Interference Cancellation 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 cancellation method based on an improved all-pass fractional delay filter. The specific steps are: adopting the minimum mean square error criterion to construct an all-pass fractional delay filter Mathematical model; adopt the particle swarm optimization method based on natural selection to solve the mathematical model of described all-pass type fractional delay filter, and then construct all-pass type fractional time-delay filter; Obtain reference signal, utilize the all-pass type that constructs The type fractional delay filter performs filtering processing on the reference signal, and performs interference cancellation processing on the filtered signal and the signal received by the radar. The present invention adopts the particle swarm algorithm of natural selection, which ensures the convergence of the solution of the filter, accelerates the convergence speed, does not require complicated numerical calculations, and ensures the numerical stability of the solution of the all-pass fractional time-delay filter. Variational fractional delay filter design is 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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