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    Providing real-time satellite television broadcasts to aircraft
    42.
    发明专利
    Providing real-time satellite television broadcasts to aircraft 未知

    公开(公告)号：GB2403876A

    公开(公告)日：2005-01-12

    申请号：GB0422662

    申请日：2000-12-21

    Applicant: INMARSAT LTD

    Inventor： TRACHTMAN EYAL ,  NEMES JOHNNY ,  CHEONG KEN

    IPC: H04N5/44 ,  H04B7/185 ,  H04H20/62 ,  H04H40/90 ,  H04N7/16 ,  H04N7/173 ,  H04N7/20 ,  H04H1/00

    Abstract: A system for providing real-time television broadcasts to aircraft via satellite 2 is described. The broadcast signal 11 is transmitted to the aircraft together with a communications signal 10, forming part of an existing communications network air interface. The system has a splitter 9 that separates the communications signal 10 from the broadcast signal 11 and enables the real-time broadcast to the displayed on-board the aircraft. The antenna 3 may be directional and have means 7 to steer the antenna 3 according to channel signal strength. A telecommunication terminal onboard the aircraft may be used as a broadcast control terminal to control a content of the broadcast channels via communication signals 18, 17.

    Multi-user detection and decoding
    43.
    发明专利
    Multi-user detection and decoding 未知

    公开(公告)号：GB2403103A

    公开(公告)日：2004-12-22

    申请号：GB0313903

    申请日：2003-06-16

    Applicant: INMARSAT LTD

    Inventor： GRANT ALEXANDER

    IPC: H04B1/707 ,  H04L1/00 ,  H03M13/45 ,  H04L27/38

    Abstract: An iterative multi-user detector and decoder includes a joint multi-user detector (DET) and separate soft demodulators (SDEM1-K), decoders (DEC1-K) and modulators (SM1-K) which provide updated estimates to the detector (DET) for the next iteration, through an estimated multi-user channel (EMA) which uses channel parameters estimated by a channel estimator (CE). The decoders (DEC1-K) use a weak decoding algorithm during initial iterations and a strong decoding algorithm during subsequent iterations of the detecting and decoding process, thereby avoiding convergence bottlenecks that would occur if strong decoding were used for all iterations.

    Wireless transceiver
    44.
    发明专利
    Wireless transceiver 未知

    公开(公告)号：AU2004202035A1

    公开(公告)日：2004-06-10

    申请号：AU2004202035

    申请日：2004-05-13

    Applicant: INMARSAT LTD

    Inventor： MUDGE DAVID DENIS ,  FEBVRE PAUL

    IPC: H04B7/15 ,  H04B7/185 ,  H04B7/212 ,  H04B7/26 ,  H04B7/005 ,  H04Q7/38

    Abstract: In a bandwidth allocation protocol for a mobile communications network, the network stores associations between forward and return frequency channels, so that when a mobile receiving a forward frequency channel request return capacity, the network preferentially assigns return bandwidth to the mobile in one or more of the associated return channels.

    46.
    发明专利
    未知

    公开(公告)号：DE69626213T2

    公开(公告)日：2003-11-27

    申请号：DE69626213

    申请日：1996-11-04

    Applicant: INMARSAT LTD

    Inventor： TRACHTMAN EYAL

    IPC: H04N1/00 ,  H04N1/32 ,  H04N1/333 ,  H04N1/41 ,  H04N1/411 ,  H04Q7/20

    Abstract: An image interface circuit for compressing an image for subsequent transmission via a radio transmission channel, comprising; an image reception port; an image reception circuit for receiving an image from said image reception port in a first compressed signal format; an image decompression circuit for decompressing said first compressed signal format; an image segmenting circuit for segmenting the image into text and non-text areas; an optical character recogniser for recognising text characters in the text areas and generating corresponding character data; an image encoder circuit for compression-encoding the non-text areas into a image data in a second image signal format different to said first image format; a compressed image transmission port connected to said radio transmission channel, and; a signal combiner circuit for combining the character data and the image data into a combined signal and supplying the combined signal to the compressed image transmission port.

    Channel Allocation and Assignment
    47.
    发明专利
    Channel Allocation and Assignment 未知

    公开(公告)号：GB2388747A

    公开(公告)日：2003-11-19

    申请号：GB0211031

    申请日：2002-05-14

    Applicant: INMARSAT LTD

    Inventor： RICHHARIA MADHAVENDRA ,  MUNDAY MARTIN ,  BATY CHARLTON

    IPC: H04B7/185 ,  H04L12/851 ,  H04Q7/38 ,  H04Q7/36

    Abstract: Satellite communications channels can be assigned as low priority and high priority channels, which are also called off peak and normal channels). The low priority channels may be appropriated (pre-empted) when high priority channels are unavailable for high priority calls. The number of high priority and low priority channels available throughout the day varies. A pool of available high priority channels is maintained whenever possible and therefore low priority channels may only be assigned when the pool of high priority channels is above a threshold size. The peak periods and off peak periods do not have to be determined in advance and therefore the system dynamically changes to suit current traffic levels.

    Carrier activation for data communications
    49.
    发明专利
    Carrier activation for data communications 未知

    公开(公告)号：GB2336508B

    公开(公告)日：2003-05-28

    申请号：GB9904575

    申请日：1999-02-26

    Applicant: INTERNAT MOBILE SATELLITE ORGA ,  INMARSAT TWO COMPANY ,  INMARSAT LTD

    Inventor： FELDMAN HOWARD RAY ,  WONG SIU WAH

    IPC: H04B7/185 ,  H04L12/28 ,  H04L29/06 ,  H04L29/08 ,  H04Q7/32

    Abstract: In a radio communications system in which data is transmitted on a modulated radio frequency carrier, the carrier is switched off when no data is available for transmission. If repeated signalling information is required to be transmitted, only a predetermined number of repeats are transmitted before the carrier is switched off. In one embodiment a bit sequence at the end of a first data block is compared with multiple sequences from a second block and if all sequences are equal, transmission of the second block is inhibited. In another embodiment data input for transmission is compared with a predetermined bit sequence. If a match is found for any relative bit alignment, this indicates an idle state (absence of user data) and the carrier is switched off. When more user data is received the carrier is switched on and frames are transmitted in synchronisation with the timing of frames transmitted before carrier deactivation. After carrier reactivation a constant power preamble may be transmitted to assist in level control in the transmitter. In a satellite SCPC system satellite power efficiency is improved and mobile earth station battery power is saved.

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