Resources Contact Us Home
Method and apparatus for DC restoration in digital receivers

Image Number 5 for United States Patent #4873702.

A technique for eliminating unwanted dc offset voltages in a receiver for decoding a plurality of multilevel digitally modulated signals. The data transmission system is arranged to send a particular preamble signal each time a different data source begins transmission of its data. The preamble signal produces at the receiver output multiple cycles of maximum level excursions. During the period of time that the preamble signal is received, a signal processor in the receiver determines an initial dc offset value by averaging the level of the received digitally modulated signal. After the transmission of the preamble, the signal processor continually generates updated dc offset voltages which are equal to the sum of the previously generated dc offset voltage and the difference between the amplitude level represented by the received digitally modulated signal and the amplitude level of the closest "coding" amplitude level; the difference being multiplied by a scaling factor. Once a scaling factor is applied to the updated dc offset value, the result is added to the previous dc offset voltage. And, the process is continually repeated to produce updated dc offset voltages.

  Recently Added Patents
Mobile terminal and controlling method thereof
Gas sensor with a porous layer that detectably affects a surface lattice resonant condition of a nanoparticle array
Dynamic data caches, decoders and decoding methods
Method and apparatus for charging a power pack of a portable electronic device
Method for detecting security error in mobile telecommunications system and device of mobile telecommunications
Simultaneous wafer bonding and interconnect joining
Encoding method, decoding method, encoding device, decoding device, program, and recording medium
  Randomly Featured Patents
Magnetic carrier
Cruciate ligament surgical drill guide
All-in-one golf tool
Up-converting reporters for biological and other assays
Descent with manually operable brake
Refill bottle
Multi-size convertible catheter
Organic electric field light-emitting element
Method and apparatus for molding expandable polystyrene foam articles
Device for generating line-shaped light beam and laser microscope