Signal processing circuit for creation of speaker signal in mobile radio terminal, has adaptation block using new coefficients in set of coefficients so that resulting transfer functions of filters are provided inverse to each other

摘要

The circuit has a digital filter block (SPM) producing an estimation signal (Y) in dependent upon a measuring signal (X). The block comprises a recursive filter (HRES) of second order, which is determined by an adjustable set of coefficients (A1, A2, B1, B2). An adaptation block (RAA) determines a new set of coefficients based on the measuring signal, the estimation signal and an filtered input signal (AINF) and uses the new coefficients in the set of coefficients such that the resulting transfer functions of the filter and another recursive filter (HEQ) are provided inverse to each other. An independent claim is also included for a signal processing method for creation of a speaker signal.