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
Methods and apparatus for performing multiple photoresist layer development and etching processes
Medicament delivery device and a method of medicament delivery
Method and apparatus for communicating electronic service guide information in a satellite television system
Multibranched polymer and method for producing the same
ESD protection circuit and ESD protection device thereof
Simultaneous image distribution and archiving
System and method for deriving cell global identity information
  Randomly Featured Patents
Apparatus and method for processing a physical layer convergence protocol header
Boring tool for coarse and fine machining
Measuring audience viewership of online live broadcast
Dual type imaging device having multiple light sensitive elements
Tool for dispensing adhesives, sealants, and underfill materials
Key blank for an axial tumbler-type lock
Adjustable screw-type clamp
Projected image target apparatus
Bonding resins
Repair of film having an SI-O backbone