issue 1 , 2018 , Pages 238-249 ; 13090127 (ISSN) Amir, V ; Jadid, S ; Ehsan, M ; Sharif University of Technology
    International Journal of Renewable Energy Research  2018
    Abstract
    The multi-carrier microgrid (MCMG) is a restricted district comprising convertors and energy storage systems (ESSs) that are used to fulfill various energy demands. The structure and optimal operation of these MCMGs with regard to fulfilling multi-carrier demands are presented in relation to their rapid spread. In this paper, a two-stage optimum planning and design method for an MCMG is presented in the planning horizon. The investment and operation (fuel and maintenance) costs are considered concurrently to find the optimal type and size of components over the planning horizon. At the first stage, the genetic algorithm (GA) is applied to determine the optimal type and size of components,... 

    Centralized home energy management in multi-carrier energy frameworks

    , Article 2015 IEEE 15th International Conference on Environment and Electrical Engineering, EEEIC 2015 - Conference Proceedings, 10 June 2015 through 13 June 2015 ; 2015 , Pages 1562-1566 ; 9781479979936 (ISBN) Rastegar, M ; Fotuhi-Firuzabad, M ; Zareipour, H ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    This paper proposes a centralized optimization-based home energy management (HEM) scheme in a macro energy hub structure. An energy hub management system manages the aggregated load of a group of residential micro energy hubs to minimize the total load deviation. The operational characteristics of the household appliances and the threshold energy cost of the customers are incorporated in the propounded method to provide the customers' comfort. Numerical studies show the effectiveness of the proposed method performance  

    Probabilistic energy flow analysis of multi-carrier energy system in the presence of energy DR programs

    , Article 2019 Smart Gird Conference, SGC 2019, 18 December 2019 through 19 December 2019 ; 2019 ; 9781728158945 (ISBN) Massrur, H. R ; Fotuhi Firuzabad, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    In recent years, a great deal of attention has been paid to multi-energy systems that improve energy efficiency and reliability. In this respect, this paper examines the issue of energy flow of these systems in a probabilistic context in the presence of energy responsive programs. Responsive energy programs are provided by system operator of multi-carrier energy to manage these networks where energy customers can participate in it. The probabilistic method used is 2m + 1 point estimation method, which has high speed and high accuracy. The presented numerical results show the impact of each responsive energy program on the cost of operating a multi-carrier system. © 2019 IEEE  

    Performance evaluation of LDPC coded MC-FH-CDMA system over fading channels

    , Article 14th IEEE 2003 International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC2003, Beijing, 7 September 2003 through 10 September 2003 ; Volume 2 , 2003 , Pages 1574-1578 ; 0780378229 (ISBN); 9780780378223 (ISBN) Behroozi, H ; Haghighat, J ; Nasiri Kenari, M ; Jamali, S. H ; Sharif University of Technology
    2003
    Abstract
    In this paper, we consider the application of Low-Density Parity-Check (LDPC) codes in multi-carrier frequency-hopping (MC-FH) CDMA systems. We evaluate the performance of the coded system in a slowly Rayleigh fading frequency-selective channel using different construction methods of regular LDPC codes. We then compare the results with those of the Super-Orthogonal coded system. Our simulation results show that the LDPC coded scheme significantly outperforms the uncoded and the Super-Orthogonal coded scheme. Finally, we propose a new semi-random construction of regular LDPC code and evaluate its performance in MC-FH-CDMA system. Our numerical results indicate that this new construction... 

    Presenting a New Model for Planning Studies of a Multi-energy Microgrid to Achieve a Low-carbon Society

    , M.Sc. Thesis Sharif University of Technology Nasiri, Tohid (Author) ; Moeini Aghtaie, Moein (Supervisor)
    Abstract
    With the growing population and the development of human societies, the demand for energy increases. And it is expected that for the next few decades, fossil fuels will continue to be recognized as the main sources of energy supply and used to meet energy demand. One of the biggest disadvantages of fossil fuel consumption is the emission of greenhouse gases such as carbon dioxide, which raises the Earth's temperature and has devastating effects on the climate and the lives of its inhabitants. On the other hand, fossil fuels are recognized as non-renewable sources and their lifespan is only for the next few decades. Today, one of the major concerns of societies, especially in developed... 

