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  • 1.
    Andersson, Mattias
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Zaidi, Syed Ali Abbas
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Wernersson, Niklas
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Nonlinear distributed sensing for closed-loop control over Gaussian channels2011In: Communication Technologies Workshop (Swe-CTW), 2011 IEEE Swedish, IEEE conference proceedings, 2011, p. 19-23Conference paper (Refereed)
    Abstract [en]

    A scenario of distributed sensing for networked control systems is considered and a new approach to distributed sensing and transmission is presented. The state process of a scalar first order linear time invariant dynamical system is sensed by a network of wireless sensors, which then instantaneously transmit their measurements to a remotely situated control unit over parallel Gaussian channels. The control unit aims to stabilize the system in mean square sense. The proposed non-linear delay-free sensing and transmission strategy is compared with the well-known amplify-and-forward strategy, using the LQG control cost as a figure of merit. It is demonstrated that the proposed nonlinear scheme outperforms the best linear scheme even when there are only two sensors in the network. The proposed sensing and transmission scheme can be implemented with a reasonable complexity and it is shown to be robust to the uncertainties in the knowledge of the sensors about the statistics of the measurement noise and the channel noise.

  • 2.
    Bilal, Ibrahim
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Zaidi, Ali A.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory.
    An Optimized Linear Scheme for Stabilization Over Multi-User Gaussian Networks2013In: 2013 Information Theory And Applications Workshop (ITA), New York: IEEE , 2013, p. 290-297Conference paper (Refereed)
    Abstract [en]

    Remote stabilization of linear dynamical systems over Gaussian networks is studied. Two linear time invariant systems (plants) with arbitrary distributed initial states are monitored by two separate sensors. The sensors communicate their measurements to two remotely situated controllers over a Gaussian interference, possibly with the assistance from a relay node. The common goal of the sensors, relay, and controllers is to stabilize the plants in mean-square sense. An optimized linear delay-free sensing and control scheme is proposed and sufficient conditions for mean-square stability are derived. These conditions reveal the relationship between plants' stability and communication channel parameters. It is shown that the proposed linear scheme can significantly outperform the existing estimation based control scheme in multi-user Gaussian networks.

  • 3.
    Bilal, Ibrahim
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Zaidi, Ali Abbas
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Feedback stabilization over a Gaussian interference relay channel2013In: 2013 IEEE 14th Workshop on Signal Processing Advances in Wireless Communications, SPAWC, IEEE , 2013, p. 560-564Conference paper (Refereed)
    Abstract [en]

    A transmission scheme for mean square stabilization of two linear systems over a Gaussian interference relay channel is studied. A delay-free linear sensing and control strategy is proposed and an achievable stability region is derived. It shows that the stability region can be significantly enlarged by deploying a relay node in such a multi-user Gaussian channels. Furthermore we observe that the separation structure between estimation and control is inadequate in high interference regime.

  • 4.
    Bilal, Ibrahim
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Zaidi, Ali Abbas
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Managing interference for stabilization over wireless channels2012In: Intelligent Control (ISIC), 2012 IEEE International Symposium on, IEEE , 2012, p. 933-938Conference paper (Refereed)
    Abstract [en]

    The remote stabilization of a first order linear plant over a wireless channel is studied. The plant is assumed to have an arbitrary distributed initial state and the wireless channel between the plant's sensor and the controller is modeled as a white Gaussian channel subject to an external interference signal. In order to combat the interference a dedicated sensor (relay) node is deployed adjacent to the interferer, which relays the interference information to both the plant's sensor and the controller. The sensor and the controller utilize this information to mitigate interference. We use delay-free linear sensing and control scheme in order to derive sufficient conditions for mean square stability. The achievable stability region significantly enlarges with the relay assisted interference cancelation scheme. Moreover the effect of interference can be completely eliminated if the encoder knows all the future values of the interference.

  • 5.
    Farhadi, Hamed
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Zaidi, Ali
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Fischione, Carlo
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Wang, Chao
    School of Electronics and Information Engineering, Tongji University, Shanghai, China.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Distributed Interference Alignment and Power Control for Wireless MIMO Interference Networks with Noisy Channel State Information2013In: 2013 First International Black Sea Conference on Communications and Networking (BlackSeaCom), IEEE conference proceedings, 2013, p. 23-27Conference paper (Refereed)
    Abstract [en]

    This paper considers a multi-input multi-output(MIMO) interference network in which each transmitter intendsto communicate with its dedicated receiver at a certain fixed rate. It is known that when perfect CSI is available at each terminal, the interference alignment technique can be applied to align theinterference signals at each receivers in a subspace independent of the desired signal subspace. The impact of interference canhence be eliminated. In practice, however, terminals in general can acquire only noisy CSI. Interference alignment cannot be perfectly performed to avoid interference leakage in the signal subspace. Thus, the quality of each communication link dependson the transmission power of the unintended transmitters. Tosolve this problem, we propose an iterative algorithm to performstochastic power control and transceiver design based on onlynoisy local CSI. The transceiver design is conducted based on the interference alignment concept, and the power control seeks solutions of efficiently assigning transmit powers to provide successful communications for all transmitter-receiver pairs.

