This paper considers the noncooperative maximization of mutual information in the Gaussian interference channel in a fully distributed fashion via game theory. This problem has been studied in a number of papers during the past decade for the case of frequency-selective channels. A variety of conditions guaranteeing the uniqueness of the Nash Equilibrium (NE) and convergence of many different distributed algorithms have been derived. In this paper we provide a unified view of the state-of- the-art results, showing that most of the techniques proposed in the literature to study the game, even though apparently different, can be unified using our recent interpretation of the waterfilling operator as a projection onto a proper polyhedral set. Based on this interpretation, we then provide a mathematical framework, useful to derive a unified set of sufficient conditions guaranteeing the uniqueness of the NE and the global convergence of waterfilling based asynchronous distributed algorithms. The proposed mathematical framework is also instrumental to study the extension of the game to the more general MIMO case, for which only few results are available in the current literature. The resulting algorithm is, similarly to the frequency-selective case, an iterative asynchronous MIMO waterfilling algorithm. The proof of convergence hinges again on the interpretation of the MIMO waterfilling as a matrix projection, which is the natural generalization of our results obtained for the waterfilling mapping in the frequency-selective case.

Competitive Design of Multiuser MIMO Systems Based on Game Theory: A Unified View

Design procedures are proposed for two different classes of observers for systems withunknown inputs In thefirst approach, the state of the observed system is decomposed into known and unknown components The unknown component is a projection, not necessarily orthogonal, of the whole state along the subspace in which the available state component resides Then, a dynamical system to estimate the unknown component is constructed Combining the output of the dynamical system, which estimates the unknown state component, with the available state information results in an observer that estimates the whole state It is shown that some previously proposed observer architectures can be obtained using the projection operator approach presented in this paper The second approach combines sliding modes and the second method of Lyapunov resulting in a nonlinear observer The nonlinear component of the sliding mode observer forces the observation error into the sliding mode along a manifold in the observation error space Design algorithms are given for both types of observers

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Observer design for systems with unknown inputs

We present a novel event-based stereo matching algorithm that exploits the asynchronous visual events from a pair of silicon retinas. Unlike conventional frame-based cameras, recent artificial retinas transmit their outputs as a continuous stream of asynchronous temporal events, in a manner similar to the output cells of the biological retina. Our algorithm uses the timing information carried by this representation in addressing the stereo-matching problem on moving objects. Using the high temporal resolution of the acquired data stream for the dynamic vision sensor, we show that matching on the timing of the visual events provides a new solution to the real-time computation of 3-D objects when combined with geometric constraints using the distance to the epipolar lines. The proposed algorithm is able to filter out incorrect matches and to accurately reconstruct the depth of moving objects despite the low spatial resolution of the sensor. This brief sets up the principles for further event-based vision processing and demonstrates the importance of dynamic information and spike timing in processing asynchronous streams of visual events.

Asynchronous Event-Based Binocular Stereo Matching

This technical note presents a hybrid control scheme for the output-feedback control of switched linear systems with average dwell time. The proposed hybrid controller consists of a standard switching output-feedback control law and a supervisor enforcing a reset rule for the switching controller states at each switching instant. This hybrid control scheme provides an efficient and systema tic way for designing average dwell time switched linear control systems in the sense that the boundary condition can be incorporated into the synthesis problem in a convex formulation. Specifically, bo th full-order and reduced-order controllers with guaranteed stability and optimal weighted H1 performance will be solved by linear matrix inequality (LMI) optimizations. Simulation studies are included to illustrate the effectiveness of the proposed approach. Index Terms—Switching control; average dwell time; controller state reset; full-order and reduced-order controllers; LMI.

システム制御情報学会

Papers

システムと制御 = Systems and control