Patents Examined by Kevim Kim
  • Patent number: 6535550
    Abstract: A transceiver includes a receive unit and a transmit unit. The receive unit is adapted to receive a prefix width parameter. The transmit unit includes a modulator and a cyclic prefix unit. The modulator is adapted to receive digital data and generate an output symbol based on the digital data. The output symbol includes a plurality of waveform samples. The cyclic prefix unit is adapted to receive the output symbol and the prefix width parameter. The cyclic prefix unit generate a cyclic prefix based on a subset of the plurality of waveform samples and prepends the cyclic prefix to the output symbol to generate a transmit symbol. The size of the subset is based on the prefix width parameter. A method for adjusting the symbol rate of a transceiver includes receiving a prefix width parameter and receiving digital data. An output symbol is generated based on the digital data. The output symbol includes a plurality of waveform samples.
    Type: Grant
    Filed: March 2, 1999
    Date of Patent: March 18, 2003
    Assignee: Legerity, Inc.
    Inventor: Terry L. Cole
  • Patent number: 5760345
    Abstract: An identifier-adding unit adds an identifier to sending tele-writing information to be sent from the first tele-wiring system to a second tele-writing system via telecommunication. The identifier is used to identify a document to be processed as a result of a tele-writing operation being specified. This causes a second picture displayed on the second tele-wiring system to be affected, if appropriate, according to the sending tele-writing information. The information corresponds to a first tele-writing operation for affecting a first picture displayed on the first tele-writing system. A document identifying unit identifies, using an identifier added to received tele-writing information sent from the second tele-writing system to the first tele-writing system, a corresponding document to be processed as a result of the tele-writing operation being specified.
    Type: Grant
    Filed: November 17, 1995
    Date of Patent: June 2, 1998
    Assignee: Ricoh Company, Ltd,
    Inventor: Kouji Oka
  • Patent number: 5757850
    Abstract: The invention provides a transmission bit rate discrimination method and apparatus wherein, when a base station in a mobile communication which makes use of spectrum spreading performs transmission at a variable bit rate using four different transmission bit rates and repetitively transmits transmission symbols of a low transmission bit rate, a mobile station detects a rate of repetitions of received symbols and discriminates the transmission bit rate of received data simply. A received symbol sequence for one frame is inputted to shifters for shifting the received symbol sequence by one, three and seven symbol distances, respectively, and a correlation calculator for calculating an auto-correlation. The outputs of the shifters are inputted to correlation calculators for calculating cross-correlations, and results of the correlation calculations are inputted to a comparator, by which they are compared with reference to a result of the auto-correlation calculation to discriminate the transmission bit rate.
    Type: Grant
    Filed: November 2, 1995
    Date of Patent: May 26, 1998
    Assignee: NEC Corporation
    Inventor: Tetsuya Takaki
  • Patent number: 5710797
    Abstract: A single transducer digital communication receiver is described which is capable of extracting the data bits of at least one desired signal in the presence of interfering signals of similar type. The present invention also seeks to provide a communication system in which overlapping transmissions are tolerated and allowed. The present invention describes a design for a digital communication system, according to a specific frequency plan, which includes an appropriate digital demodulator that extracts the data bits of the desired signal(s) in the presence of closely spaced signals. The present invention enables reduced channel spacing in digital communication systems and thereby increases the system capacity (i.e. the number of users per bandwidth unit) without incurring any significant loss in system performance (e.g. power margins, BER, and channel availability). It also allows a reduced power margin that is required to maintain a pre-specified performance level without sacrificing system capacity.
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: January 20, 1998
    Assignee: LIBIT Signal Processing Inc.
    Inventors: Mordechai Segal, Ofir Shalvi
  • Patent number: 5621756
    Abstract: The current invention is a method (100), super-regenerative transceiver (300), and computer system (500) for providing short range communication with reduced current drain. A control unit provides an amplifier "ON" pulse periodically to a radio frequency amplifier to allow reduced current drain. The radio frequency amplifier eliminates antenna effects in an input signal to provide an amplified input signal. The control unit also provides a receiver "ON" pulse to a super-regenerative receiver immediately following the amplifier "ON" pulse to allow reduced current drain. The super-regenerative receiver detects received data given the amplified input signal.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: April 15, 1997
    Assignee: Motorola, Inc.
    Inventors: Harry D. Bush, George N. Kotzamanis, James O. Tomaszewski
  • Patent number: 5604775
    Abstract: In a digital phase locked loop, a coarse stepsize variable delay line and a fine stepsize variable delay line are connected in series for receiving a reference clock pulse and imparting thereto variable delays in accordance with higher significant bits and lower significant bits. The delayed clock pulse is delivered to the input of a clock tree through which the clock pulse propagates and are supplied to various parts of an integrated circuit chip. A phase detector provides a phase comparison between the reference clock pulse and a delayed clock pulse appearing at one of the outputs of the clock tree. A delay controller counts the reference clock pulse to produce a count value, and increments or decrements the count value in accordance with the output of the phase detector.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: February 18, 1997
    Assignee: NEC Corporation
    Inventors: Tetsuo Saitoh, Syuji Matsuo, Itsurou Taniyoshi, Koichi Kitamura