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  • 【期刊】 Yasamin Mostofi [People in Control]

    作者:None 年份:2010
    摘要:http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=5466144
  • 【期刊】 Compressive Cooperative Obstacle Mapping in Mobile Networks

    作者:Yasamin Mostofi ; Alejandro Gonzalez-Ruiz 关键词:Approaches; Mobile Networks; obstacle map; wireless channel; wireless measurements; proposed framework 机构:Department of Electrical and Computer Engineering ; Department of Electrical and Computer Engineering ; University of New Mexico 年份:2010
    摘要:In this paper we consider a mobile cooperative network that is tasked with building an obstacle map in an environment. We propose a framework that allows the robots to build the obstacle map non-invasively and with a small number of wireless channel measurements. By extending our previous work on sparse obstacle mapping, we show how the nodes can exploit the sparse representation of the map in order to build it with minimal sensing. The proposed work allows the robots to efficiently map an area before entering it. We propose two approaches based on random and coordinated wireless measurements. Our simulation and experimental results show the superior performance of the proposed framework.
  • 【期刊】 Kalman filtering over wireless fading channels—How to handle packet drop

    摘要:In this paper we consider estimation of dynamical systems over wireless fading communication channels using a Kalman filter. We show the impact of the stochastic communication noise on the estimation process. We furthermore show how noisy packets should be handled in the receiver. More specifically, we illustrate the impact of the availability of a cross-layer information path on the optimum receiver design. In the absence of a cross-layer information path, it was shown that packet drop should be designed to balance information loss and communication noise in order to optimize the performance. In the presence of a cross-layer path, we show that keeping all the packets will minimize the average estimation error covariance. We also derive the stability condition in the presence of noisy packets and show that it is independent of the shape of the communication noise variance or availability of a cross-layer information path. Copyright copy 2008 John Wiley & Sons, Ltd.
  • 【期刊】 Communication and sensing trade-offs in cooperative mobile networks

    作者:Yasamin Mostofi ; Richard M. Murray 关键词:Cooperative networks ; sensor networks ; communication noise ; distributed sensing and control 机构:Department of Electrical and Computer Engineering, MSC01 1100, 1 University of New Mexico, Albuquerque, NM 87131‐0001, USA;Department of Electrical and Computer Engineering, MSC01 1100, 1 University of New Mexico, Albuquerque, NM 87131‐0001, USA;Control and Dynamical Systems 107‐81, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA; ; Department of Electrical and Computer Engineering, MSC01 1100, 1 University of New Mexico, Albuquerque, NM 87131‐0001, USA;Department of Electrical and Computer Engineering, MSC01 1100, 1 University of New Mexico, Albuquerque, NM 87131‐0001, USA;Control and Dynamical Systems 107‐81, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA; 年份:2008
    摘要:

    Abstract

    In this paper we consider the impact of communication noise on distributed sensing and estimation in mobile networks. We characterize when a node should rely on getting information from others and when it should rely on self exploration. In doing so, we explore the trade-offs between sensing and communication by finding the optimum network configuration under communication constraints. We also show how to achieve the optimum configuration in a distributed manner. While our main results are presented in one dimension (1D), we provide insight into the two dimension (2D) setup and extend a number of key results to 2D. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society

  • 【期刊】 Decentralized Communication-Aware Motion Planning in Mobile Networks: An Information-Gain Approach

    作者:Yasamin Mostofi 年份:2009
    摘要:http://link.springer.com/article/10.1007%2Fs10846-009-9335-9
  • 【会议】 Distributed Sensing and Estimation Under Communication Constraints

    摘要:In this paper we consider the impact of imperfect communication links on distributed sensing and estimation in mobile networks. First we will find optimum sensing regions and sensor positions under communication constraints. We will show that the optimum sensor configuration consists of overlapping sensing regions. We will then show how the nodes can achieve the optimum configuration in a distributed manner.
  • 【会议】 An optimal control approach for communication and motion co-optimization in realistic fading environments

    摘要:We consider an energy co-optimization problem of minimizing the total communication and motion energy of a robot tasked with transmitting a given number of information bits while moving along a fixed path. The data is transmitted to a remote station over a fading channel; which changes along the trajectory of the robot. While a previous approach to the problem used a speed-based motion-energy model; this paper uses acceleration both as an input to the system and as a basis for the motion energy which is more realistic. Furthermore; while previous approaches posed the problem in discrete time; we formulate it in continuous time. This enables us to pose the problem in an optimal control framework amenable to the use of maximum principle. We then compute the optimal control input via an effective algorithm recently developed by us that converges very fast. We use practical models for channel fading and energy consumption: the channel quality is predicted based on actual measurements; and the energy models are based on physical principles. Simulation is used to solve a specific problem and demonstrate the efficacy of our proposed approach.
  • 【会议】 Receiver Design Principles for Estimation over Fading Channels

