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Linear adaptive digital filters are applied to various fields for their simplicity in the design and implementation. Considering many kinds of nonlinearities inherent to practical systems, however, nonlinear adaptive filtering will be more desirable. In this paper, we present a design method for parallel nonlinear adaptive digital filters using multilayer nonrecursive neural networks. Linear adaptive digital filters with the advantage of obtaining better accuracy of estimation. Furthermore, the nonlinear adaptive digital filter is extended to parallel nonlinear adaptive digital filters which reduce the computations of each filtering system, especially when a high-order nonlinear adaptive digital filter is necessary. [ABSTRACT FROM AUTHOR]

This paper presents a design method for the equal-ripple, linear-phase FIR digital filter when the tolerance for the error of magnitude response in the passband or stopband is specified. To realize the design when various constraints are imposed on the transfer function or magnitude response, the design problem is formulated as the optimization problem. A solution method is shown to solve the problem using the constrained neural net. When the lower bound of the magnitude error in the stopband is set as zero in the proposed method, the filter with double zeros in the stopband can easily be designed. Examples of application are shown for the minimum-phase FIR filter and the matched filter pair with zero intersymbol interference. [ABSTRACT FROM AUTHOR]

Several methods have been presented recently for constructing the one-dimensional IIR digital filter by combining all-pass networks. It is known that the filter composed of the all-pass networks has a better computational efficiency and also low coefficient sensitivity due to the structural boundaries. In addition to the one-dimensional filters, a construction of the two-dimensional filter based on the all-pass network has also been proposed. A problem in that method, however, is the restriction on the realizable characteristics. This paper attempts to overcome that problem, and proposes a new construction of the two-dimensional digital filter using the all-pass network. The new approach employs the complex coefficient all-pass network instead of the conventional real-coefficient all-pass network. By this approach, the degree of freedom in the design is enhanced, and the characteristics which have been difficult or impossible to realize in the case of the real coefficient filters, are now made realizable. [ABSTRACT FROM AUTHOR]