    MILP model for integrated expansion planning of multi-carrier active energy systems

    , Article IET Generation, Transmission and Distribution ; Volume 13, Issue 7 , 2019 , Pages 1177-1189 ; 17518687 (ISSN) Ghasemi, H ; Aghaei, J ; Gharehpetian, G. B ; Safdarian, A ; Sharif University of Technology
    Institution of Engineering and Technology  2019
    Abstract
    In growing economic energy systems, the interdependency of various energy infrastructures has led to a change in countries' policies in their expansion planning of energy networks. In this study, a mixed-integer non-linear programming (MINLP) model is proposed for expansion planning of the multi-carrier systems including electricity and gas distribution networks. The optimal planning determines the best location, time, and alternative for network assets in order to minimise investment costs and reduce losses. Also, as another distinctive feature of this study, given the integration of electricity and gas distribution networks and the complexity of the problem, a new MILP model using... 

    Development of the energy hub networks based on distributed energy technologies

    , Article Simulation Series, 26 July 2015 through 29 July 2015 ; Volume 47, Issue 10 , 2015 , Pages 216-223 ; 07359276 (ISSN) Maroufmashat, A ; Elkamel, A ; Sattari Khavas, S ; Fowler, M ; Roshandel, R ; Elsholkami, M ; Sharif University of Technology
    The Society for Modeling and Simulation International  2015
    Abstract
    In this paper the creation of multiple energy hubs that make up a complex energy network are modeled and optimized for a selection of six scenarios to examine both their financial viability and potential reduction of greenhouse gas emissions. As a proposed case study scenario for the model, three energy hubs are considered: a 'residential complex (RC)', a 'commercial shopping plaza (CS)', and a 'school (S)'. The use of combined heat and power systems, solar photovoltaic, solar collectors and network interaction are also examined for their impact on efficiency and cost. The modeling is undertaken and carried out by General Algebraic Modeling System (GAMS). It is shown that cost can be reduced... 

    Multistage expansion co-planning of integrated natural gas and electricity distribution systems

    , Article Energies ; Volume 12, Issue 6 , 2019 ; 19961073 (ISSN) Jooshaki, M ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Lehtonen, M ; Sharif University of Technology
    MDPI AG  2019
    Abstract
    This paper focuses on expansion co-planning studies of natural gas and electricity distribution systems. The aim is to develop a mixed-integer linear programming (MILP) model for such problems to guarantee the finite convergence to optimality. To this end, at first the interconnection of electricity and natural gas networks at demand nodes is modelled by the concept of energy hub (EH). Then, mathematical model of expansion studies associated with the natural gas, electricity and EHs are extracted. The optimization models of these three expansion studies incorporate investment and operation costs. Based on these separate planning problems, which are all in the form of mixed-integer nonlinear... 

    Multistage expansion co-planning of integrated natural gas and electricity distribution systems

    , Article Energies ; Volume 12, Issue 6 , 2019 ; 19961073 (ISSN) Jooshaki, M ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Lehtonen, M ; Sharif University of Technology
    MDPI AG  2019
    Abstract
    This paper focuses on expansion co-planning studies of natural gas and electricity distribution systems. The aim is to develop a mixed-integer linear programming (MILP) model for such problems to guarantee the finite convergence to optimality. To this end, at first the interconnection of electricity and natural gas networks at demand nodes is modelled by the concept of energy hub (EH). Then, mathematical model of expansion studies associated with the natural gas, electricity and EHs are extracted. The optimization models of these three expansion studies incorporate investment and operation costs. Based on these separate planning problems, which are all in the form of mixed-integer nonlinear... 

    Optimal scheduling of multi-carrier energy system based on energy hub concept considering power-to-gas storage

    , Article IEEE Power and Energy Society Innovative Smart Grid Technologies Conference, ISGT 2020, 17 through 20 February 2020 ; 7 May , 2020 Habibifar, R ; Khoshjahan, M ; Ghasemi, M. A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2020
    Abstract
    Supplying sustainable energy is of a critical prominence nowadays. A main outcome of the galloping development in energy generation technologies is the ability to integrate multi-carrier energy systems that facilitates meeting the fast growth of energy demand. Energy hub is one of the main infrastructures making the incorporation of multi-carrier systems smoother. In this paper, the optimal scheduling problem of an energy hub structure equipped with combined heat and power, boiler, power-to-gas storage, thermal energy storage and electrical energy storage in order to supply power, heat and gas demands is presented. Power to gas is regarded as a new technology that creates a connection... 

