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公开(公告)号：JP2002237854A
公开(公告)日：2002-08-23
申请号：JP2001207789
申请日：2001-07-09
Applicant: IBM
Inventor： HIRT WALTER , GFELLER FRITZ
Abstract: PROBLEM TO BE SOLVED: To provide a method and device for achieving a reliable communication link by deciding the quality of a digital signal, preferably of an infrared signal. SOLUTION: In this device and method for deciding the quality of a digital signal s, n(n>=1) pieces of incoming digital signals S are sampled based on defined pulse width by using a clock cycle CLK. Then, an edge detector 20 detects the edge position of the pulse of the sampled digital signal, and a counter 30 counts clock cycles between at least the first edge and second edge detected by the edge detector. Then, a deviation detector 40 compares a counted clock cycle EEC with a stored reference value EEC0, and provides a deviation value RJ as the index of the instantaneous quality of the digital signal S. This deviation value RJ is supplied to a rework unit, and the rework unit supplies a value J as the index of the quality of the digital signal.
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2.发明专利
公开(公告)号：JP2002141873A
公开(公告)日：2002-05-17
申请号：JP2001207719
申请日：2001-07-09
Applicant: IBM
Inventor： GFELLER FRITZ , HIRT WALTER
Abstract: PROBLEM TO BE SOLVED: To provide a device and a method for determining the pulse position of a signal encoded by pulse modulation. SOLUTION: In the device and the method for determining pulse position of signal encoded by pulse modulation, a signal can be received as a first component PCS and a second component DCS at least. A first storage unit 102 stores one symbol of the first component PCS at least and a second storage unit 104 stores one symbol of the second component DCS at least. A determination unit 118 is provided with a probability table 110 and when receiving the first and second components PCS and DCS, the address of this table is designated by at least one symbol of the first component PCS and at least one symbol of the second component DCS. Thus, the probability table 110 provides a value to be defined as a pulse position DDS.
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3.发明申请TRANSPONDER SUBSYSTEM FOR SUPPORTING LOCATION AWARENESS IN WIRELESS NETWORKS 审中-公开用于支持无线网络中的位置感知的转发器子系统
公开(公告)号：WO2004017569A3
公开(公告)日：2004-07-15
申请号：PCT/IB0303703
申请日：2003-08-06
Applicant: IBM , GFELLER FRITZ , HIRT WALTER
Inventor： GFELLER FRITZ , HIRT WALTER
CPC classification number: H04W64/00 , G01C21/206 , G01S5/0252
Abstract: The present invention is related to an apparatus and method for determining the location of a communication device within a wireless network in order to provide a geolocation functionality to the communication device participating under an access protocol of a wireless local-area network (WLAN) infrastructure such as IEEE 802.11 or Hiperlan. The apparatus comprises at least two transponder units for communicating with the communication device when the communication device is situated in a coverage area of the wireless network and a processing unit for deriving the location of the communication device within the coverage area in dependence on information received from the transponder units.
Abstract translation: 本发明涉及用于确定无线网络内的通信设备的位置的设备和方法，以便为参与无线局域网（WLAN）基础设施的接入协议的通信设备提供地理定位功能性， 作为IEEE 802.11或Hiperlan。 该装置包括至少两个转发器单元，用于当通信设备位于无线网络的覆盖区域中时与通信设备进行通信，以及处理单元，用于根据从接收到的信息获得覆盖区域内的通信设备的位置 应答器单元。
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公开(公告)号：DE69425000D1
公开(公告)日：2000-07-27
申请号：DE69425000
申请日：1994-02-28
Applicant: IBM , IBM DEUTSCHLAND INFORMATIONSSY
Inventor： HIRT WALTER
Abstract: PCT No. PCT/EP94/00577 Sec. 371 Date Aug. 30, 1996 Sec. 102(e) Date Aug. 30, 1996 PCT Filed Feb. 28, 1994 PCT Pub. No. WO95/23461 PCT Pub. Date Aug. 31, 1995The wireless communication system, comprising a transmitter and a receiver, operates according to the present PPM-FSK modulation format with two subcarrier frequencies f1 and f2. The PPM encoded data on the main data channel 43 are fed to two pulse shaping circuits (30, 31) for additional frequency modulation with said frequencies. The resulting hybrid PPM-FSK signal is used to drive a light source (32). The receiver comprises a photodiode (34) coupled to an amplifier (35). The electrical signal obtained at the output of the amplifier (35) is fed to bandpass filters (36, 37) and envelope detectors (38, 39). The outputs of the envelope detectors are fed to a device (40) designed for pulse restoration and frequency decision. In a first operation, device (40) uses the output signals of the two envelope detectors (38, 39) to derive from them the estimated PPM encoded data signal. It then uses this signal to produce estimated restored pulses and outputs them. Then device (40) uses the output signals of the two envelope detectors to derive the estimated frequency information which carries auxiliary data information. It then uses this signal to produce estimated restored auxiliary data bits.
