Abstract: A method to denoise a stereo signal comprising a stereo sum signal and a stereo difference signal, performs a frequency selective stereo to mono blending based on the masking effect of the human auditory system. Therefore, a stereo signal noise reducer, comprising a first filter bank (1) to split the stereo difference signal (1−r) into a plurality of subbands, respective first multipliers (20, . . . , 2N) to weight each of the subbands of the stereo difference signal with a respective corresponding control signal (C0, . . . , CN), and a first adder (3) to sum all weighted subbands of the stereo difference signal (1−r) to build a frequency selective weighted stereo difference signal (diff), within which a number and width of the subbands obtained via the first filter bank (1) are choosen according to the properties of the human auditory system, further comprises a weighting factor determination unit which determines a respective control signal (C0, . . .

Abstract: A polyphase filter of order x.N that is building N allpass filters of order x.N according to the present invention has a structure of an allpass filter of order x comprising delay elements with a delay 1 and at least one multiplier, wherein all delay elements with a delay of 1 are replaced by delay elements with a delay of N and the sampling rate of fs′=fs/N with fs being the sampling rate of the input signal.

Abstract: A method and device for digitally demodulating a frequency modulated signal includes: calculating a phase of a digital complex baseband signal of a received frequency modulated signal, calculating an unwrapped phase of the calculated phase, detecting and eliminating 2.pi. phase jumps in the unwrapped phase to generate a corrected phase, and differentiating the corrected phase.