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
Coreference resolution in an ambiguity-sensitive natural language processing system
Semiconductor memory apparatus
Packet transmission method, apparatus, and network system
Wristband with detachable labels
Spoofing detection for civilian GNSS signals
Electrical stimulation lead, system, and method
Emergency power-off button with proximity alarm
  Randomly Featured Patents
Deep heating magnetic wrap for joints and tissue
Control method for switching power supply circuit
Control circuit means for controlling the after-running of an operating device in a motor vehicle
Operation method to operate tilt sensor
Controller and control method for a hybrid electric vehicle powertrain
Air-conditioner housing
Book binding system
Lamp brightness remote controlling device
Ergonomically improved arm portal and pass box assembly
Deflickering and scaling scan converter circuit