    A decomposed solution to multiple-energy carriers optimal power flow

    , Article IEEE Transactions on Power Systems ; Vol. 29, issue. 2 , March , 2014 , p. 707-716 ; ISSN: 8858950 Moeini-Aghtaie, M ; Abbaspour, A ; Fotuhi-Firuzabad, M ; Hajipour, E ; Sharif University of Technology
    Abstract
    Presence of energy hubs in the future vision of energy networks creates a great opportunity for system planners and operators to move towards more efficient systems. The role of energy hubs as the intermediate in multi-carrier energy (MCE) systems calls for a generic framework to study the new upcoming technical as well as economical effects on the system performance. In response, this paper attempts to develop a general optimization and modeling framework for coupled power flow studies on different energy infrastructures. This, as a large-scale nonlinear problem, is approached through a robust optimization technique, i.e., multi-agent genetic algorithm (MAGA). The proposed procedure... 

    Optimal charge scheduling of PHEV in a multi-carrier energy home

    , Article 2014 14th International Conference on Environment and Electrical Engineering, EEEIC 2014 - Conference Proceedings ; 2014 , p. 199-203 ; ISBN: 9781480000000 Rastegar, M ; Fotuhi-Firuzabad, M ; Sharif University of Technology
    Abstract
    The presence of different energy carriers as well as the advent of new multi-generation technologies such as combined heat and power (CHP) at homes necessitates designing an integrated model for optimal operation of such multi-carrier energy home. A residential energy hub model including a CHP and a Plug-in hybrid electric vehicle (PHEV) is presented in this paper to show the multi-carrier energy system operation. In addition, this paper proposes an optimization-based formulation for PHEV charging control in the residential energy hub. The payment cost is minimized for the charge scheduling of PHEV through optimization of the residential energy hub operation in response to the... 

    Resource allocation using fragmented-spectrum synchronous OFDM-CDMA in cognitive radio networks

    , Article IWCIT 2014 - Iran Workshop on Communication and Information Theory ; May , 2014 ; ISBN: 9781479948772 Akhoondi, F ; Poursaeed, O ; Salehi, J. A ; Sharif University of Technology
    Abstract
    This paper presents a fragmented-spectrum synchronous OFDM-CDMA modulation and utilize it as secondary users modulation in a cognitive radio-based network to provide high data rate by efficiently exploiting available spectrum bands in a target spectral range while simultaneously offering multiple-access capability. In particular, given preexisting communications in the spectrum where the system is operating, a channel sensing and estimation method is used to obtain information of subcarrier availability. Given this information, some three-level codes are provided for emerging new cognitive radio users. Furthermore, analytical results of the system performance in a typical cognitive radio... 

    Probabilistic optimal power dispatch in multi-carrier networked microgrids under uncertainties

    , Article Energies ; Volume 10, Issue 11 , 2017 ; 19961073 (ISSN) Amir, V ; Jadid, S ; Ehsan, M ; Sharif University of Technology
    Abstract
    A microgrid (MG) is a small-scale version of the power system which makes possible the integration of renewable resources as well as achieving maximum demand side management (DSM) utilization. The future power system will be faced with severe uncertainties owing to penetration of renewable resources. Consequently, the uncertainty assessment of system performance is essential. The conventional energy scheduling in an MG may not be suitable for active distribution networks. Hence, this study focuses on the probabilistic analysis of optimal power dispatch considering economic aspects in a multi-carrier networked microgrid. The aim is to study the impact of uncertain behavior of loads, renewable... 

    Performance evaluations and comparisons of several LDPC coded MC-FH-CDMA systems

    , Article Scientia Iranica ; Volume 13, Issue 4 , 2006 , Pages 337-347 ; 10263098 (ISSN) Behroozi, H ; Haghighat, J ; Nasiri Kenari, M ; Jamali, S. H ; Sharif University of Technology
    Sharif University of Technology  2006
    Abstract
    In this paper, the application of regular Low-Density Parity-Check (LDPC) codes in Multi-Carrier Frequency-Hopping (MC-FH) CDMA systems is studied. To this end, different well-known constructions of regular LDPC codes are considered and the performance of LDPC coded MC-FH-CDMA systems, based on these constructions, are evaluated and compared in a frequency-selective slowly Rayleigh fading channel. These results are compared with those previously reported for super-orthogonal convolutionally coded MC-FH-CDMA systems. The simulation results indicate that the LDPC coded MC-FH-CDMA system significantly outperforms the uncoded and super-orthogonal convolutionally coded schemes. To alleviate the... 

