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公开(公告)号：DE69535527D1
公开(公告)日：2007-08-16
申请号：DE69535527
申请日：1995-09-22
Applicant: IBM
Inventor： FLEEK ARTHUR E , CAMP WILLIAM O JR , WARCHOCKI GARY M , BRACCO MICHAEL J , YEAGER RALPH
IPC: H04L27/18 , H04L27/20 , H03D3/00 , H04L27/233
Abstract: The oscillator at the sending node of a wireless digital network, generates a carrier signal, starting at a first instant. A modulator coupled to the oscillator performs phase shift modulating of the carrier signal with an input signal. A spoiler signal generator is coupled to the modulator, for providing a spoiler signal as the input signal, starting at the first instant and continuing for a first duration which is longer than a period needed for the oscillator to achieve stable characteristics. A transmitter is coupled to the modulator at the sending node, for transmitting a wireless radio signal representation of the carrier signal phase shift modulated with the spoiler signal to a receiver at a receiving node. The spoiler signal in the modulated carrier signal interrupts the periodic characteristic of the pulses, and thereby prevents the carrier sensor from detecting the carrier signal. Further, the spoiler signal ceases to modulate the carrier signal after the first duration when the oscillator has achieved stable characteristics, thereby enabling the carrier sensor to detect the carrier signal.
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公开(公告)号：CA2153443C
公开(公告)日：2001-12-11
申请号：CA2153443
申请日：1995-07-07
Applicant: IBM
Inventor： FLEEK ARTHUR E , LAMAIRE RICHARD O
Abstract: A method for use in a single cell of a wireless communication system of the type having a leader station that coordinates communication among a plurality of remote st ations that are in the cell. The method applies to systems that use slow frequency-hopping r adios and a Carrier Sense Multiple Access (CSMA) type protocol. In this context, the met hod allows a remote station to initially acquire the frequency-hopping pattern and time b ase of the leader station and to maintain frequency synchronization in the face of control inf ormation loss due to radio transmission effects (e.g., interference, noise or multipath fading ). In the acquisition phase, the remote station actively generates probe messages that are sent to the leader station so as to rapidly achieve frequency synchronization with the leader station.
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公开(公告)号：AU7090981A
公开(公告)日：1982-11-25
申请号：AU7090981
申请日：1981-05-21
Applicant: IBM
Inventor： BOLCAVAGE RICHARD D , FLEEK ARTHUR E , MARCUS MITCHELL P
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公开(公告)号：DE69535527T2
公开(公告)日：2008-03-13
申请号：DE69535527
申请日：1995-09-22
Applicant: IBM
Inventor： FLEEK ARTHUR E , CAMP WILLIAM O JR , WARCHOCKI GARY M , BRACCO MICHAEL J , YEAGER RALPH
IPC: H04L27/18 , H04L27/20 , H03D3/00 , H04L27/233
Abstract: The oscillator at the sending node of a wireless digital network, generates a carrier signal, starting at a first instant. A modulator coupled to the oscillator performs phase shift modulating of the carrier signal with an input signal. A spoiler signal generator is coupled to the modulator, for providing a spoiler signal as the input signal, starting at the first instant and continuing for a first duration which is longer than a period needed for the oscillator to achieve stable characteristics. A transmitter is coupled to the modulator at the sending node, for transmitting a wireless radio signal representation of the carrier signal phase shift modulated with the spoiler signal to a receiver at a receiving node. The spoiler signal in the modulated carrier signal interrupts the periodic characteristic of the pulses, and thereby prevents the carrier sensor from detecting the carrier signal. Further, the spoiler signal ceases to modulate the carrier signal after the first duration when the oscillator has achieved stable characteristics, thereby enabling the carrier sensor to detect the carrier signal.
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公开(公告)号：DE69535030D1
公开(公告)日：2006-07-20
申请号：DE69535030
申请日：1995-09-22
Applicant: IBM
Inventor： FLEEK ARTHUR E , CAMP WILLIAM O , WARCHOCKI GARY M
IPC: G06F13/00 , H04L27/233 , H04L27/20
Abstract: A phase shift modulator at the transmitter has a control input connected to a binary signal source. A high frequency carrier signal is applied to a carrier signal input of the modulator. The modulated carrier signal is transmitted to a receiver where it is mixed with a local oscillator frequency. At the receiver, a modulated signal is amplified by a limit amplifier to form the received signal into square wave pulses of a uniform height. The demodulator detects when the spacing between the edges of the square wave signal change in response to the phase shift modulation at the transmitter. When the spacing between the edges of the square wave IF signal is detected to be shorter than the normal spacing for a steady IF signal with no modulation, this signifies a first binary value. A longer than normal spacing between the edges of the square wave IF signal signifies a second binary value. Frequency drift compensation circuits are disclosed to overcome frequency variations in the carrier and the local oscillator.
