Resources Contact Us Home
Compander for TDM telecommunication system

Image Number 2 for United States Patent #3943466.

Amplitude samples of voice signals to be transmitted by pulse-code modulation are compared with a quasi-exponential reference voltage generated during each sampling interval while a binary counter receives a train of isochronous clock pulses, the reading of the counter at the instant of a match being stored in a memory for subsequent insertion into a message frame. Positive and negative signals are distinguished by a sign bit preceding the amplitude code; in one embodiment the reference voltage is sequentially generated with opposite polarities in successive halves of a sampling interval, the counter having an additional stage to generate the sign bit. Decoding at the receiving end is achieved with the aid of another binary counter whose output is compared with the amplitude code and, in the event of a match, causes the instantaneous value of a similar reference voltage to be sampled and stored for subsequent integration.

  Recently Added Patents
Adaptive block pre-fetching method and system
Apparatus and method for multiple pagings in broadband wireless communication system
Push mechanism for efficiently sending aggregated data items to client
Data recording apparatus with recording control based on defect block and control method thereof
Biomarker for Barrett's Oesophagus
Nonvolatile semiconductor memory device and method for controlling the same
Method for providing interactive site map
  Randomly Featured Patents
Terminal device, game control method, information recording medium, and program
Tractor loader backhoe with rotatable cab
Folding wing structure for missile
Module for a medication injection device
Mechanically-attached nosebridge element for eyewear frame
Chairs with foldable backs
Bi-functional plasmid that can act as both a DNA vaccine and a recombinant virus vector
Trellis modulation protocols for a VDSL system
Method for determining vehicle status variables
Roof structure for a rigid, openable vehicle roof