Technique for achieving the full coding gain of encoded digital signals
AssigneeAT&T Bell Laboratories
InventorsAhmad K. Aman, Robert L. Cupo, Nicholas A. Zervos
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Abstract
In a telephone local loop transmission arrangement, data is communicated from the customer premises to the central office utilizing a multi-dimensional, passband signal illustratively at 480 kb/s. Specifically, the transmitted signal is encoded in a trellis code and precoded using a generalized partial response filter. The received signal is processed by a circuitry that implements a trellis decoding in combination with nonlinear filtering.
Claims8
Apparatus for transmitting a data signal which represents information, said data signal being corrupted by noise which is substantially colored after propagating through a communications medium, said apparatus comprising
- means for encoding said information using a code, the utilized code providing the encoded information having improved immunity to white noise relative to the uncoded information, and
- means for nonlinearly processing said encoded information in such a manner that distortion associated with subsequent whitening of said noise in receiver apparatus is reduced.
A method for transmitting a data signal which represents information, said data signal being corrupted by noise which is substantially colored after propagating through a communications medium, said method comprising the steps of
- encoding said information using a code, the utilized code providing the encoded information having improved immunity to white noise relative to the uncoded information, and
- nonlinearly processing said encoded information in such a manner that distortion associated with subsequent whitening of said noise in receiver apparatus is reduced.
Dependencies are inferred from the claim text.