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
Curable inks comprising surfactant-coated magnetic nanoparticles
Hand-held optical probe based imaging system with 3D tracking facilities
Method and apparatus for storing email messages
Hydrofluorocarbon refrigerant compositions for heat pump water heaters
Reactor core of liquid metal cooled reactor
Gangable electrical box and leveling assembly
Synthetic refrigeration oil composition for HFC applications
  Randomly Featured Patents
Pipe polishing apparatus and method
Plate fin coil assembly
Apparatus and method for inspecting overlapping figure, and charged particle beam writing apparatus
Collaborative diagnostic systems
Communication processing system, communication processing method, server and computer program
Back frame lockout via cushion
Application of dry spreadable water dispersible granule compositions
Seed index system for treating agricultural seeds
Optimum resource allocation method and system in medium access control of distribute scheme in wireless personal area network
Connecting rod bearing for internal combustion engines and connecting rod bearing device