Patents by Inventor Subramanian Vasudevan

Subramanian Vasudevan 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).

  • Patent number: 7385944
    Abstract: In a method of canceling interference, a base station selects a known highest data rate user transmission from a received first signal containing a group of user transmissions. The known highest rate user transmission may be configured as one or more frames, each frame including a control preamble and a plurality of encoded sub-frames. The control preamble and encoded sub-frames may be decoded, and the decoded sub-frames may be used for removing interference caused by the known highest rate user transmission to all remaining transmissions of the group.
    Type: Grant
    Filed: March 31, 2003
    Date of Patent: June 10, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Hongwei Kong, Kumud K. Sanwal, Subramanian Vasudevan, Yunsong Yang, Henry Hui Ye, Jialin Zou
  • Patent number: 7352717
    Abstract: A method for performing network control in wireless communication systems and a network entity for performing the same. The method and network entity pool at least one network parameter at the network entity, from at least two active set base transceiver stations and determine a current status of a mobile in the wireless communication system, using the pooled network parameters. The active set base transceiver stations may include a serving base transceiver station and a target base transceiver station. The network parameter may be a confidence metric and/or an error metric for each of a plurality of hypotheses, a power up/power down signal, and/or a measured signal-to-noise ratio and/or energy parameter of a pilot signal from the mobile. The current status of the mobile to be determined may be the mobile's decision to switch to the target base transceiver station transceiver or which base transceiver station transceiver the mobile is currently communication with.
    Type: Grant
    Filed: May 31, 2002
    Date of Patent: April 1, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Douglas N. Knisely, David Albert Rossetti, Subramanian Vasudevan, Yunsong Yang
  • Publication number: 20080069027
    Abstract: A method and apparatus thereof for processing a composite signal by removing a plurality of multipaths of one or more stealth signals from the composite signal prior to decoding one or more user signals from the composite signal. The method and apparatus being operable to decode a stealth signal from the composite signal to produce a decoded stealth signal, to generate a regenerated stealth signal using the decoded stealth signal, and to subtract a plurality of multipaths of the stealth signal from the composite signal to produce a processed composite signal using the regenerated stealth signal. The stealth signal can be any user signal to be removed from the composite signal. Preferably, the stealth signal is a scheduled data transmission of a user associated with a high received power or data rate. The plurality of multipaths may be removed from the composite signal sequentially in order of descending signal strength.
    Type: Application
    Filed: September 20, 2006
    Publication date: March 20, 2008
    Inventors: Hongwei Kong, Subramanian Vasudevan
  • Publication number: 20080013476
    Abstract: A hybrid multi-mode mobile station makes a decision either to encode and modulate a new user data packet using the same OFDMA or pre-coded CDMA mode used for the last retransmission of a previous packet or to switch modes based on inputs of a measured average transmission power of the previous packet and a Signal-to-Interference plus Noise Ratio (SINR) as determined from measurements made by the base station and either directly reported to the mobile station or calculated by the mobile station from measurements made by the base station that are reported back to the mobile station.
    Type: Application
    Filed: July 13, 2006
    Publication date: January 17, 2008
    Inventor: Subramanian Vasudevan
  • Publication number: 20070298808
    Abstract: A wireless communication system is disclosed where a hub base station has an associated scheduler. Remotely located subscriber stations such as customer premises equipment devices each have their own associated scheduler in the vicinity of each device. The hub base station scheduler is responsible for scheduling communications in a first direction between the hub base station and the subscriber stations. Each subscriber station scheduler is responsible for scheduling communications in a second, opposite direction between the corresponding subscriber station and the hub base station. In one example, the schedulers associated with the subscriber stations are responsible for scheduling all backhaul or uplink communications from the subscriber station to the base station. A disclosed example is useful for WiMax communications.
    Type: Application
    Filed: June 27, 2006
    Publication date: December 27, 2007
    Inventors: Vic Pan, Subramanian Vasudevan
  • Publication number: 20070248051
    Abstract: A mobile terminal is controlled via over-the-air feedback so as to enable its data transmissions to be independently and successfully decoded at each of the base stations in its active set absent a transmit power limitation or data retransmission limit. Using the decoded data, the channel is re-estimated and the waveform received from the mobile terminal is reconstructed and subtracted from the total interference at each base station in the active set where decoding has been successful. As a result, transmissions from other mobile terminals, which have yet to be successfully decoded at such a base station, will experience a higher signal-to-noise ratio and thus an increased likelihood of being successfully decoded.