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Patent Agency Ranking
公开(公告)号：AU539298B2
公开(公告)日：1984-09-20
申请号：AU7090981
申请日：1981-05-21
Applicant: IBM
Inventor： BOLCAVAGE RICHARD D , FLEEK ARTHUR E , MARCUS MITCHELL P
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公开(公告)号：PL179099B1
公开(公告)日：2000-07-31
申请号：PL31667095
申请日：1995-09-08
Applicant: IBM
Inventor： FLEEK ARTHUR E , LAMAIRE RICHARD O
Abstract: A method for use in a single cell of a wireless communication system of the type having a leader station that coordinates communication among a plurality of remote stations that are in the cell. The method applies to systems that use slow frequency-hopping radios and a Carrier Sense Multiple Access (CSMA) type protocol. In this context, the method allows a remote station to initially acquire the frequency-hopping pattern and time base of the leader station and to maintain frequency synchronization in the face of control information loss due to radio transmission effects (e.g., interference, noise or multipath fading). In the acquisition phase, the remote station actively generates probe messages that are sent to the leader station so as to rapidly achieve frequency synchronization with the leader station.
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公开(公告)号：CA1186946A
公开(公告)日：1985-05-14
申请号：CA425599
申请日：1983-04-11
Applicant: IBM
Inventor： FLEEK ARTHUR E , TSENG SAMUEL C
Abstract: VARIABLE SPEED PRINTING FOR DOT MATRIX PRINTERS A variable speed printing (VSP) adaptor for a dot matrix printer which includes a monitoring means having a plurality of devices each capable of assuming one of two states. The monitoring means monitors the state of the pattern data to be printed, and, in the preferred embodiment, the monitoring means comprises a counter which is preset with a number equal to the number of column scans with a dot print line. The pattern data to be printed is scanned in a forward direction, i.e., in the normal printing direction starting at the first print position and the count in the counter is decremented one count for each column data scanned. During the time interval between when this data is latched and the actual hammer actuation, the pattern data is scanned in the backward direction starting at the last print position. Each time the column data for a backward scan is zero, i.e., no dot to be printed, prior to sensing a non-zero column, the count in the counter is decremented one count. The printing operation continues in the interleaved forward/backward scans until the count in the counter reaches a reference level such as zero. Upon sensing this reference level in the counter, a control signal is generated which indicates that the printing of the dot row is complete and initiates movement of the paper to the next dot row position. In an alternate embodiment, the monitoring means comprises a random access storage device.
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公开(公告)号：AU539581B2
公开(公告)日：1984-10-04
申请号：AU7090881
申请日：1981-05-21
Applicant: IBM
Inventor： BOLCAVAGE RICHARD D , FERRARO ARMAND J , FLEEK ARTHUR E
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公开(公告)号：CA1159710A
公开(公告)日：1984-01-03
申请号：CA365265
申请日：1980-11-21
Applicant: IBM
Inventor： BOLCAVAGE RICHARD D , FERRARO ARMAND J , FLEEK ARTHUR E
Abstract: A printer control system for a belt printer has an arrangement for checking print hammer operating circuits by comparing a real time actual parity of the circuits with a precalculated expected parity. Prior to printing, a microprocessor calculates expected parity bytes for each subscan for storage in a storage device along with the print position fire data used for selecting the operating circuits to be activated in the related subscans. An actual parity byte is generated on a real time basis by ODD/EVEN parity circuits associated with groups of operating circuits for comparison with a composite parity byte generated each subscan by the microprocessor. The composite parity byte is generated by combining the expected parity bytes from the storage device for several successive subscans. The composite parity byte is updated each subscan by a process of subtracting the initial expected parity byte and adding a new subscan expected parity byte. Comparison is made when all the activating circuits are in stable condition. EN979013
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