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    14.
    发明专利
    未知

    公开(公告)号：BR0100843A

    公开(公告)日：2001-10-30

    申请号：BR0100843

    申请日：2001-03-05

    Applicant: LUCENT TECHNOLOGIES INC

    Inventor： BHATOOLAUL DAVID LAHIRI ,  LIM SEAU SIAN ,  VENCESLASCHARRIERE PATRICK GEO ,  CAO QIANG

    IPC: H04J13/00 ,  H04B7/26 ,  H04J3/00 ,  H04M3/00 ,  H04W36/08 ,  H04W52/00 ,  H04W52/04 ,  H04W74/08 ,  H04Q7/32

    Abstract: When a mobile is switched on in a cellular system, it first searches for the best cell that it can connect to and then attempts to send a message to the best cell found. In CDMA cellular systems, the likelihood of a mobile's RACH message being successfully received by a cell is largely dependent on its transmit power. Unfortunately having all mobiles transmit at the maximum power possible is in many circumstances not only unnecessary but also unacceptable due to the resultant intra-cell interference generated. A cellular mobile telephone network is disclosed in which a mobile station requests service in data modulated on a common random access channel (RACH) in a format associated with first a cell in which the mobile station is located. Base stations in cells neighbouring the first cell, are configured to demodulate the RACH message burst having the format associated with the first cell, and to pass the demodulated data to a radio network controller (RNC). This enables the average power required for a successful RACH transmission to be reduced.

    15.
    发明专利
    未知

    公开(公告)号：BR0005403A

    公开(公告)日：2001-08-07

    申请号：BR0005403

    申请日：2000-11-16

    Applicant: LUCENT TECHNOLOGIES INC

    Inventor： BHATOOLAUL DAVID LAHIRI ,  CAO QIANG ,  CHARRIERE PATRICK ,  LIM SEAU SIAN

    IPC: H04L12/70 ,  H04L12/933 ,  H04Q11/04 ,  H04W28/02 ,  H04W88/18 ,  H04W92/04 ,  H04Q7/22

    Abstract: In a data packet, e.g. a PDU of the UMTS, a length indicator field (16) of variable granularity is created, depending on the exact length of the payload to be transmitted. An additional field (14) is provided, a single bit in length, to indicate the granularity of the length indicator field. This increases the resolution of the header, whilst keeping low an overhead of extra field bits. The method of the invention comprises: a. assessing (32, 34) the length of the data to determine the appropriate units, from a plurality of possible units, in which the length should be expressed; b. setting (36, 40) a granularity field to define said appropriate units in which the length of the data is to be indicated; and c. setting (38, 42) the length indicator field to indicate the data length.

    Preamble detector for a CDMA receiver
    16.
    发明专利
    Preamble detector for a CDMA receiver 未知

    公开(公告)号：AU7208800A

    公开(公告)日：2001-06-28

    申请号：AU7208800

    申请日：2000-12-07

    Applicant: LUCENT TECHNOLOGIES INC

    Inventor： BHATOOLAUL DAVID LAHIRI ,  MONOGIOUDIS PANTELIS

    IPC: H04B1/707 ,  H04B7/26 ,  H04J13/02 ,  H04B7/216 ,  H04L27/38

    Abstract: A receiver in a code-division, multiple-access (CDMA) communication system employs a preamble detector for random access channels (e.g., RACHs). RACHs may use orthogonal Gold code (OGC) sequences for preamble signature sequences and/or spreading of the preamble signature sequence with OGC sequences. A preamble detector may employ a fast orthogonal Gold transform (FOGT) for both despreading (e.g., correlation with code numbers C1,...,C256)) and for generating a decision statistic for detecting (identifying) the signature sequence used in the preamble. The spread signal of the RACH is applied to a code matched filter (CMF) matched to the spreading OGC sequence and the output signal of the CMF is sampled at the symbol rate. A fast Hadamaard transform (FHT) is applied to the sampled output of the CMF, and the exemplary 16th order code-words of the FHT match the 16 Walsh signature sequences employed to distinguish user channels transmitted by user equipment. A fast OGC transform (FOGT) may be applied to the sampled output of the CMF if OGC sequences are used as signature sequences. The signals generated by the FHT may be split into two branches for processing: a reference branch and a data branch. The reference branch processes the FHT generated signals to estimate channel response characteristics, provide a de-rotation signal, and perform frequency acquisition if required. For the reference branch, the squared magnitude of each complex FHT vector signal of length 16 is calculated and the maximum value is set as index i, where i ELEMENT ä1,.....16ü. The maximum index i is employed as a preliminary, non-coherent decision statistic corresponding to the index value of the Walsh signature sequence used for the spread signal of the access channel. The index i of the reference branch may then be used by: 1) a Walsh generator to reproduce the Walsh (BPSK) signature sequence; 2) a selector to select one of the 16 FHT output signals to estimate channel response characteristics; and 3) as a non-coherent decision statistic for subsequent processing by the detector.

    17.
    发明专利
    未知

    公开(公告)号：DE69936401T2

    公开(公告)日：2008-03-06

    申请号：DE69936401

    申请日：1999-12-10

    Applicant: LUCENT TECHNOLOGIES INC

    Inventor： BHATOOLAUL DAVID LAHIRI ,  LIM SEAU SIAN ,  CAO QIANG

    IPC: H04L29/08 ,  H04B7/005 ,  H04L1/16 ,  H04W28/04 ,  H04W52/48 ,  H04W52/50 ,  H04W74/08

    Abstract: In a UMTS, the AICH is arranged to send, in addition to a signal acknowledging that a preamble from a mobile is at an acceptable strength, an additional signal indicating that the mobile is not currently permitted to send its message; this may apply when the BTS does not have hardware resources available. If the BTS can predict when the hardware will become available, the additional signal can include a time out (T) after which the mobile system can send its message signal.

    Data packets for mobile telecommunications systems
    19.
    发明专利
    Data packets for mobile telecommunications systems 未知

    公开(公告)号：AU748635B2

    公开(公告)日：2002-06-06

    申请号：AU7166600

    申请日：2000-11-17

    Applicant: LUCENT TECHNOLOGIES INC

    Inventor： BHATOOLAUL DAVID LAHIRI ,  CAO QIANG ,  CHARRIERE PATRICK ,  LIM SEAU SIAN

    IPC: H04L12/70 ,  H04L12/933 ,  H04Q11/04 ,  H04W28/02 ,  H04W88/18 ,  H04W92/04 ,  H04L12/56 ,  H04Q7/32

    Abstract: In a data packet, e.g. a PDU of the UMTS, a length indicator field (16) of variable granularity is created, depending on the exact length of the payload to be transmitted. An additional field (14) is provided, a single bit in length, to indicate the granularity of the length indicator field. This increases the resolution of the header, whilst keeping low an overhead of extra field bits. The method of the invention comprises: a. assessing (32, 34) the length of the data to determine the appropriate units, from a plurality of possible units, in which the length should be expressed; b. setting (36, 40) a granularity field to define said appropriate units in which the length of the data is to be indicated; and c. setting (38, 42) the length indicator field to indicate the data length.

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