Patents Examined by James Ewart
  • Patent number: 6556552
    Abstract: In CDMA mobile communication systems, there are cases in which communications are interrupted with the local base station while the mobile station is searching for channels other than the communication channel. A method is offered of preventing loss of information due to interruptions in such a case. There are a first transmission step for transmitting signals from the mobile station to the base station at a transmission rate R1 and a transmission output level P1 (when the transmission output is p in FIG. 10C), a suspension step of suspending signal transmissions from the mobile station to the base station (when no transmission output power as shown in the same drawing), and a second transmission step of transmitting signals from the mobile station to the base station at a transmission rate R2 higher than the transmission rate R1 and a transmission output level P2 higher than the transmission output level P1 (when 2p in the same drawing).
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: April 29, 2003
    Assignee: NTT Communications Networks, Inc.
    Inventors: Hisashi Nakagomi, Tadao Takami, Akihiro Higashi, Kiyohito Nagata
  • Patent number: 6539234
    Abstract: A first reception power measuring section 206 measures reception power of individual channel signals transmitted with a narrow directivity, and a second reception power measuring section 207 measures reception power of common channel signals transmitted with a wide directivity. A determining section 210 determines the presence or absence of a directional shift based on an average reception power of the individual channel signals and an average reception power of the common channel signals. A transmission power controlling means 211 performs transmission power control based on the determination result. This makes it possible to correctly determine the cause of a reduction in reception power and to control transmission power accurately.
    Type: Grant
    Filed: April 21, 2000
    Date of Patent: March 25, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Katsuhiko Hiramatsu, Kazuyuki Miya
  • Patent number: 6516185
    Abstract: A direct conversion type transceiver system incorporates an offset correction and automatic gain control system. The automatic gain control system includes an amplifier amplifying a baseband signal which is directly converted from a received incoming RF signal, a feedback offset canceller controllably canceling DC offset, an automatic gain controller controlling gain of the amplifier, and a feed forward offset canceller coupled to a signal peak detector. The signal peak detector controlling the automatic gain controller and the feed forward offset canceller simultaneously, the feed forward offset canceller further canceling the DC offset.
    Type: Grant
    Filed: May 24, 2000
    Date of Patent: February 4, 2003
    Assignee: Level One Communications, Inc.
    Inventor: Donald E. MacNally
  • Patent number: 6510144
    Abstract: In a router or packet processing node supporting Mobile IP, a method for causing packets to be retransmitted from a sender to a mobile node is disclosed. A plurality of packets having associated update information are received. The packets are intended for the mobile node. The update information associated with at least one of the received packets is stored. When the mobile node is disconnected from the sender and reconnects to the sender, without waiting for a timeout the sender is directed to retransmit a last portion of packets to the mobile node based on the stored update information. Apparatus and computer readable medium embodiments are also disclosed.
    Type: Grant
    Filed: December 7, 1999
    Date of Patent: January 21, 2003
    Assignee: Cisco Technology, Inc.
    Inventors: Gopal K. Dommety, Kent K. Leung, Roy Laurens
  • Patent number: 6507731
    Abstract: An amplifier having a linear operation region and a nonlinear operation region amplifies a transmission signal. A linear compensation circuit compensates the amplifier for linearity when operating in the nonlinear operation region. The operation of the linear compensation circuit is controlled so as to substantially bring the linear compensation operation to a stop when the amplifier operates in the linear operation region.
    Type: Grant
    Filed: November 24, 1999
    Date of Patent: January 14, 2003
    Assignee: NEC Corporation
    Inventor: Osamu Hasegawa