Patent ID: 8285554

Claim:
A method for aliasing suppression in a sub-band speaker-phone system, the method comprising the steps of: a. receiving an analog audio signal from a near end analog audio input interface, b. converting said analog audio signal into a near end digital audio signal using an A2D; c. receiving N≧2 sub-bands decoded digital audio data from a far-end, merging said N≧2 sub-bands decoded digital audio data into a wideband (WB) decoded digital audio data to be converted by D2A unit and provided to analog audio output interface; d. splitting said near-end digital audio signal into N≧2 near-end sub-bands digital audio signals; e. subtracting a simulated digital signal from each of said N≧2 sub-bands digital audio signal, wherein said simulated digital signal is created by an echo cancelling unit; and f. applying dynamic anti aliasing suppression (DAAS) with varying aggressiveness on each of said N≧2 near-end sub-band digital audio signals for suppressing an existing non linear aliasing component, wherein said varying aggressiveness is responsive to the activity of said far-end and the activity of said near-end analog audio input interface, and wherein said varying aggressiveness is defined at a predefined maximal level when only far-end is active, approximately zero when far-end is inactive and at a predefined intermediate levels of aggressiveness when both far-end and near-end are simultaneously active.