Patent ID: 6731690
Filing Date: 2004-05-04
Classification: H04J

Abstract:
A transmultiplexer for transmultiplexing a digitized signal sample produced by a converter, comprising:a first Fourier transformer coupled to the converter, said first Fourier transformer configured to transform said digitized signal sample produced by the converter into a frequency domain input signal; a frequency domain shifter coupled to said first Fourier transformer, said frequency domain shifter configured to frequency shift said frequency domain input signal to produce a shifted signal; a frequency domain pre-filter coupled to said frequency domain shifter, said frequency domain pre-filter configured to perform a first fast convolution with said shifted signal and a first discrete Fourier transform of a first filtering function, said frequency domain pre-filter configured to produce a filtered input signal; and a combining Fourier transformer coupled to said frequency domain pre-filter, said combining Fourier transformer configured to transform said filtered input signal produced by said frequency domain pre-filter, said combining Fourier transformer configured to produce an output signal containing a sample corresponding to a down-converted channel.