Patents by Inventor Sudhir Ramakrishna

Sudhir Ramakrishna has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20070091837
    Abstract: The present invention provides a method and an apparatus for wireless communication between a base station and at least two mobile stations in a cellular system. The method comprises sending on a forward link at least one of a first and a second command to the at least two mobile stations that the base station is serving on a reverse link. The method further comprises controlling a transmission in at least one of a first and a second transmission mode of at least one mobile station among the at least two mobile stations on the reverse link based on the at least one of the first and second commands. Each of at least two mobile stations may determine a change of transmission mode between an orthogonal or a non-orthogonal transmission mode on a reverse link based on a message on a forward link. A scheduler at a serving base station may match scheduling or transmission resources to the transmissions on the reverse link.
    Type: Application
    Filed: October 21, 2005
    Publication date: April 26, 2007
    Inventors: Shupeng Li, Sudhir Ramakrishna, Ashok Rudrapatna
  • Publication number: 20070091786
    Abstract: The present invention provides a method and an apparatus for a wireless communication between at least one mobile station and a base station in a cellular system. The method comprises providing a desired spreading in time and frequency domains to transmit data using at least two carriers in a transmission on an uplink to the base station. Either the base station may provide an indication to the mobile station to enable the desired spreading, or alternatively, the mobile station may request it. A spread-spectrum cellular system may enable a mobile station to provide a two-dimensional spreading, which distributes spreading in time and frequency directions. A single two-dimensional spreading code or at least two one-dimensional spreading codes may provide a two-dimensional spreading. In this way, in an uplink transmission using a multi-carrier, code division multiple access (MC-CDMA) protocol, by varying the data portions being spread in time and frequency domains a joint spreading may result.
    Type: Application
    Filed: October 21, 2005
    Publication date: April 26, 2007
    Inventors: Shupeng Li, Sudhir Ramakrishna, Ashok Rudrapatna
  • Publication number: 20070093262
    Abstract: The present invention provides a method and an apparatus for transmitting data on an uplink by selectively using multiple access modes to multiplex a transmission based on at least two different transmit formats. A method of wireless communication between at least one mobile station and a base station sector in a cellular system enables a first transmit format for a first transmission of the at least one mobile station on an uplink to the base station sector to multiplex first and second components of the first transmission based on a first access mode. The method further comprises enabling a second transmit format different than the first transmit format for a second transmission on the uplink from the at least one mobile station to multiplex first and second components of the second transmission based on a second access mode.
    Type: Application
    Filed: October 21, 2005
    Publication date: April 26, 2007
    Inventors: Shupeng Li, Sudhir Ramakrishna, Ashok Rudrapatna
  • Publication number: 20060274689
    Abstract: A method is provided for controlling communications between a base station and a mobile device. The method comprises transmitting dedicated rate control information to the mobile device within a common rate control communications system. For example, dedicated rate control information may be embedded in a data packet and delivered to the mobile device over a data channel. The mobile device may be configured to extract the embedded dedicated rate control information from the data packet and use the information to control aspects of its transmission, such as time slot and rate.
    Type: Application
    Filed: June 2, 2005
    Publication date: December 7, 2006
    Inventors: Shupeng Li, Sudhir Ramakrishna, Ashok Rudrapatna
  • Publication number: 20060274702
    Abstract: A method is provided for controlling communications between a base station and a mobile device. The method comprises transmitting a pilot signal having at least one transmitted characteristic over a channel. A data rate control signal is received, indicating a variation between the transmitted characteristic and a corresponding actual characteristic of the pilot signal received at a remote location. The data rate control signal is modified based on a coefficient related to the bandwidth of the channel, and a transmission rate is determined based on the modified data rate control signal.
    Type: Application
    Filed: June 3, 2005
    Publication date: December 7, 2006
    Inventors: Shupeng Li, Sudhir Ramakrishna, Ashok Rudrapatna
  • Publication number: 20060203793
    Abstract: A method is provided for controlling communications between a base station and a mobile device. The method comprises transmitting information between the base station and the mobile device over a plurality of sub-channels where each sub-channel has a different carrier frequency. A first portion of the sub-channels are used for legacy mobile devices, and a second portion of the sub-channels is used by new mobile devices.
