Interference canceling method based on improved all-pass fractional delay filter

Abstract

The invention belongs to the technical field of digital filter design and in particular relates to an interference canceling method based on an improved all-pass fractional delay filter. The interference canceling method comprises the specific steps of utilizing a minimum mean square error criterion to construct a mathematic model of the all-pass fractional delay filter, utilizing a particle swarm optimization method based on natural selection to solve the mathematic model of the all-pass fractional delay filter and further construct the all-pass fractional delay filter, obtaining reference signals, utilizing the constructed all-pass fractional delay filter to filter the reference signals and carrying out interference canceling process on the filtered signals and signals received by a radar. The interference canceling method uses a natural-selection particle swarm algorithm, guarantees the solving convergence of the filter, quickens the convergence speed, avoids complex numeric calculation, guarantees the solving numerical stability of the all-pass fractional delay filter and enables design of the variable fractional delay filter to be more flexible.

Description

technical field [0001] The invention belongs to the technical field of digital filter design, in particular to an interference cancellation method based on an improved all-pass fractional delay filter. Background technique [0002] Fractional sample time delays are used in a wide variety of fields, including: delay adjustment for digital receivers, beam steering for array radars, speech coding and synthesis, instrument calibration, sample rate conversion, delay estimation, comb filter design, and A / D transform and so on. At present, the most commonly used method is the design method of the all-pass fractional delay filter. For the design of the all-pass fractional delay filter, the filter coefficients are polynomially fitted to minimize the weighted mean square (WLS: Weighted Least Square ) error as the criterion for the optimal design of the fractional delay filter. Generally, there are two methods to solve the optimal weight value, which are iterative method and non-ite...

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Problems solved by technology

Whether iterative or not, the traditional numerical optimization solution of the fractional delay filter is applied to matrix inversion and numerical integration, and the complexity of matrix inversion operation becomes very high when the order of the filter is high, so the numerical integration only A better approximation effect can only be obtained when the filter order is low

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