Kernel adaptive filter

About: Kernel adaptive filter is a research topic. Over the lifetime, 8771 publications have been published within this topic receiving 142711 citations.

Efficient implementation of all-digital interpolation

Abstract: B-splines are commonly used for continuous representation of discrete time signals. This kind of representation proves to be very useful in applications such as image interpolation, rotation and edge detection. In all these applications, the first step is to compute the B-spline coefficients of the signal, and this involves the use of an IIR noncausal filter called the direct B-spline filter. The signal reconstruction is achieved using the indirect B-spline filter, which in many applications operates at a higher rate. We introduce a simplified implementation of the signal reconstruction part that will significantly reduce the overall complexity. We also show that the direct B-spline filter can safely be replaced with a short FIR filter, without compromising the performance of the traditional method. Numerous examples show both visually and numerically that the differences between this method and the traditional one are indeed very small. Finally, we report the performance of these newly proposed methods in other image processing applications such as edge detection and least squares approximation.

Application of analog adaptive filters for dynamic sensor compensation

Abstract: This paper investigates the application of analog adaptive techniques to the area of dynamic sensor compensation, of which there is little reported work in the literature. The case is illustrated by showing how the response of a load cell can be improved to speed up the process of measurement. The load cell is a sensor with an oscillatory response in which the measurand contributes to the response parameters. Thus, a compensation filter needs to track variation in measurand, whereas a simple fixed filter is only valid at one specific load value. To facilitate this investigation, computer models for the load cell and the adaptive compensation filter have been developed. To allow a practical implementation of the adaptive techniques, a novel piecewise linearization technique is proposed in order to vary a floating voltage-controlled resistor in a linear manner over a wide range. Simulation and practical results are presented, thus, demonstrating the effectiveness of the proposed techniques.

Word-length optimization for high-level synthesis of digital signal processing systems

Abstract: Word-length optimization software is developed not only to reduce the hardware cost but also to minimize the optimization time. It inserts quantizers to a data flow graph representation, partitions the resultant graph, determines the minimum required word-length for each partitioned signal, conducts scheduling and binding using the minimum word-length information, and finally optimizes the word-lengths of functional units. Fixed-point simulation results are used as for the performance measure, thus this method can be applied to nonlinear and time-varying algorithms. Although this approach requires iterative fixed-point simulations, the search space is reduced significantly by grouping signals using the high-level synthesis, or hardware sharing, results. A fourth-order IIR filter, a fifth-order elliptic filter, and a 12th-order adaptive LMS filter are implemented using this software. The hardware cost of functional units is reduced by 25% in the IIR filter and 7% in the elliptic filter compared to the previous results.