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公开(公告)号：DE69425000T2
公开(公告)日：2000-12-07
申请号：DE69425000
申请日：1994-02-28
Applicant: IBM , IBM DEUTSCHLAND INFORMATIONSSY
Inventor： HIRT WALTER
Abstract: PCT No. PCT/EP94/00577 Sec. 371 Date Aug. 30, 1996 Sec. 102(e) Date Aug. 30, 1996 PCT Filed Feb. 28, 1994 PCT Pub. No. WO95/23461 PCT Pub. Date Aug. 31, 1995The wireless communication system, comprising a transmitter and a receiver, operates according to the present PPM-FSK modulation format with two subcarrier frequencies f1 and f2. The PPM encoded data on the main data channel 43 are fed to two pulse shaping circuits (30, 31) for additional frequency modulation with said frequencies. The resulting hybrid PPM-FSK signal is used to drive a light source (32). The receiver comprises a photodiode (34) coupled to an amplifier (35). The electrical signal obtained at the output of the amplifier (35) is fed to bandpass filters (36, 37) and envelope detectors (38, 39). The outputs of the envelope detectors are fed to a device (40) designed for pulse restoration and frequency decision. In a first operation, device (40) uses the output signals of the two envelope detectors (38, 39) to derive from them the estimated PPM encoded data signal. It then uses this signal to produce estimated restored pulses and outputs them. Then device (40) uses the output signals of the two envelope detectors to derive the estimated frequency information which carries auxiliary data information. It then uses this signal to produce estimated restored auxiliary data bits.
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Patent Agency Ranking
公开(公告)号：AU2003255950A1
公开(公告)日：2004-03-03
申请号：AU2003255950
申请日：2003-08-06
Applicant: IBM
Inventor： HIRT WALTER , GFELLER FRITZ
Abstract: The present invention is related to an apparatus and method for determining the location of a communication device within a wireless network in order to provide a geolocation functionality to the communication device participating under an access protocol of a wireless local-area network (WLAN) infrastructure such as IEEE 802.11 or Hiperlan. The apparatus comprises at least two transponder units for communicating with the communication device when the communication device is situated in a coverage area of the wireless network and a processing unit for deriving the location of the communication device within the coverage area in dependence on information received from the transponder units.
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公开(公告)号：PL345465A1
公开(公告)日：2001-12-17
申请号：PL34546599
申请日：1999-07-01
Applicant: IBM
Inventor： HASSNER MARTIN AURELIANO , HEISE NYLES , HIRT WALTER , TRAGER BARRY MARSHALL
Abstract: A method and means for reducing high-duty-cycle unconstrained binary signal sequences in storage and communications processes and systems by invertibly mapping such sequences into a (1, k) rate ⅔ RLL codestream constrained to a duty cycle substantially approximating one-third. That is, binary sequences ordinarily mapping into high-duty-cycle RLL-code sequences are either inhibited from repeating indefinitely or excluded.
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公开(公告)号：ID27940A
公开(公告)日：2001-05-03
申请号：ID20002555
申请日：1999-07-01
Applicant: IBM
Inventor： HASSNER MARTIN AURELIANO , HEISE NYLES , TRAGER BARRY MARSHALL , HIRT WALTER
Abstract: A method and means for reducing high-duty-cycle unconstrained binary signal sequences in storage and communications processes and systems by invertibly mapping such sequences into a (1, k) rate ⅔ RLL codestream constrained to a duty cycle substantially approximating one-third. That is, binary sequences ordinarily mapping into high-duty-cycle RLL-code sequences are either inhibited from repeating indefinitely or excluded.
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9.发明专利
公开(公告)号：CZ9802040A3
公开(公告)日：1998-10-14
申请号：CZ204098
申请日：1996-01-03
Applicant: IBM
Inventor： DE LANGE MARTIN , GFELLER FRITZ RUDOLF , HIRT WALTER
IPC: H04B10/114 , H04L1/00 , H04L7/04 , H04L12/28 , H04B10/10
CPC classification number: H04L7/042 , H04B10/1141 , H04B10/1149 , H04L1/0003 , H04L1/0025 , H04L7/046 , Y02D50/10
Abstract: The communication system includes a robust physical layer header (RPLH) which can be understood by all participating stations. This robust header (50) at least comprises a preamble (52) consisting of frames forming a periodic sequence of pulses, the number of slots per frame and the frame content being known to all participating stations. The preamble serves for relative synchronization and carrier detection of the receiving stations. The robust header further comprises a unique synchronization word (53) which is used for absolute synchronization of the receiving stations. This synchronization word is followed by a control field (59) of fixed length and known structure. The control field informs the receiving stations of which modulation method will be used for the transmission of data. Pref. the control field also includes data for communication link and network control.
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10.发明专利
公开(公告)号：GB2286952A
公开(公告)日：1995-08-30
申请号：GB9503986
申请日：1995-02-28
Applicant: IBM
Inventor： COKER JONATHAN DARREL , DOLIVO FRANCOIS BERNARD , GALBRAITH RICHARD LEO , HERMANN RETO , HIRT WALTER , VANNORSDEL KEVIN
IPC: G11B20/10 , G11B20/18 , H03H15/00 , H03H17/00 , H03H21/00 , H03M13/23 , H04B3/04 , H04L25/497 , G11B20/14
Abstract: A method and apparatus are provided for maximum-likelihood data detection in a partial-response (PR) data channel including a head and disk assembly providing an analog signal coupled to an analog to digital converter (ADC) providing digital samples. A plurality of digital samples are received from the ADC. The received digital samples are applied to a selected first filter 402 and a selected second filter 404. The first filtered digital samples are applied to a first data detector 406, and the second filtered digital samples are applied to a second data detector 408. A predetermined parameter is identified 410, and at least one of the first and second data detectors is selected responsive to the identified predetermined parameter. The detectors may comprise partial response, adaptive, full-state or reduced-state Viterbi detectors (e.g. PR4 or EPR4 Viterbi detectors).
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