公开(公告)号：DE3172119D1

公开(公告)日：1985-10-10

申请号：DE3172119

申请日：1981-05-25

Applicant: IBM

Inventor： ABRAMSON PAUL

IPC: H04M11/06 ,  H04J3/06 ,  H04L5/14 ,  H04L5/16 ,  H04L7/033 ,  H04L7/04 ,  H04L25/02 ,  H04M11/00 ,  H04Q11/04

Abstract: Bi-directional communications system in which a first polarity of pulses is utilized for communication of traffic in one direction, traffic in the return direction utilizing pulses of the opposite polarity. Each end of the communication link has both a sender (4) and a receiver (5). One sender (4) arbitrarily transmits only positive pulses and the receiver (5) at this end of the system recognizes only negative pulses. The inverse set of conditions is enforced at the opposite end of the link. Means are included for synchronizing the application of pulses to the link at the other end in response to the receipt of pulses at that end to avoid overlap of receive pulses at the originating end of the line.

公开(公告)号：CA1066824A

公开(公告)日：1979-11-20

申请号：CA247256

申请日：1976-03-02

Applicant: IBM

Inventor： ABRAMSON PAUL ,  APPEL ULRICH

IPC: H04J3/17 ,  H04B3/20 ,  H04J6/02

Abstract: DIGITAL VOICE SIGNALING WITH DIGITAL ECHO DETECTION AND VOICE ACTIVITY COMPRESSION USED TO CANCEL ECHO A connection system for varied distance digital communication capable of handling telephone signals utilizes Voice Activity Compression (VAC) to effectively share a given number of digital transmission channels among a greater number of virtual telephone connections. The telephone signals are delta-modulated and demodulated in system connection stations. The VAC processing circuits with a small increment of decision logic provide echo suppression. Echo suppression is thereby rendered as a "value-added" service at a relatively small increment of station cost over the cost of VAC processing. Echo interference with original telephone signal activity in the send channels is reduced by digital control of gain in the demodulation stage. The system also provides connections without VAC handling subject to echo control.

公开(公告)号：CA940206A

公开(公告)日：1974-01-15

申请号：CA129325

申请日：1971-12-06

Applicant: IBM

Inventor： ABRAMSON PAUL ,  GOERTZEL GERALD

IPC: H04Q1/457

Abstract: A parallel tone detection method, system and apparatus includes using several generators for providing square waves at the fundamental frequency of several parallel tones to be detected. An unknown input signal is clipped and then AND gates are used to test for the simultaneous presence of the A.C. polarities of both the unknown input signal and each respective square wave. A low-pass filter is connected to each of the outputs of the AND gates associated with each tone. The outputs of the filters for each tone are connected into a corresponding analogue OR gate, which is one of a series of analogue OR gates. Then it is determined whether the outputs of any of the analogue OR gates exceeds a standard value. If it does then a circuit determines which analogue OR gate produces the largest output to identify the tone received.

公开(公告)号：DE1791072A1

公开(公告)日：1971-10-21

申请号：DE1791072

申请日：1968-09-06

Applicant: IBM

Inventor： ABRAMSON PAUL ,  KENNEDY FRENCH WALTER

IPC: G01R19/22

Abstract: 1,175,948. Detector circuits. INTERNATIONAL BUSINESS MACHINES CORP. 27 Aug., 1968 [14 Sept., 1967], No. 40820/68. Heading H3T. A signal detection circuit comprises means for chopping an input signal to produce a sequence of discrete pulses, means for differentiating the pulses to produce a sequence of spike pulses and means for smoothing the latter to produce a unipolar output signal having an amplitude level representative of the amplitude of the input signal. A signal A, Fig. 2, is applied over capacitor 10, Fig. 1, to the source 14 of field effect transistor, the gate 18 of which is driven with a square waveform B, to produce a chopped waveform C at the drain. This is differentiated in differentiating circuit comprising capacitor 24 and resistor 26 to produce the spike waveform D. This is applied to the base of transistor 28, the negative-going spikes causing conduction in the transistor, the collector potential of which is smoothed by means of R, C circuit 30, 32 to produce at terminal 34 a relatively steady signal E representative of the amplitude of the input signal.

公开(公告)号：DE1437699A1

公开(公告)日：1968-10-24

申请号：DE1437699

申请日：1965-04-07

Applicant: IBM

Inventor： ABRAMSON PAUL ,  WILLIAM BENETT RICHARD ,  HEIGHTS YORKTOWN ,  RAYMOND STILWELL JUN GEORGE

IPC: G08C15/06 ,  H01H36/00 ,  H01H51/28 ,  H01H67/06 ,  H03K3/45

Abstract: 1,073,054. Selective signalling. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 22, 1965 [April 20, 1964], No. 12006/65. Heading G4H. At a central station, a magnet (12), Fig. 1 (not shown) is rotated 4 times as fast as a magnet (32), so that while one of reed switches (41, 43, 45, 47) is closed by magnet (32), pulses are induced in coils (21-23) by magnet (12), and while one of reed switches (42, 44, 46, 48) is closed, pulses are induced in coils (24-26). The pulses from coils (21-23) scan three switches (101-103) at each of four remote stations (A-D), but since only one switch (41, 43, 45, 47) is closed at a time the signals from one station (A-D) at a time are passed to output (72). The pulses from coils (24-26) provide binary coded indications of the respectiveremote station identities by way of diodes (122- 128) and switches. (42, 44, 46, 48), only one of which can be closed at a time, the identity pulse train following the data from the respective remote station. In Fig. 2 (not shown) pulses from coils (21-26) scan six switches at each station (A-D), two adjacent reed switches such as (41, 42) passing the first and last three signals from the associated remote station to respective gates (134, 136) which are enabled by the combined pulses from coils (21-23) and (24-26) respectively.

公开(公告)号：DE2608575A1

公开(公告)日：1976-09-30

申请号：DE2608575

申请日：1976-03-02

Applicant: IBM

Inventor： ABRAMSON PAUL ,  APPEL ULRICH

IPC: H04J3/17 ,  H04B3/20 ,  H04J6/02 ,  H03K13/22

Abstract: A connection system for varied distance digital communication capable of handling telephone signals utilizes Voice Activity Compression (VAC) to effectively share a given number of digital transmission channels among a greater number of virtual telephone connections. The telephone signals are delta-modulated and demodulated in system connection stations. The VAC processing circuits with a small increment of decision logic provide echo suppression. Echo suppression is thereby rendered as a "value-added" service at a relatively small increment of station cost over the cost of VAC processing. Echo interference with original telephone signal activity in the send channels is reduced by digital control of gain in the demodulation stage. The system also provides connections without VAC handling subject to echo control.

公开(公告)号：CA893806A

公开(公告)日：1972-02-22

申请号：CA893806D

Applicant: IBM

Inventor： ABRAMSON PAUL ,  STILWELL GEORGE R JR

IPC: H04L27/30 ,  H04Q9/00

公开(公告)号：CA873545A

公开(公告)日：1971-06-15

申请号：CA873545D

Applicant: IBM

Inventor： ABRAMSON PAUL

公开(公告)号：CA777922A

公开(公告)日：1968-02-06

申请号：CA777922D

Applicant: IBM

Inventor： ABRAMSON PAUL ,  CHIN PAO HSIUNG

公开(公告)号：CA773738A

公开(公告)日：1967-12-12

申请号：CA773738D

Applicant: IBM

Inventor： STILWELL GEORGE R JR ,  ABRAMSON PAUL