    摘要:In this paper we consider estimation of dynamical systems over wireless communication channels. We show that the communication protocols suitable for non real-time applications like data networks may not be entirely applicable for estimation and control of a rapidly changing dynamical system. We then develop new design paradigms for these applications to show how noisy packets should be handled in the receiver. We prove that; in the presence of a crosslayer feedback; keeping all the packets will both maximize the stability range and minimize the estimation error variance. In the absence of such a feedback; we show that keeping all the packets still maximizes the stability range; independent of the shape of the communication noise profile. In order to optimize the performance; in the absence of a cross-layer feedback; we prove that packet drop should be designed to balance information loss and communication noise.
  • 【会议】 Effect of Narrowband Channels on the Control Performance of a Mobile Sensor Node

    作者:Yasamin Mostofi ; Richard M. Murray 年份:未知
    摘要:In mobile sensor networks; sensor measurements as well as control commands are transmitted over wireless time-varying links. It then becomes considerably important to address the impact of imperfect communication on the overall performance. In this paper; we study the effect of time-varying communication links on the control performance of a mobile sensor node. In particular; we investigate the impact of fading. We derive key performance measure parameters to evaluate the overall feedback control performance over narrowband channels. We show that fading can result in considerable delay and/or poor performance of the mobile sensor depending on the system requirements. To improve the performance; we then show how the application layer can use the channel status information of the physical layer to adapt control commands accordingly. We show that sharing information across layers can improve the overall performance considerably. We verify our analytical results by simulating a wireless speed control problem.
  • 【期刊】 ICI mitigation for pilot-aided OFDM mobile systems

    刊名:IEEE Trans. Wireless Communications 作者:Yasamin Mostofi ; Donald C. Cox 关键词:NTS;Pilot;OFDM;Doppler Spread;ICI 年份:未知
    摘要:Orthogonal frequency-division multiplexing (OFDM) is robust against frequency selective fading due to the increase of the symbol duration. However, for mobile applications channel time-variations in one OFDM symbol introduce intercarrier-interference (ICI) which degrades the performance. This becomes more severe as mobile speed, carrier frequency or OFDM symbol duration increases. As delay spread increases, symbol duration should also increase in order to maintain a near-constant channel in every frequency subband. Also, due to the high demand for bandwidth, there is a trend toward higher carrier frequencies. Therefore, to have an acceptable reception quality for the applications that experience high delay and Doppler spread, there is a need for ICI mitigation within one OFDM symbol. We introduce two new methods to mitigate ICI in an OFDM system with coherent channel estimation. Both methods use a piece-wise linear model to approximate channel time-variations. The first method extracts channel time-variations information from the cyclic prefix. The second method estimates these variations using the next symbol. We find a closed-form expression for the improvement in average signal-to-interference ratio (SIR) when our mitigation methods are applied for a narrowband time-variant channel. Finally, our simulation results show how these methods would improve the performance in a highly time-variant environment with high delay spread.
  • 【会议】 Channel Learning and Communication-Aware Motion Planning in Mobile Networks

    摘要:In this paper we propose a communication-aware motion planning framework to ensure robust cooperative operation of a mobile network in realistic communication environments. We use a probabilistic multi-scale model for channel characterization. We then utilize our previously proposed model-based channel prediction framework in order to devise communication-aware motion-planning approaches. We first propose a motion generation strategy that optimally plans the trajectory of the robot in order to improve its channel learning in an environment. We then propose a communicationaware navigation approach in which link quality predictions are combined with sensing goals in order to ensure cooperative and networked task accomplishment. Our simulation results show the superior performance of our proposed communicationaware motion planning framework.
  • 【会议】 Compressive cooperative obstacle mapping with see-through capabilities in mobile networks

    摘要:Mobile intelligent networks can play a key role in many different areas from emergency response; surveillance and security; and battlefield operations to smart homes and factories and environmental monitoring. Accurate mapping of the obstacles/objects in the environment is key to the robust operation of unmanned autonomous networks as it is an integral part of navigation and path planning. In the robotics community; the problem of mapping has been widely explored. However; in the existing mapping approaches; only areas that can be directly sensed by the sensors are mapped. In several scenarios; it may be necessary to have see-through capabilities and map occluded objects without direct sensing. For instance; the robots may need to build an understanding of the objects inside a room before entering it. Having see-through capabilities can also reduce the overall mapping time and energy in any networked robotic operation. In this dissertation; we consider a mobile robotic network that is tasked with building a map of the objects/obstacles in an environment including the occluded ones. Since we