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    Comprehensive partial decoding approach for two-level relay networks

    , Article IET Communications ; Volume 3, Issue 4 , 2009 , Pages 585-596 ; 17518628 (ISSN) Ghabeli, L ; Aref, M. R ; Sharif University of Technology
    2009
    Abstract
    Partial decoding scheme is a scheme in which each relay decodes only part of the transmitted message. Obviously, the achievable rates proposed by the partial decoding scheme subsume the achievable rates proposed by the full decoding scheme. The other motivation of using partial decoding scheme is that there are some special classes of relay networks such as semi-deterministic and orthogonal relay networks such that their capacities are obtained via this scheme. The authors propose a comprehensive partial decoding scheme based on regular encoding/sliding window decoding analysis to propose a new achievable rate for two-level relay networks. In contrast with the previously proposed methods,... 

    Symmetric semideterministic relay networks with no interference at the relays

    , Article IEEE Transactions on Information Theory ; Volume 57, Issue 9 , 2011 , Pages 5673-5681 ; 00189448 (ISSN) Ghabeli, L ; Aref, M. R ; Sharif University of Technology
    2011
    Abstract
    A symmetric semideterministic relay network is introduced, generalizing Aref networks. In the considered model, there is no interference at the relays, but the links from the source and the relays to the sink are interfering and nondeterministic. An achievable rate is determined for an arbitrary number of relays, based on symmetric relaying and simultaneous partial and backward decoding at the sink. The information expressions of the achievable rate match those of the standard cut-set bound, but the set of probability distributions is substantially different. We also study a wireless example of the defined network where nondeterministic links are replaced with fading AWGN channels, and... 

    On achievable rates for relay networks based on partial decode-and-forward

    , Article IEEE International Symposium on Information Theory - Proceedings, 13 June 2010 through 18 June 2010, Austin, TX ; 2010 , Pages 659-663 ; 21578103 (ISSN) ; 9781424469604 (ISBN) Ghabeli, L ; Aref, M. R ; Sharif University of Technology
    2010
    Abstract
    In this paper, we investigate the performance of two strategies: simultaneous sliding window decoding (SimSlide) and simultaneous backward decoding (SimBack) when generalizing partial decode-and-forward to the relay networks. We show that these two methods yield the same achievable rates for relay networks but in comparison with sequential decoding, they yield higher rates. This is due to the fact that simultaneously decoding the different parts of the source message yields fewer bounds and this ultimately results a comprehensive and higher rate. We also introduce a special class of semi-deterministic relay networks and obtain its capacity by the proposed achievable rate  

    An achievable rate region for a class of broadcast-relay networks

    , Article IEEE Information Theory Workshop 2010, ITW 2010, 6 January 2010 through 8 January 2010, Cairo ; 2010 ; 9781424463725 (ISBN) Salehkalaibar, S ; Ghabeli, L ; Aref, M ; Sharif University of Technology
    2010
    Abstract
    In this paper we define Broadcast Relay Networks (BRN) with two relays. There are a transmitter, two relays and two receivers in the network. We find an achievable rate region for it by considering full cooperation between relays. We use symmetric relaying method at relays and Marton's broadcast code construction for the transmitter.We will show that Kramer's rate region for Broadcast Relay Channel (BRC), Ghabeli's rate for symmetric two-relay network, and Marton's rate region for Broadcast Channel are special cases of our achievable rate region  

    An achievable rate region for broadcast-relay networks with partial cooperation between relays

    , Article 2010 Australian Communications Theory Workshop, AusCTW 2010, Canberra, ACT, 3 February 2010 through 5 February 2010 ; 2010 , Pages 7-12 ; 9781424454334 (ISBN) Salehkalaibar, S ; Ghabeli, L ; Aref, M.R ; ANU - The Australian National University; ACoRN - ARC Communications Research Network; NICTA; UniSA; CSIRO ; Sharif University of Technology
    2010
    Abstract
    In this paper, we consider a different strategy for Broadcast-Relay- Networks (BRN) with two relays. There are a transmitter, two relays and two receivers in this network. The message of the transmitter intended to the receivers, has both common and private parts. The relays partially cooperate with each other and with the transmitter to send the common part of the message. The private parts of the message are sent to the corresponding receiver by the cooperation of the corresponding relay. We propose an achievable rate region for this network. In the proof, we take advantage of regular encoding/sliding window decoding at relays and simultaneous backward decoding analysis at receivers. The... 