  • 6.
    Nasiri Khormuji, Majid
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Zaidi, Ali A.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Interference Management Using Nonlinear Relaying2010In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 58, no 7, p. 1924-1930Article in journal (Refereed)
    Abstract [en]

    We consider the three-node Gaussian relay channel where the relay observes a noisy version of the interference present in the source-destination link. We investigate three fundamental relaying approaches: linear relaying, memoryless nonlinear relaying, and compress-and-forward (CF). For interference-limited cases, we illustrate that optimized memoryless nonlinear relaying almost achieves the capacity.

  • 7.
    Zaidi, Ali A.
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Khormuji, Majid Nasiri
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Nonlinear transmission strategies for a general half-duplex AWGN relay channel2011In: 2011 IEEE Swedish Communication Technologies Workshop, Swe-CTW 2011, 2011, p. 58-61Conference paper (Refereed)
    Abstract [en]

    We consider the general AWGN relay channel consisting of a source node, a half-duplex relay node and a destination node. We propose a low-complex and memoryless nonlinear transmission scheme for delay sensitive applications. The proposed nonlinear strategy provides higher achievable transmission rates than those achieved by the existing linear strategy.

  • 8.
    Zaidi, Ali A.
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Oechtering, Tobias J.
    Skoglund, Mikael
    Closed-Loop Stabilization Over Gaussian Interference Channel2011In: Proceedings of the 18th IFAC World Congress, 2011,  Volume 18, Part 1, IFAC , 2011, p. 14429-14434Conference paper (Refereed)
    Abstract [en]

    The problem of closed-loop stabilization of two scalar linear time invariant systems over symmetric white Gaussian interference channel with correlated noise components and arbitrarily distributed initial states is addressed. We propose to use linear and memoryless communication and control scheme based on the coding schemes introduced for interference networks which are an extension of the Schalkwijk-Kailath coding scheme. By employing the proposed communication and control scheme over the Gaussian interference channel, we derive sufficient conditions for mean square stability of the two linearly controlled LTI systems.

  • 9.
    Zaidi, Ali A.
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Rate sufficient conditions for closed-loop control over AWGN relay channels2010In: 2010 8th IEEE International Conference on Control and Automation, ICCA 2010, 2010, p. 602-607Conference paper (Refereed)
    Abstract [en]

    The problem of remotely controlling an unstable noiseless linear time invariant system with Gaussian distributed initial state over two different noisy relay channels with average power constraints is considered. For information transmission over orthogonal half-duplex and non-orthogonal full-duplex relay channel, we propose a coding/decoding scheme based on Schalkwijk-Kailath scheme. Therefore, we derive conditions on rate which are sufficient for mean square stability of the linearly controlled LTI system over the given relay channels.

  • 10.
    Zaidi, Ali A.
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Sufficient Conditions for Closed-Loop Control Over Multiple-Access and Broadcast Channels2010In: 49TH IEEE CONFERENCE ON DECISION AND CONTROL (CDC), 2010, p. 4771-4776Conference paper (Refereed)
    Abstract [en]

    The problem of closed-loop stabilization of two scalar linear time invariant systems over noisy multiple-access and broadcast communication channels with arbitrarily distributed initial states is addressed. We propose to use communication and control schemes based on the coding schemes introduced by Ozarow et al. for the multiple-access and the broadcast channels with noiseless feedback which are extensions of the Schalkwijk-Kailath coding scheme. By employing the proposed communication and control schemes over the multiple-access and the broadcast channels, we derive stability regions those are sufficient for mean square stability of the two linearly controlled LTI systems.

