Sub-band exponential smoothing noise canceling system

  • US 6,377,637 B1
  • Filed: 07/12/2000
  • Issued: 04/23/2002
  • Est. Priority Date: 07/12/2000
  • Status: Expired due to Term
First Claim
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1. An apparatus for canceling noise by time domain processing sub-bands of a digital input signal, comprising:

  • input means for inputting a digital input signal which includes a noise signal;

    band splitting means for dividing said digital input signal into a plurality of frequency-limited time-domain signal sub-bands by using single side band modulation and a DFT filter bank;

    a plurality of noise processing means each for processing a corresponding one of said plurality of signal sub-bands such that said noise signal included in said digital input signal is cancelled;

    wherein each noise processing means is further comprised of exponential averaging means, noise estimating means, and subtraction processing means; and

    recombining means for recombining the noise processed plurality of signal sub-bands into a digital output signal.

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