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
Input device with photodetector pairs
Measurement of an analyte on the skin using a hue angle
Preparation and use of meristematic cells belonging to the Dendrobium phalaenopsis, Ansellia, Polyrrhiza, Vanilla, Cattleya and Vanda genera with high content of phenylpropanoids, hydrosoluble
System and method for computational unification of heterogeneous implicit and explicit processing elements
Data processing method
Method and apparatus for controlling a multi-node process
RF power amplifier circuit with mismatch tolerance
  Randomly Featured Patents
Ported aerodynamic exhaust tailpipe
Server computer for selecting program updates for a client computer based on results of recognizer program(s) furnished to the client computer
Electrical junction box
Selectively actuable magnetic head
Fluorine-containing polymerizable monomer and polymer compound using same
CXC chemokines as regulators of angiogenesis
Image reading device configuration for an image reading unit and a document holder
Method and device for telephone number search in a mobile terminal
AC fan motor driving circuit having detecting current wave capability
Pulse precursor deposition process for forming layers in semiconductor devices