公开(公告)号：DE3783837D1

公开(公告)日：1993-03-11

申请号：DE3783837

申请日：1987-07-31

Applicant: IBM

Inventor： PEARCE HAROLD BRENT ,  WEST LYNN PARKER

IPC: H04L27/38 ,  H04L27/00 ,  H04L27/227

Abstract: A method and apparatus are described for phase and frequency locking a reference oscillator to an incoming modulated signal. The method and apparatus enable the carrier recovery of the incoming modulated signal. Phase and frequency locking devices are connected in feedback loops (20, 30) with a coherent detector (10) that determine the amount of phase and frequency error between the reference oscillator of the coherent detector and the incoming modulated signal. The feedback loops correct such frequency and phase error so as to enable the reference oscillator to be in phase and frequency step with the modulated signal.

公开(公告)号：BR8604618A

公开(公告)日：1987-05-26

申请号：BR8604618

申请日：1986-09-25

Applicant: IBM

Inventor： EINKAUF MARK ALAN ,  WEST LYNN PARKER

IPC: H04M1/60 ,  G10L11/00 ,  G10L11/02 ,  H04M1/65 ,  H04M3/42 ,  H04Q1/46 ,  H04B3/04

Abstract: This invention enables voice energy to be distinguished from energy due to other sources such as telephone call progress signals. A portion of the audio spectrum is divided into a high and into a low frequency band and the energy content of these bands is examined. The audio energy of a signal is passed through a set of filters and compared. A frequency boundary crossing of an input signal subsequent to filtering is used to signify the receipt of a voice signal. By operating in this manner, voice, whose predominant frequency switches in a random fashion from being greater than to less than a cutoff frequency, can be distinguished from other signals either below or above the cutoff frequencies of the filters. The detection of voice energy is not begun until a predetermined threshold of energy has been received for a specified period of time. This specified period of time need not be continuous after a ringback signal is received. Subsequent to the receipt of a ringback signal, the voice detection mechanism will proceed as long as the total time above the threshold exceeds the specified time.

公开(公告)号：DE2961825D1

公开(公告)日：1982-02-25

申请号：DE2961825

申请日：1979-07-16

Applicant: IBM

Inventor： ALVAREZ III JOSEPH ANTHONY ,  GOBIOFF BRUCE DEAN ,  WEST LYNN PARKER

IPC: H03M13/35 ,  H04B7/15 ,  H04B7/185 ,  H04B7/212 ,  H04J3/00 ,  H04L1/00 ,  H04L1/02 ,  G06F11/12 ,  H04J6/00 ,  H04L1/10

公开(公告)号：DE2339392A1

公开(公告)日：1974-03-21

申请号：DE2339392

申请日：1973-08-03

Applicant: IBM

Inventor： HAAS LEE CLYDE ,  WEST LYNN PARKER ,  LARSEN LARRY DONALD

IPC: G06F13/00 ,  H04L12/403 ,  H04L11/16

公开(公告)号：DE3789260D1

公开(公告)日：1994-04-14

申请号：DE3789260

申请日：1987-07-31

Applicant: IBM

Inventor： PEARCE HAROLD BRENT ,  WEST LYNN PARKER

IPC: H03G3/20 ,  H03G7/00

Abstract: Automatic gain control in a digital signal processor is described. An incoming electrical signal is sampled and multiplied by a gain factor with the resulting product compared to a constantly changing maximum value. If the magnitude of the changing maximum value lies outside a predetermined range of values, then the gain factor is adjusted proportionally to the error calculated by the amount the maximum value is outside the threshold range. In an alternative embodiment, the gain is adjusted according to whether or not one of the resulting products lies outside such upper and lower threshold range. The running maximum value decays with time in order to allow the automatic gain control to track a signal which slowly weakens in strength. A time dependent factor enables the gain to be adjusted much more radically when a signal is first received.

公开(公告)号：DE3377964D1

公开(公告)日：1988-10-13

申请号：DE3377964

申请日：1983-06-01

Applicant: IBM

Inventor： WEST LYNN PARKER

IPC: G06F15/173 ,  H04L12/00 ,  H04L12/26 ,  H04L11/00 ,  G06F13/00

Abstract: The present invention relates to a communication system including a plurality of terminals (31-35, 40-43), a plurality of processors (30, 40) and a digital switch (2). Switch (2) is designed to allow loop, star or multidrop network configurations to be set up each incorporating at least some of the terminals and one processor. A monitor (6) operates under control of a switch controller (5) to monitor any of the connections between the conductive elements (7, 8) of the switch.

