ADAPTIVE FIR FILTER OF GENERALIZED SUB-BAND DECOMPOSITION STRUCTURE USING SUB-FILTER HAVING WAVELET CONVERSION AND DYADIC SPARSITY FACTOR

摘要

PURPOSE: An adaptive FIR(Finite Impulse Response) filter of a generalized sub-band decomposition structure using a sub-filter having wavelet conversion and a dyadic sparsity factor is provided to accord with a response characteristic of a sub-filter with a frequency pass band of wavelet conversion by changing sparsity factors of a sub filter according to a wavelet conversion level. CONSTITUTION: A delay portion(2) delays an input signal and outputs the delayed signal. An M point DWT(Discrete Wavelet Transform) matrix interpolator(3') receives and converts a time area signal and outputs the converted signal. A buffer memory(4) performs a function of a FIFO memory for storing temporarily a wavelet conversion signal of the interpolator(3'). A DSF(Dyadic Sparsity Factor) sub-filer(5') processes output data of the buffer memory(4) according to an adaptive signal. An adder(9) generates an output signal corresponding to the input signal by summing up outputs of the DSF sub-filter(5'). An adder(10) generates an error value between an output signal of the adder(9) and a request signal. A calculator(9) receives an error detection signal from the adder(10) and generates an adaptive control signal to the DSF sub-filter(5').