    Design concepts and performance analysis of multicarrier CDMA for indoor visible light communications

    , Article Journal of Optical Communications and Networking ; Volume 7, Issue 6 , 2015 , Pages 554-562 ; 19430620 (ISSN) Shoreh, M. H ; Fallahpour, A ; Salehi, J. A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    In this paper, we present a design methodology with implementational insight and evaluate the performance of a multicarrier code-division multiple access (MC-CDMA) system using intensity modulation/direct detection scheme suitable for an indoor visible light communication (VLC) environment. The proposed system is a CDMA system based on an orthogonal frequency division multiplexing (OFDM) platform. To overcome the light-dimming issue, we use a newly proposed methodology, namely, polarity reversed optical OFDM (PRO-OFDM). A unipolar signal is either added to the minimum current or subtracted from the maximum current in the LED linear current range to provide various amounts of dimming. The... 

    Cognitive-engined spectrum-fragmented synchronous MC-CDMA based on generalized hadamard codes

    , Article 2015 IEEE Wireless Communications and Networking Conference Workshops, WCNCW 2015, 9 March 2015 through 12 March 2015 ; March , 2015 , Pages 159-163 ; 9781479987603 (ISBN) Shoreh, M. H ; Khojasteh, M. J ; Poursaeed, O ; Salehi, J. A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    In Cognitive Radio (CR), in order to avoid interference in the Primary Users (PU), some subcarriers need to be deactivated. In systems based on Multicarrier Code Division Multiple Access (MC-CDMA), this causes losing orthogonality among different spreading codes, leading to poor Bit Error Rate (BER) performance. The performance of such system can be improved by using Generalized Hadamard Codes (GHC) instead of conventional Hadamard codes which avoids the loss of orthogonality. This is due to the fact that unlike conventional Hadamard codes, GHC are conjectured to exist for any arbitrary length. In this paper, we propose using a novel spreading code, namely, GHC for synchronous MC-CDMA in CR... 

    Applying reinforcement learning method to optimize an Energy Hub operation in the smart grid

    , Article IEEE Power and Energy Society Innovative Smart Grid Technologies Conference, ISGT 2015, 18 February through 20 February 2015 ; 2015 ; 9781479917853 (ISBN) Rayati, M ; Sheikhi, A ; Ranjbar, A. M ; Sharif University of Technology
    Abstract
    New days, the concepts of 'Smart Grid' and 'Energy Hub' have been introduced to improve the operation of the energy systems. This paper introduces a new conception entitling Smart Energy Hub (S. E. Hub), as a multi-carrier energy system in a smart grid environment. To show the application of this novel idea, we present a residential S. E. Hub which employs Reinforcement Learning (RL) method for finding a near optimal solution. The simulation results show that by applying the S. E. Hub model and then using the proposed method for a residential customer, running cost is reduced substantially. While, comparing with the classical ones, the RL method does not require any data about the... 

    Error performance analysis for generalized orthogonal frequency division multiplexing

    , Article Computers and Electrical Engineering ; Volume 61 , 2017 , Pages 139-150 ; 00457906 (ISSN) Abbaszadeh, M. H ; Khalaj, B. H ; Haghbin, A ; Sharif University of Technology
    Abstract
    Generalized Frequency Division Multiplexing (GFDM) is a cyclic filtered multicarrier modulation that may be employed for many new wireless applications. However, due to its non-orthogonal structure, a trade-off between the complexity and error performance should be considered in the design of GFDM receivers. This study proposes an orthogonal cyclic filtered multicarrier modulation called Generalized Orthogonal Frequency Division Multiplexing (GOFDM), which is based on the cyclic Perfect Reconstruction-Quadrature Mirror Filter (PR-QMF) bank. We first derive the frequency domain matrix descriptions for GOFDM linear receivers based on which, the impact of PR-QMF bank on the GOFDM error...