Patent ID: 6396872
Filing Date: 2002-05-28
Classification: H03H

Abstract:
In an unknown system identification method supplying an input signal to an unknown system and simultaneously generating a plurality of subband signals by dividing an input signal into subbands, supplying said plurality of subband signals as input signals to independent adaptive filters, generating a plurality of subband reference signals by dividing an output signal of said unknown system into subbands, making the difference between said plurality of subband reference signals and the output signal of said adaptive filter as a subband error signal, updating coefficients of said adaptive filter using coefficient adaptation algorithm of an adaptive filter so as to minimize said subband error signal, and regarding an updated coefficients as the impulse response of an unknown system,said unknown system identification method comprising the steps of: calculating an approximate number of taps of said independent adaptive filters based on coefficient values of said independent adaptive filters, the numbers of taps of said independent adaptive filters, the output signal of said subband unknown system and said plurality of subband input signals, calculating an optimum number of taps of said independent adaptive filters based on coefficient values of said independent adaptive filters, said plurality of subband input signals and the numbers of taps of said independent adaptive filters, assigning an initial number of taps to said independent adaptive filters, assigning said calculated approximate numbers of taps to said independent adaptive filters after a first predetermined time passing, and assigning said calculated optimum number of taps to said independent adaptive filters after a second predetermined time, and wherein the increment or decrement of number of taps among said independent adaptive filters at one tap-redistribution is adaptively controlled by continuous changes of the increment or decrement of taps in each adaptive filter.