  • 11.
    Zaidi, Ali A.
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Yueksel, Serdar
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Sufficient conditions for closed-loop control over a Gaussian relay channel2011In: 2011 AMERICAN CONTROL CONFERENCE, 2011, p. 2240-2245Conference paper (Refereed)
    Abstract [en]

    The problem of remotely stabilizing a noisy first order linear time invariant system with an arbitrary distributed initial state over a general half-duplex white Gaussian relay channel is addressed. We propose to use linear and memoryless communication and control strategies which are based on the Schalkwijk-Kailath coding scheme. By employing the proposed scheme over the general half-duplex Gaussian relay channel, we derive sufficient conditions for mean square stability of the noisy first order linear time invariant dynamical system.

  • 12.
    Zaidi, Ali A.
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Yueksel, Serdar
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    On Optimal Policies for Control and Estimation Over a Gaussian Relay Channel2011In: 2011 Conference on Decision and Control, 2011, p. 5720-5725Conference paper (Refereed)
    Abstract [en]

    The problem of causal transmission of a memoryless Gaussian source over a two-hop memoryless Gaussianrelay channel is considered. The source and the relay encodershave average transmit power constraints, and the performancecriterion is mean squared distortion. The main contributionof this paper is to show that unlike in the case of a point-topoint channel, linear encoding schemes are not optimal over atwo-hop relay channel in general, extending the sub-optimalityresults which are known for more than two hops. In some cases,simple three level quantization policies employed at the sourceand at the relay can outperform the best linear policies. Furthera lower bound on the distortion is derived and it is shown thatthe distortion bounds derived using cut-set arguments are nottight in general for sensor networks.

  • 13.
    Zaidi, Ali A.
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Yueksel, Serdar
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    On optimal policies for control and estimation over a Gaussian relay channel2013In: Automatica, ISSN 0005-1098, E-ISSN 1873-2836, Vol. 49, no 9, p. 2892-2897Article in journal (Refereed)
    Abstract [en]

    The problem of causal transmission of a memoryless Gaussian source over a two-hop memoryless Gaussian relay channel is considered. The source and the relay encoders have average transmit power constraints, and the performance criterion is mean-squared distortion. The main contribution of this paper is to show that unlike the case of a point-to-point scalar Gaussian channel, linear encoding schemes are not optimal over a two-hop relay channel in general, extending the sub-optimality results which are known for more than three hops. In some cases, simple three-level quantization policies employed at the source and at the relay can outperform the best linear policies. Further a lower bound on the distortion is derived and it is shown that the distortion bounds derived using cut-set arguments are not tight in general for sensor networks.

  • 14.
    Zaidi, Ali Abbas
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Sensing and Control of Dynamical Systems Over Networks2013Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Rapid advances in sensing, computing, and wireless technologies have led to significant interest in the understanding and development of wireless networked control systems. Networked control systems consist of spatially distributed agents such as plants (dynamical systems), sensors, and controllers, that interact to achieve desired objectives. The sensors monitor the plants and communicate measurements to remotely situated controllers. The controllers apply actions to stabilize and control the plants.  Such systems have diverse applications in security, surveillance, industrial production, health monitoring, remote surgery, environment management, space missions, and intelligent transport systems. The objective of the thesis is to understand the fundamental limits and principles involved in the design of sensing and control strategies for dynamical systems controlled over communication networks.

    The thesis has three parts. Part I and Part III consider the design of sensing and control strategies for mean-square stabilization of linear dynamical systems over fundamental communication channels such as point-to-point, relay, multiple-access, broadcast, and interference channels. The sensors and other nodes within the communication network are assumed to have average power transmit constraints. Moreover, the communication links between all agents (plants, sensors, controllers) are modeled as Gaussian channels. Necessary as well as sufficient conditions for mean-square stabilization over various network topologies are derived. The necessary conditions are arrived at using information theoretic arguments such as properties of mutual information, directed information, and differential entropy. The sufficient conditions are obtained using delay-free sensing and control policies. These conditions quantify the effect of communication network parameters such as transmit powers, channel noise, and channel interference on the stability of the plant(s). Different settings where linear policies are optimal, asymptotically optimal (in certain parameters of the system) and suboptimal have also been identified. Part II considers the design of real-time sensing and control strategies for minimization of a quadratic cost function of the state process of a system over Gaussian networks. Two fundamental Gaussian networks are considered: i) cascade network and ii) parallel network. For each network, non-linear sensing and control schemes are proposed and sub-optimality of linear strategies is discussed.

    The results reveal fundamental limits on the performance of linear systems controlled over Gaussian networks. The methods used to derive these results reveal a close interplay between information theory and control theory.

