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27 records (took 0.024 seconds)

    22.
    发明专利
    未知

    公开(公告)号：DE69934284D1

    公开(公告)日：2007-01-18

    申请号：DE69934284

    申请日：1999-08-23

    Applicant: LUCENT TECHNOLOGIES INC

    Inventor： HOFFBECK JOSEPH P ,  MEYERS MARTIN HOWARD ,  PREMJI AL-NASIR A ,  TARRAF AHMED A ,  TRACY KEVIN G

    IPC: H04B7/26 ,  G10L19/00 ,  H04B1/04 ,  H04L1/00 ,  H04Q7/36

    Abstract: It has been recognized that in a wireless communication system certain frames of encoded speech data transmitted between a base station and a mobile unit, or between a mobile unit and a base station, are more critical than others. A frame may be determined to be erased by the receiving base station or mobile unit due to noise or interference over the wireless transmission medium. If an erased frame cannot be recreated from one or more preceding frames, then it is more critical than a frame that can be recreated by an extrapolation of data from one or more preceding frames. Accordingly, on a frame-by-frame basis, each frame in a sequence of frames is identified as being critical or non-critical. Each frame that is identified as being critical is then transmitted in a manner that is more robust than the manner in which non-critical frames are transmitted to decrease the likelihood that a receiver will determine that the frame is erased. In a CDMA system, a current frame is identified as being critical by forming a weighted sum of the differences between corresponding frame parameters that represent the current frame and frame parameters that represent a previous frame. That weighted sum is compared with a threshold. If the weighted sum exceeds the threshold, then the current frame is classified as being a critical frame and is transmitted at a higher output level than non-critical frames are transmitted.

    23.
    发明专利
    未知

    公开(公告)号：BR9904473A

    公开(公告)日：2000-09-19

    申请号：BR9904473

    申请日：1999-08-19

    Applicant: LUCENT TECHNOLOGIES INC

    Inventor： TARRAF AHMED A

    IPC: H04L17/00 ,  H04L17/02 ,  H04L29/06 ,  H04L29/08 ,  H04M11/06 ,  H04W28/04 ,  H04Q7/20

    Abstract: An apparatus and method for conveying teletype signals over a wireless telecommunication system. When the apparatus receives a teletype signal, it derives information carried by said signal and represents said information as at least one message. The at least one message and/or the teletype signal is transmitted over the wireless telecommunication system. When the apparatus receives a signal from the wireless telecommunication system that it determines to be a teletype signal, the apparatus of the present invention decodes the teletype information from part of the received signal determined as not having been adversely affected by the telecommunication system.

    METHOD AND APPARATUS FOR IMPROVING THE QUALITY OF SPEECH SIGNALS TRANSMITTED OVER WIRELESS COMMUNICATION FACILITIES
    24.
    发明专利
    METHOD AND APPARATUS FOR IMPROVING THE QUALITY OF SPEECH SIGNALS TRANSMITTED OVER WIRELESS COMMUNICATION FACILITIES 未知

    公开(公告)号：CA2279124A1

    公开(公告)日：2000-03-03

    申请号：CA2279124

    申请日：1999-07-29

    Applicant: LUCENT TECHNOLOGIES INC

    Inventor： MEYERS MARTIN HOWARD ,  HOFFBECK JOSEPH P ,  PREMJI AL-NASIR A ,  TARRAF AHMED A ,  TRACY KEVIN G

    IPC: H04B1/04 ,  H04B7/26 ,  H04Q7/36 ,  H04L1/00 ,  H04Q7/22

    Abstract: It has been recognized that in a wireless communication system certain frames of encoded speech data transmitted between a base station and a mobile unit, or between a mobile unit and a base station, are more critical than others. A frame may be determined to be erased by the receiving base station or mobile unit due to noise or interference over the wireless transmission medium. If an erased frame cannot be recreated from one or more preceding frames, then it is more critical than a frame that can be recreated by an extrapolation of data from one or more preceding frames. Accordingly, on a frame-by-frame basis, each frame in a sequence of frames is identified as being critical or non-critical. Each frame that is identified as being critical is then transmitted in a manner that is more robust than the manner in which non-critical frames are transmitted to decrease the likelihood that a receiver will determine that the frame is erased. In a CDMA system, a current frame is identified as being critical by forming a weighted sum of the differences between corresponding frame parameters that represent the current frame and frame parameters that represent a previous frame. That weighted sum is compared with a threshold. If the weighted sum exceeds the threshold, then the current frame is classified as being a critical frame and is transmitted at a higher output level than non-critical frames are transmitted.

    APPARATUS AND METHOD FOR CONVEYING TTY SIGNALS OVER WIRELESS TELECOMMUNICATION SYSTEMS
    25.
    发明专利
    APPARATUS AND METHOD FOR CONVEYING TTY SIGNALS OVER WIRELESS TELECOMMUNICATION SYSTEMS 未知

    公开(公告)号：CA2278113A1

    公开(公告)日：2000-02-28

    申请号：CA2278113

    申请日：1999-07-21

    Applicant: LUCENT TECHNOLOGIES INC

    Inventor： TARRAF AHMED A

    IPC: H04L17/00 ,  H04L17/02 ,  H04L29/06 ,  H04L29/08 ,  H04M11/06 ,  H04W28/04 ,  H04L12/58

    Abstract: An apparatus and method for conveying teletype signals over a wireless telecommunication system. When the apparatus receives a teletype signal, it derives information carried by said signal and represents said information as at least one message. The at least one message and/or the teletype signal is transmitted over the wireless telecommunication system. When the apparatus receives a signal from the wireless telecommunication system that it determines to be a teletype signal, the apparatus of the present invention decodes the teletype information from part of the received signal determined as not having been adversely affected by the telecommunication system. FIG. 2.

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