Resources Contact Us Home
Chase algorithm based differential decoder for soft decision Reed Solomon decoding in a QAM system

Image Number 5 for United States Patent #8149925.

A novel apparatus and method of differential decoding for use in a communication system such as a cable system. The differential decoding mechanism of the present invention enables the use of the Chase algorithm for Reed Solomon (RS) codes (i.e. non-binary codes). The mechanism is well suited for use in systems employing QAM data modulation/demodulation techniques and that also incorporate use of a differential encoder such as in DOCSIS capable cable modem systems. The differential decoding mechanism is operative to analyze the input to the differential decoder and adjust the decoding action accordingly. The mechanism generates the first and second candidate constellation points needed by the Chase algorithm. Considering the differential encoding, there are four possible constellation candidates. The differential decoder reduces these four possible options to two by eliminating from consideration two of them. Depending on the number of symbols to be improved by the Chase algorithm, this reduction can potentially reduce the number of options significantly.

  Recently Added Patents
Optical modulation element
Sperm factor sequences
Method for dropping packet data, radio communication device, and mobile communication system
Position pointer, variable capacitor and inputting apparatus
PC secure video path
Universal handle extension for unloading butterfly valve for tank trailer or other vehicle
Lighting fixture
  Randomly Featured Patents
Cosmetic powder bar composition and process for making same
Electronic circuits for the generation of special effects in the visualization system of symbols on a kinescope especially for television games
Hop along doll
Vehicle backing aid
Coupling structure for a leaching chamber
Solid state binary logic signal source for electronic timepiece or the like
Gas shrouded wave improvement
Method and apparatus for setting game parameters
Stabilization of an image produced by optics