公开(公告)号：US3593142A

公开(公告)日：1971-07-13

申请号：US3593142D

申请日：1969-11-20

Applicant: BELL TELEPHONE LABOR INC

Inventor： FREENY STANLEY L ,  KING BERNARD G ,  PEDERSEN THOMAS J

IPC: H04B3/04 ,  H04L5/04 ,  H04L25/03 ,  H04L25/48 ,  H04B1/00

CPC classification number: H04L5/04 ,  H04L25/03038

Abstract: A transmission system for transmitting multilevel digital signals over an analog band limited transmission medium. The digital signals to be transmitted are predistorted by a transversal preequalizer located at the transmitter which operates under the control of equalizer correction signals derived from the output of an analog-to-digital encoder at the receiver; which signals are sent from the receiver to the transmitter over a relatively low-speed signaling or reverse channel. After such predistortion the multilevel signals are transmitted using vestigial sideband techniques so that digital apparatus is required only in the transmitter and receiver with none required at intermediate points.