    Type: Application
    Filed: April 21, 2006
    Publication date: October 25, 2007
    Inventors: Shirish Nagaraj, Subramanian Vasudevan
  • Publication number: 20070248052
    Abstract: Successfully decoded data received from a mobile terminal as well as the transmission format of that data is relayed over the backhaul from a base station receiver that successfully decoded the mobile terminal's transmission to the base stations in the mobile terminal's active set that presumably were unable to decode the mobile terminal's transmission due to inadequate signal-to-noise ratio. A base station that receives this transmission from the relaying base station that did'successfully decode and demodulate the mobile terminal's transmission is then able to reconstruct the data and subtract it from the total interference, thereby increasing the signal-to-noise ratio at this base station for its in-cell processing.
    Type: Application
    Filed: April 21, 2006
    Publication date: October 25, 2007
    Inventors: Shirish Nagaraj, Subramanian Vasudevan
  • Publication number: 20070250726
    Abstract: An access terminal supports both a longer wakeup period and a shorter wakeup period (lower frequency of wakeups and higher frequency of wakeups, respectively) where the time interval over which the short wakeup period is active is prescheduled or enabled based on needs. Thus, when paging of the access terminal is expected to occur within a known interval of time, the access terminal enters a standby mode and is awoken more frequently during that interval.
    Type: Application
    Filed: April 24, 2006
    Publication date: October 25, 2007
    Inventors: David Rossetti, Subramanian Vasudevan, Jialin Zou
  • Publication number: 20070248032
    Abstract: The present invention provides a method for providing route update messages paging access terminals. The method may include providing at least one route update message based upon at least one travel pattern associated with an access terminal. The method may also include providing at least one page based on at least one previously received route update message and information indicative of at least one travel pattern.
    Type: Application
    Filed: April 21, 2006
    Publication date: October 25, 2007
    Inventors: Subramanian Vasudevan, Jialin Zou
  • Patent number: 7251228
    Abstract: A method for switching cells by a mobile equipment of a communication system. The mobile transmits a signal coded with a spreading code indicating the mobile's intent to switch cells and the coded information also identifies to which cell the mobile wants to switch. The coded information contains channel measurement adjustment information that is continuously transmitted to the cell which is currently serving the mobile. The flow of channel measurement adjustment information is therefore not disturbed by the application of the method of the present invention. Because the coded information identifies the target cell and indicates the mobile's intent to perform a cell switching procedure, the amount of processing done by the cells is significantly reduced thus increasing the likelihood of a successful switching procedure.
    Type: Grant
    Filed: March 5, 2002
    Date of Patent: July 31, 2007
    Assignee: Lucent Technologies Inc.
    Inventors: Douglas N. Knisely, Subramanian Vasudevan, Yunsong Yan, Wenfeng Zhang
  • Publication number: 20070173275
    Abstract: A closed loop power control based on receiving a continuous quality feedback is described. A main reverse link (RL) pilot is controlled by the quality feedback of a substantially continuous delay sensitive traffic stream, such as Voice-over-IP (VoIP), when such a stream is enabled. When such a stream is not enabled, the quality of a continuous RL overhead channel is used to control the pilot power. At the same time, the Traffic-to-Pilot Ratios (TPR) of contemporaneously transmitted delay sensitive data streams are independently adjusted based on a quality feedback associated with each such data stream.
    Type: Application
    Filed: January 13, 2006
    Publication date: July 26, 2007
    Inventors: Suman Das, Pantelis Monogioudis, Shirish Nagaraj, Subramanian Vasudevan, Harish Viswanathan, Jialin Zou
  • Publication number: 20070165667
    Abstract: A multiple mode data communication system and method provides the flexibility to schedule wireless unit transmissions and/or allow the wireless unit to transmit autonomously. In certain embodiments, the wireless units can transmit autonomously and/or use scheduling depending on the data rate, the length of the data packet or the type of data. For example, the wireless units can transmit autonomously at lower data rates and use scheduling at higher data rates. Thus, the multiple mode system enables wireless unit transmissions to be scheduled and/or be transmit autonomously, and wireless units can simultaneously operate in different scheduling and/or autonomous modes.
    Type: Application
    Filed: December 27, 2006
    Publication date: July 19, 2007
    Inventors: Srinivas Kadaba, Farooq Khan, Eshwar Pittampalli, Ashok Rudrapatna, Ganapathy Sundaram, Subramanian Vasudevan, Yunsong Yang
  • Publication number: 20070167183
    Abstract: A closed loop power control based on receiving a continuous quality feedback is described. A main reverse link (RL) pilot is controlled by the quality feedback of a substantially continuous delay-sensitive traffic stream, such as Voice-over-IP (VoIP), when such a stream is enabled. When such a stream is not enabled, the quality of a continuous RL overhead channel is used to control the pilot power. At the same time, the Traffic-to-Pilot Ratios (TPR) of contemporaneously transmitted delay-sensitive data streams are independently adjusted based on a quality feedback associated with each such data stream.
