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.

公开(公告)号：US3573727A

公开(公告)日：1971-04-06

申请号：US3573727D

申请日：1968-11-04

Applicant: BELL TELEPHONE LABOR INC

Inventor： FREENY STANLEY L

IPC: G06F11/10 ,  G11B20/14 ,  H04L7/033 ,  H04L7/04 ,  H03K5/18 ,  H04B3/46 ,  H04L1/10

CPC classification number: G06F11/10 ,  G11B20/1403 ,  H04L7/033 ,  H04L7/048

Abstract: In a feedback circuit, the time at which a slicing circuit samples a received data signal is controlled to minimize the error rate in the digitized output signal. A parity check circuit controls a bistable multivibrator to provide a signal which repetitively varies the sampling time over a narrow range. The output of the bistable multivibrator is integrated to provide a signal which controls the sampling time over a wider range.

公开(公告)号：US3550021A

公开(公告)日：1970-12-22

申请号：US3550021D

申请日：1968-10-18

Applicant: BELL TELEPHONE LABOR INC

Inventor： FREENY STANLEY L

IPC: G11C27/02 ,  H04L25/49 ,  H03K5/00

CPC classification number: G11C27/02 ,  H04L25/4917