    Type: Application
    Filed: March 9, 2005
    Publication date: September 14, 2006
    Inventors: Shupeng Li, Lawrence Ozarow, Sudhir Ramakrishna, Ashok Rudrapatna
  • Publication number: 20060199544
    Abstract: A method for exploiting the diversity of a multi-carrier cellular system's frequency bands, for purposes of increasing network capacity, involves a base station transmitting a pilot signal on each frequency band to a plurality of mobile stations. Each mobile station measures the SIR of each pilot signal on the frequency bands, and this information is transmitted back to the base station. The base station may be configured to utilize this information in a number of manners, all of which are intended to increase channel capacity. For example, on each frequency band, the base station may transmit data signals only to those mobiles stations with the best signal quality on that frequency band. Additionally, the base station may transmit signals to one or more mobile stations across one or more frequency bands simultaneously, with transmissions on each band being adapted to the corresponding channel conditions.
    Type: Application
    Filed: March 2, 2005
    Publication date: September 7, 2006
    Applicant: Lucent Technologies Inc.
    Inventors: Sudhir Ramakrishna, Ashok Rudrapatna
  • Publication number: 20060199577
    Abstract: A method enables the use of a secondary pilot signal and a secondary antenna(s) in the forward link of a CDMA-based cellular network employing a slotted transmission scheme with a time-multiplexed primary pilot signal, with backwards compatibility. The forward link is divided into a number of time slots. For communications with “legacy” mobile stations that expect transmissions from a single, primary antenna (and that expect a single, primary pilot signal), during some of the time slots, only the primary antenna is used for transmissions, including transmitting the primary pilot signal. Neither the secondary pilot channel nor any other signals from the secondary antenna are transmitted. During the remaining time slots: (i) the primary pilot signal is transmitted from the primary antenna, and the secondary pilot signal is transmitted from the secondary antenna, but at different times; and (ii) data meant for the legacy mobile stations is not transmitted.
    Type: Application
    Filed: March 2, 2005
    Publication date: September 7, 2006
    Applicant: Lucent Technologies Inc.
    Inventors: Sudhir Ramakrishna, Ashok Rudrapatna
  • Patent number: 7092731
    Abstract: The capacity of a reverse link is improved by realizing a scheme to effect sharp changes in pilot channel transmit power (PCTP) and data channel to pilot power ratio (DCPR), coordinated with the start of the data channel transmission. The change in pilot power and data channel to pilot power ratio is also applicable to mobiles that use multiple pilots and/or multiple antennas at the transmitter and/or receiver.
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: August 15, 2006
    Assignee: Lucent Technologies Inc.
    Inventors: Nandu Gopalakrishnan, Sudhir Ramakrishna, Ganapathy Subramanian Sundaram
  • Patent number: 6891852
    Abstract: A method to adjust the burst transmission duration time, in a high speed digital wireless communication system, to provide sufficient time for the transmission of data when all the data is not available at the time of transmission. According to the method of the invention, after the burst transmission is begun, the burst is maintained active as additional data is selected within a known time period following the previous detected data packet and the detected data is appended to the active burst transmission. The invention further terminates the burst duration when no additional data is detected within the redefined time period following the previous detected data packet.
    Type: Grant
    Filed: April 8, 1999
    Date of Patent: May 10, 2005
    Assignee: Lucent Technologies Inc.
    Inventors: Joseph E. Cloutier, Wen-Yi Kuo, Sudhir Ramakrishna
  • Publication number: 20040176124
    Abstract: An embodiment of the present invention provides a method for improving the capacity of a reverse link by realizing a scheme to effect sharp changes in pilot channel transmit power (PCTP) and data channel to pilot power ratio (DCPR), coordinated with the start of the data channel transmission. The change in pilot power and data channel to pilot power ratio is also applicable to mobiles that use multiple pilots and/or multiple antennas at the transmitter and/or receiver.
    Type: Application
    Filed: March 6, 2003
    Publication date: September 9, 2004
    Inventors: Nandu Gopalakrishnan, Sudhir Ramakrishna, Ganapathy Subramanian Sundaram
  • Patent number: 6453151
    Abstract: A method is described to reduce the time required to assign the burst transmission parameters in a wireless communication system by autonomously sharing transmission and reception information among the components of the network. Information is autonomously provided from a remote subnetwork element to a controlling network element so the controlling network element may use the information to dynamically assign and update burst transmission parameters.
    Type: Grant
    Filed: June 21, 1999
    Date of Patent: September 17, 2002
    Assignee: Lucent Technologies, Inc.
    Inventors: T. Roger Kiang, Tejaskumar R. Patel, Sudhir Ramakrishna