  • 15.
    Zaidi, Ali Abbas
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Nasir Khormuji, Majid
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Yao, Sha
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Optimized mappings for dimension-expansion relaying2009In: SPAWC: 2009 IEEE 10TH WORKSHOP ON SIGNAL PROCESSING ADVANCES IN WIRELESS COMMUNICATIONS, NEW YORK: IEEE , 2009, p. 474-478Conference paper (Refereed)
    Abstract [en]

    We study the three-node Gaussian relay channel consisting of a source, a relay and a destination. We assume that the relay is memoryless, i.e., the transmitted signal from the relay depends only on the currently received signal. Additionally, we focus on dimension expansion relaying, where the relay has access to more channel uses for retransmission. We use the end-to-end mutual information to numerically optimize the relay mappings. We present several examples for two types of source input alphabets: continuous (Gaussian and uniform) and discrete (uniform PAM). The maximum rate attained by using the optimized mappings is considerably improved compared to conventional linear relaying.

  • 16.
    Zaidi, Ali Abbas
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Nasir Khormuji, Majid
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Yao, Sha
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Rate-Maximizing Mappings for Memoryless Relaying2009In: 2009 IEEE INTERNATIONAL SYMPOSIUM ON INFORMATION THEORY, NEW YORK: IEEE , 2009, p. 694-698Conference paper (Refereed)
    Abstract [en]

    We study the problem of optimal design of relay mappings for the Gaussian relay channel in order to maximize the reliable transmission rate. We consider both Gaussian and modulation constrained signaling at the source. To optimize the relay mapping, we use an iterative integral equation as a necessary condition for optimality. The optimized relay mappings demonstrate significant rate improvement over conventional linear relaying (amplify-and-forward). The optimized mappings allow an efficient utilization of the side information received via the source destination link at the destination. Hence, the proposed mappings can be considered as an analog, memoryless approach to implementing compress-and-forward relaying with Wyner-Ziv compression in the relay.

  • 17.
    Zaidi, Ali Abbas
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Nasiri Khormuji, Majid
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Yao, Sha
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Optimized analog network coding strategies for the white Gaussian multiple-access relay channel2009In: 2009 IEEE Information Theory Workshop, 2009, Vol. ITW 2009, p. 460-464Conference paper (Refereed)
    Abstract [en]

    We consider a Gaussian multiple-access relay channel with multiple sources, a relay and a destination. We assume that the received signals at the relay and the destination from different nodes are orthogonal. Additionally, we assume that the relay performs an instantaneous mapping to compress all received signals from different sources into one output symbol. We refer to this as analog network coding. We optimize the analog network coding mapping to maximize the achievable sum rate. We additionally introduce an algorithm to obtain an achievable rate region. The optimized mappings are in general non-linear and provide superior rates compared to those of linear mappings.

  • 18.
    Zaidi, Ali Abbas
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Serdar, Yuksel
    Mathematics and Statistics, Queen's University, Canada.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Stabilization of Linear Systems Over Gaussian Networks2014In: IEEE Transactions on Automatic Control, ISSN 0018-9286, E-ISSN 1558-2523, Vol. 59, no 9, p. 2369-2384Article in journal (Refereed)
  • 19.
    Zaidi, Ali Abbas
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    On stabilization over a Gaussian interference channel2013In: 2013 European Control Conference (ECC), IEEE , 2013, p. 2386-2391Conference paper (Refereed)
    Abstract [en]

    The problem of feedback stabilization of LTI plants over a Gaussian interference channel is considered. Two plants with arbitrary distributed initial states are monitored by two separate sensors which communicate their measurements to two separate controllers over a Gaussian interference channel under average transmit power constraints. The necessary conditions for mean square-stabilization over a memoryless symmetric Gaussian interference channel are derived. These conditions are shown to be tight for some system parameters. Further it is shown that linear memoryless sensing and control schemes are optimal for stabilization in some special cases.

  • 20.
    Zaidi, Ali Abbas
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Oechtering, Tobias J.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Yüksel, S.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Stabilization and Control over Gaussian Networks2014In: LCCC Workshop in Information and Control in Networks, 2014, p. 39-85Conference paper (Refereed)
    Abstract [en]

    We provide an overview and some recent results on real-time communication and control over Gaussian channels. In particular, the problem of remote stabilization of linear systems driven by Gaussian noise over Gaussian relay channels is considered. Necessary and sufficient conditions for the mean-square stabilization are presented, which reveal signal-to-noise ratio requirements for stabilization which are tight in a certain class of settings. Optimal linear policies are constructed, global optimality and sub-optimality of such policies are investigated in a variety of settings. We also consider the design of low-delay sensing and transmit schemes for real-time communication.

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