Patent ID: 7227902

Claim:
A method for extracting a channel from a data stream using a modified fast convolution algorithm, said modified fast convolution algorithm consisting of a common-channel part followed by a channel-specific part, said channel-specific part comprising the steps of: selecting a range of n Discrete Fourier Transform bins around the center frequency of the channel; multiplying said bins with a frequency response; performing an N IDFT -point Inverse Discrete Fourier Transform on these n data points; and, performing a signal processing step; wherein said common-channel part of said modified fast convolution algorithm comprises the step of performing a N FFT -Point Fast Fourier Transform on overlapping blocks of said data stream; and, wherein said N FFT -point Fast Fourier Transform in said common-channel part of said modified fast convolution algorithm is preceded by the steps of: first, processing said data stream by a η % overlap block generator; second, multiplexing said data stream to form a complex signal; wherein said channel-specific part of said modified fast convolution algorithm further comprises the steps of: a first step of performing extraction of said bins; a second step of performing said multiplication of said bins with said frequency response; a third step of performing an N IDFT -point Inverse Discrete Fourier Transform on these n data points; and, a fourth step of processing said digital data stream by a η % overlap block combiner.