公开(公告)号：BR8604619A

公开(公告)日：1987-05-26

申请号：BR8604619

申请日：1986-09-25

Applicant: IBM

Inventor： EINKAUF MARK ALAN ,  PARKER PAUL EDWARD ,  WEST LYNN PARKER ,  WILSON JOHN HAYDEN ,  HOEGH BRENT THOMAS ,  MCDONALD BRADLEY SCOTT

IPC: H04L29/10 ,  G06F13/00 ,  G06F13/38 ,  H04M11/00 ,  H04M11/06 ,  H04Q11/04

Abstract: A communication interface for providing asynchronous and telephonic communications is disclosed. The interface enables software applications, which are independent of any hardware or physical addresses, to operate on the interface. In this manner, the software applications can be written independent of hardware implementation and protocol implementation. A set of configuration parameters is defined for both an asynchronous and telephonic communication function set. Additionally, a set of interrupt conditions is defined for both the asynchronous and telephonic communication function sets. These parameters and interrupt conditions control the interaction of the software applications across the interface with the system hardware. Means are provided for directing commands coming from a software application across the interface to the system hardware. Likewise, means are provided for generating interrupts and handling these interrupts from the system hardware across the interface back to an interrupt routine within the software application.

公开(公告)号：DE2559003A1

公开(公告)日：1976-07-08

申请号：DE2559003

申请日：1975-12-29

Applicant: IBM

Inventor： PARKER BRIAN EUGENE ,  WEST LYNN PARKER

IPC: H04J3/00 ,  H04B7/15 ,  H04B7/185 ,  H04B7/212 ,  H04J3/24 ,  H04M3/00 ,  H04Q11/00 ,  H04Q11/04 ,  H04J6/02 ,  H04B7/14

Abstract: Modular digital exchange terminals linked in a network by earth satellite provide coordinated multiplex switching and activity compression between line circuits and satellite time division channels. The line circuits carry digital data and digitalized voice telephone information into and out of the network. Nodal access modules (NAU's) interface to the satellite radio equipment. Branch exchange modules (NCU's) link line circuits switchably to a nodal access module through time division channels of subsidiary digital communication links. In transit up-link (to satellite time division channels) information is switched between lines and NCU buffer stores (virtual channels), selectively assigned by activity compression to time channels on associated digital links (each link accommodating only a fraction of the virtual traffic capacity of the associated stores), and transmitted to the NAU. In the NAU the activity compressed composite is time-concentrated with traffic of other digital links (in NAU buffer storage), and passed out on demand assigned satellite time division (traffic burst) channels. In downlink distribution to outlet line circuits the receiving NAU picks out from the interleaved network composite only the information channels destined for its outlet line circuits. These are stored, reordered in space/time associations with digital link time channels and activity compressed into associated digital link channels. The receiving NCU buffers and switches the information through associated internal (virtual) channels to respective outlet line circuits (destinations).

公开(公告)号：DE2558980A1

公开(公告)日：1976-07-08

申请号：DE2558980

申请日：1975-12-29

Applicant: IBM

Inventor： BLASBALG HERMAN ,  MARKEY HAROLD G ,  RALEIGH N C ,  WEST LYNN PARKER

IPC: H04B7/185 ,  H04J3/17 ,  H04Q11/04 ,  H04B7/14 ,  H04J6/02

公开(公告)号：DE2558932A1

公开(公告)日：1976-07-08

申请号：DE2558932

申请日：1975-12-29

Applicant: IBM

Inventor： FLEMMING DONALD CLYDE ,  MARKEY HAROLD G ,  WEST LYNN PARKER ,  METZ RALPH J

IPC: H04J3/00 ,  H04B7/15 ,  H04B7/185 ,  H04B7/212 ,  H04J3/24 ,  H04M3/00 ,  H04Q11/00 ,  H04Q11/04 ,  H04J6/02 ,  H04B7/14

Abstract: Modular digital exchanges linked by earth satellite provide coordinated time division switching and time compressed communication services relative to externally attached telephone and data (user) trunks. Branch exchange modules (NCU's) perform call switching, buffer storage, time compression and activity selective channel assignment handling between individual external user trunks and multi-bit channels of external time division highways (digital links). The latter are linked pyramidally to time division multiple access nodes of the satellite through Network (Nodal) Access Unit modules (NAU's) which perform further time compression handling and adaptive assignment of satellite channels based upon nodal distribution of demand. The NCU modules also provide "local" switching between user trunks and "tandem" linkage directly between NCU's (without NAU and satellite handling). The modules have individual common control processors which inter-communicate via reserved signaling channels on the digital links and satellite. The modularity is in increments suitable for adaptive deployment of connection equipment relative to satellite access nodes (e.g. to adapt to shifts in user populations and/or plant facilities).