A novel design of FIR (finite impulse response) filter named APNPBF (all-phase narrow passband filter) was proposed based on all-phase theories. The APNPBF can provide the passband gain with high precision and can satisfy the required specifications without repeatedly modifying the design. The frequency sampling, Chebyshev window and all-phase narrow pass-band filters were applied as the kernel of the prediction algorithm of protein coding regions respectively. The prediction results measured with AC (approximate correlation) at the base level of DNA sequences from data sets HMR195 and ALLSEQ proved the superiority of the proposed method.

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