Patent ID: 7971225
Filing Date: 2011-06-28
Classification: H04N

Abstract:
1. A signal encoder for use in a cable television return path and configured to receive a first stream of digital samples from an analog-to-digital converter, the first stream of digital samples being representative of an analog return path signal that is sampled at a first data rate, the signal encoder comprising: a bandpass interpolation filter configured to receive the first stream of digital samples and to substantially remove signals outside of a predetermined frequency band; up-sampling logic configured to up-sample outputs of the bandpass interpolation filter and to generate a second stream of digital samples at a second data rate, the second data rate being a predetermined multiple of a center frequency of the predetermined frequency band; separation logic configured to separate the second stream of digital samples into a third stream of digital samples and a fourth stream of digital samples, the third stream and the fourth stream each having a data rate that is one half of the second data rate; a first interpolation filter configured to interpolate the third stream; a second interpolation filter configured to interpolate the fourth stream; and down-sampling logic configured to select digital samples from the outputs of the interpolation filters and to interleave the selected digital samples to form a fifth stream of digital samples, the fifth stream having a third data rate that is higher than four times the bandwidth of the predetermined frequency band but lower than the first data rate.