    The asymmetric Gaussian parallel relay network

    , Article 2010 Australian Communications Theory Workshop, AusCTW 2010, Canberra, ACT, 3 February 2010 through 5 February 2010 ; 2010 , Pages 77-80 ; 9781424454334 (ISBN) Ghabeli, L ; Aref, M.R ; ANU - The Australian National University; ACoRN - ARC Communications Research Network; NICTA; UniSA; CSIRO ; Sharif University of Technology
    2010
    Abstract
    In this paper we consider the real, discrete time asymmetric Gaussian parallel relay network, the more realistic model than the symmetric one considered by Schein-Gallagar. We present achievable rates for this network that are superior rates to the Schein-Gallagar rates. The proposed methods are based on the superimposition technique used for the degraded broadcast channel and also cooperation of the relays to send as much as possible information to the receiver at the multiple access side  

    Symmetrie relaying based on partial decoding and the capacity of a class of relay networks

    , Article IET Communications ; Volume 3, Issue 1 , 2009 , Pages 151-159 ; 17518628 (ISSN) Ghabeli, L ; Aref, M. R ; Sharif University of Technology
    2009
    Abstract
    Symmetric relaying is a method of relaying in which the relays can decode the message of other relays in the network in addition to the source message. In this paper an achievable rate is presented for a symmetric two-relay network based on partial decoding. The strategy make use of familiar techniques such as product binning, regular encoding/sliding window decoding and regular encoding/backward decoding. The proposed rate is shown to subsume the previously proposed rate for feed-forward relay network based on decode-and-forward. This rate is also used to establish the capacity of a generalisation of Aref network called 'semi-deterministic relay network with no interference at the relays'... 

    A new achievable rate and the capacity of a class of semi-deterministic relay networks

    , Article 2007 IEEE International Symposium on Information Theory, ISIT 2007, Nice, 24 June 2007 through 29 June 2007 ; 2007 , Pages 281-285 ; 21578101 (ISSN) ; 1424414296 (ISBN); 9781424414291 (ISBN) Ghabeli, L ; Aref, M. R ; Sharif University of Technology
    2007
    Abstract
    In this paper, we propose an information-theoretic constructive scheme based on generalized block Markov encoding strategy for obtaining an achievable rate for multirelay networks. The coding scheme is based on partial decoding scheme where the relay decodes only part of the transmitted message. The proposed achievable rate is then used to establish the capacity of a class of semi-deterministic relay networks composed of semi-deterministic relay channels. It is shown that the proposed rate will include those of previously proposed rates based on decode-and-forward strategy in some special cases. ©2007 IEEE  

    On the reliable transmission of correlated sources over two-relay network

    , Article 2013 IEEE Information Theory Workshop, ITW 2013 ; 2013 ; 9781479913237 (ISBN) Nasiraee, M ; Akhbari, B ; Ahmadian-Attari, M ; Aref, M. R ; Sharif University of Technology
    2013
    Abstract
    In this paper, we investigate reliable transmission of three correlated discrete memoryless sources over a two-relay network. In our considered model, one of the sources is available at the sender whereas, the other two sources are known to the first and the second relay. We present both joint and separate source-channel coding schemes, and derive the corresponding sets of sufficient conditions for reliable sources transmission. The manner of cooperation in both schemes is Decode-and-Forward strategy. In the joint approach, we generalize the correlation preserving mapping technique to our model using nested backward decoding. Our proposed separate approach is based on Slepian-Wolf source... 

