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
Methods and systems for managing electronic messages
Automated gate system
Motion-compensated prediction of inter-layer residuals
Information-provision control method, information reproduction system, information-provision apparatus, information reproduction apparatus and information-presentation control program
System, method and computer program product for efficient caching of hierarchical items
Pelvic registration device for medical navigation
Continuously variable transmission and control method thereof
  Randomly Featured Patents
System and method for modeling the memory state of a streaming media server
Method of enhancing charge storage in an E.sup.2PROM cell
Circulating toy assembly
Baseball pitcher's eye training and game
Aerosol dispensing cabinet
Arrangement for providing vivid color in a television signal
Oxidative evaporation process and apparatus
Shaving organizer
Searching a document using relevance feedback
Soil filtration and water drainage device