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ABSTRACT: The myriad filter has demonstrated to be a robust countermeasure against the negative effect that impulsive noise has over electronic systems. However, its use is still limited in systems where processing speed is critical, as is the case of radar, sonar, and real-time audio and video processing. This limitation has its roots in the challenges imposed by the numerical approximation of the myriad filter. In particular, minimization operations at the interior of nonlinear operations are sensitive components that have a direct impact on the performance of the filtering algorithms. In the case of the myriad filter, the minimization of functions with multiple local minima is a common operation, and poorly chosen algorithms compromise the good behavior of the filter. In this correspondence, we present an alternative for the minimization of the objective function in the computation of the myriad filter. This solution exploits general concepts in global optimization and adapts them to the particular case of myriad filtering. This technique improves accuracy and speed in the computation of the myriad filter, making the method feasible in many problems.
IEEE Transactions on Signal Processing 08/2008; · 2.63 Impact Factor
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IEEE Transactions on Signal Processing. 01/2008; 56:3340-3346.
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ABSTRACT: Active queue management (AQM) schemes proposed to date use control mechanisms having fundamental weaknesses often leading to overparameterization and instabilities. This paper draws from the rich theory of dithering and quantization, extensively used in signal processing, to develop new marking and control mechanisms that overcome such limitations. In particular, a packet marking mechanism is developed through error diffusion filtering where congestion is measured and controlled through the instantaneous queue, the derivative of the queue length, and an estimate of the number of active flows. The proposed mechanism, referred to as DM (diffusion marking), is able to maintain a desired average queue length even under rapid changes in the traffic dynamics with surprisingly short lived queue size transients. DM provides a consistent low link delay without sacrificing throughput and is shown to outperform RED, REM, and AVQ type AQM mechanisms in varying network conditions with a significant improvement in stability.
Communications, 2005. ICC 2005. 2005 IEEE International Conference on; 06/2005