    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  

    Achievable rate regions for many-to-one Gaussian interference channel with a fusion centre

    , Article IET Communications ; Volume 9, Issue 6 , April , 2015 , Pages 880-887 ; 17518628 (ISSN) Baianifar, M ; Behroozi, H
    Institution of Engineering and Technology  2015
    Abstract
    This paper considers a many-to-one Gaussian interference channel with a fusion centre (FC) where there is a K -user interference channel in which only one relay (receiver) faces interference while the remaining K-1 receivers are interference free. All the relays communicate information about their observed sequence to the FC through noiseless links at communication rate R0. First, by analysing traditional relaying schemes, i.e., Decode and Forward, Compress and Forward and Compute and Forward, three rate-regions for this setting are derived. Then, based on nested lattice codes, a new achievable rate-region is provided. Based on the proposed scheme, one can design a transmission scheme that... 

    Capacity of a class of symmetric relay networks with orthogonal components

    , Article IET Communications ; Volume 4, Issue 18 , 2010 , Pages 2181-2186 ; 17518628 (ISSN) Ghabeli, L ; Aref, M. R ; Sharif University of Technology
    2010
    Abstract
    In this study, the authors extend the concept of relay channel with orthogonal components to define a class of symmetric relay networks with orthogonal components named symmetric orthogonal relay network. In the defined network, the channels diverge from each node sender use different frequency bands whereas the channels converge to each node receiver use the same frequency band. This structure is very well understood in half-duplex transmission systems where the relays cannot send and receive at the same time or over the same frequency band. The authors show that the unicast capacity of the defined network is equal to the cut-set bound. In the achievability proof, the authors take advantage... 

    The capacity of a class of linear deterministic relay networks

    , Article ISITA/ISSSTA 2010 - 2010 International Symposium on Information Theory and Its Applications, 17 October 2010 through 20 October 2010, Taichung ; 2010 , Pages 720-725 ; 9781424460175 (ISBN) Tabatabaei Yazdi, S. M. H ; Aref, M. R ; Sharif University of Technology
    2010
    Abstract
    In this paper, we investigate optimal coding strategies for a class of linear deterministic relay networks. The network under study is a relay network, with one source, one destination, and two relay nodes. Additionally, there is a disturbing source of signals that causes interference with the information signals received by the relay nodes. Our model captures the effect of the interference of message signals and disturbing signals on a single relay network, or the interference of signals from multiple relay networks with each other in the linear deterministic framework. For several ranges of the network parameters we find upper bounds on the maximum achievable source-destination rate in the... 

    Cooperative diversity of distributed network beamforming under long-term power constraints

    , Article Proceedings - IEEE Symposium on Computers and Communications, 22 June 2010 through 25 June 2010 ; June , 2010 , Pages 268-271 ; 15301346 (ISSN) ; 9781424477555 (ISBN) Safavi, E ; Hossein Khalaj, B ; Sharif University of Technology
    Abstract
    In this paper, we analyze the cooperative diversity of amplify-and-forward half-duplex relay networks under longterm power constraints. The system model we consider consists of one transmit-receive pair and an arbitrary number of relays. This paper analyzes bit error rate and network diversity for two different power distribution scenarios in network. Using the derived network error probability, the distributed signal to noise ratio for network is introduced  

    An achievable rate for relay networks based on compress-and-forward strategy

    , Article IEEE Communications Letters ; Volume 14, Issue 4 , 2010 , Pages 279-281 ; 10897798 (ISSN) Salehkalaibar, S ; Ghabeli, L ; Aref, M. R ; Sharif University of Technology
    Abstract
    Compress-and-Forward (CF) is a well-known coding strategy proposed for relay channels. Few works which were done about the generalization of the CF strategy to the relay networks, are based on irregular encoding/successive decoding. In this paper, a new generalization of the CF strategy to the relay networks based on regular encoding/backward decoding is presented. In general, backward decoding has been shown to yield higher rates in comparison with successive decoding. Here we will investigate the performance of backward decoding in our problem and show that our achievable rate includes the previously proposed rates  

    Analysis of oscillations in relay feedback systems with fractional-order integrating plants

    , Article Journal of Computational and Nonlinear Dynamics ; Volume 12, Issue 5 , 2017 ; 15551415 (ISSN) Rezaei, D ; Tavazoei, M. S ; Sharif University of Technology
    Abstract
    Oscillatory behavior and transfer properties of relay feedback systems with a linear plant including a fractional-order integrator are studied in this paper. An expression for system response in the time domain is obtained by means of short memory principle, Poincare return map, and Mittag-Leffler functions. On the basis of this expression, the frequency of self-excited oscillations is approximated. In addition, the locus of perturbed relay system (LPRS) is derived to analyze the input-output properties of the relay system. The presented analysis is supported by a numerical example. Copyright © 2017 by ASME  

    Simultaneous partial and backward decoding approach for two-level relay networks

    , Article 2009 IEEE International Symposium on Information Theory, ISIT 2009, Seoul, 28 June 2009 through 3 July 2009 ; 2009 , Pages 517-521 ; 21578102 (ISSN); 9781424443130 (ISBN) Ghabeli, L ; Aref, M. R ; Sharif University of Technology
    2009
    Abstract
    In this paper, we propose a new achievable rate for two-level relay networks by introducing a new strategy named simultaneous partial and backward decoding. In the proposed method, benefitting from regular encoding/backward decoding strategy, different message parts transmitted in the network are simultaneously decoded at the relays and the receiver. The proposed strategy is shown to achieve better rates than the previously proposed methods based on decode-and-forward and partial decode-and-forward. © 2009 IEEE  

    A new achievable rate for relay networks based on parallel relaying

    , Article 2008 IEEE International Symposium on Information Theory, ISIT 2008, Toronto, ON, 6 July 2008 through 11 July 2008 ; 2008 , Pages 1328-1332 ; 21578101 (ISSN) ; 9781424422579 (ISBN) Ghabeli, L ; Aref, M. R ; Sharif University of Technology
    2008
    Abstract
    In this paper, we propose a new concept of relaying named parallel relaying to obtain a new achievable rate for relay networks. The proposed encoding scheme is based on partial decoding, where the relay decodes only part of the transmitted message. The superiority of our proposed method to the previous ones is that, it can be applied to the relay networks with general structure, not necessarily with feed-forward structure. The proposed achievable rate is also used to establish the capacity of a class of semi-deterministic relay network which is a generalization of Aref network. © 2008 IEEE  

    Delay and throughput analysis of a two-way opportunistic network coding-based relay network

    , Article IEEE Transactions on Wireless Communications ; Vol. 13, issue. 5 , 2014 , p. 2863-2873 Amerimehr, M. H ; Ashtiani, F ; Sharif University of Technology
    Abstract
    This paper presents an analytical study of average delay and throughput in a two-way relay network exploiting network coding to exchange source packets, where arrival and departure of packets are stochastic. In this case, a fundamental problem for the relay node is whether to wait in order to obtain a coding opportunity, leading to reduction of the number of transmissions, or sending a packet (coded/uncoded) whenever it has a transmission opportunity, leading to reduction of the packet delay. In order to address the fundamental trade-off between packet delay and transmission power, we develop three network coding schemes based on power-delay constraint of the application. We devise a... 

    Precoding in relay networks with frequency selective channels

    , Article Conference Record - Asilomar Conference on Signals, Systems and Computers ; 2012 , Pages 537-541 ; 10586393 (ISSN) ; 9781467350518 (ISBN) Schad, A ; Khalaj, B ; Pesavento, M ; Sharif University of Technology
    Abstract
    We consider a wireless network with one source, multiple relays and multiple destinations. The source and the relays are assumed to utilize multiple antennas. To reduce the effects of the frequency selective source-to-relay and relay-to-destination channels, and to compensate for the different delays of the various signal paths in the network and for multi-user interference and noise, the source, the relays and the destinations apply linear filtering to their signals. The proposed scheme generalizes the recently proposed filter-and-forward relaying scheme. We propose an iterative algorithm to solve the problem of maximizing the quality-of-service at the destinations. Simulation results...