    Type: Application
    Filed: January 13, 2006
    Publication date: July 19, 2007
    Inventors: Subramanian Vasudevan, Jialin Zou
  • Publication number: 20070165857
    Abstract: A signaling method is provided that can improve the efficiency of forward-link control signaling in OFDM systems. The method involves using a set of forward-link subcarriers that are dedicated for control information, and are shared by a set of two or more users. The control information destined for each user is spread using a respective spreading code, thereby to provide a spread control message. The spread control messages destined for the various users are summed together prior to transmission.
    Type: Application
    Filed: January 13, 2006
    Publication date: July 19, 2007
    Inventors: Suman Das, Shirish Nagaraj, Subramanian Vasudevan, Harish Viswanathan
  • Publication number: 20070104133
    Abstract: In a frequency division duplex wireless communications system, the wireless network independently and separately assigns RL and FL carrier frequencies to a mobile station, thereby supporting a variable duplex frequency separation. The assigned RL and FL carrier frequencies can be within the same frequency segment, in different frequency segments within a band class, or can be in different band classes. This feature is supported by new channel mapping and signaling.
    Type: Application
    Filed: November 10, 2005
    Publication date: May 10, 2007
    Inventors: Jim Chao, Subramanian Vasudevan, Jialin Zou
  • Publication number: 20070066336
    Abstract: There is provided a method and apparatus for reducing packet assistant channel power usage in a wireless telephone system. More specifically, there is provided a method comprising measuring a power usage for a packet assistant channel, determining whether the power usage is above a threshold, and discontinuing transmission over the packet assistant channel for a period of time if the power usage is above the threshold.
    Type: Application
    Filed: September 19, 2005
    Publication date: March 22, 2007
    Inventors: Lawrence Merboth, Subramanian Vasudevan, Stanley Vitebsky, Henry Ye, Lily Zhu
  • Patent number: 7158504
    Abstract: A multiple mode data communication system and method provides the flexibility to schedule wireless unit transmissions and/or allow the wireless unit to transmit autonomously. In certain embodiments, the wireless units can transmit autonomously and/or use scheduling depending on the data rate, the length of the data packet or the type of data. For example, the wireless units can transmit autonomously at lower data rates and use scheduling at higher data rates. Thus, the multiple mode system enables wireless unit transmissions to be scheduled and/or be transmit autonomously, and wireless units can simultaneously operate in different scheduling and/or autonomous modes.
    Type: Grant
    Filed: May 21, 2001
    Date of Patent: January 2, 2007
    Assignee: Lucent Technologies, Inc.
    Inventors: Srinivas R. Kadaba, Farooq Ullah Khan, Eshwar Pittampalli, Ashok N. Rudrapatna, Ganapathy Subramanian Sundaram, Subramanian Vasudevan, Yunsong Yang
  • Publication number: 20060166673
    Abstract: The present invention provides a method and an apparatus for controlling a wireless transmission in a handoff zone. The method includes receiving a schedule grant selectively from a first base station sector of a multiplicity of base station sectors in an active set of a mobile station and receiving a rate control command concurrently at the mobile station from a second base station sector of the active set that did not provide said schedule grant to determine at least one of a rate level and a power level based on a precedence given to the schedule grant over the rate control command. Using a combining rule depending upon a particular case, the mobile station may resolve a rate or a power level for a protocol in a digital cellular network of a mobile communication system. For a first case, a first combining rule combines one or more rate control commands with one or more schedule grants for a common rate control protocol, adding a grant precedence parameter, i.e.
    Type: Application
    Filed: January 21, 2005
    Publication date: July 27, 2006
    Inventor: Subramanian Vasudevan
  • Publication number: 20060056354
    Abstract: A method for transmitting control information from multiple base stations in an active set to a mobile device in a wireless communication system reduces resource consumption by routing information originating from a plurality of active base stations through a single serving base station. The serving base station pools and resolves the information from the active base stations and sends the resolution of the pooled information over a downlink control channel for evaluation and response by the mobile device.
    Type: Application
    Filed: September 15, 2004
    Publication date: March 16, 2006
    Inventors: Subramanian Vasudevan, Yunsong Yang
  • Publication number: 20060039282
    Abstract: A method is provided for controlling a traffic-to-pilot ratio (TPR) in a wireless telecommunications channel. The methodology takes advantage of a preexisting feedback process used in hybrid ARQ transmission systems. Generally, information is transmitted over the communications channel, and then the acknowledgement (ACK) signal, or negative acknowledgements (NACK) signal, is used to adjust the TPR. The TPR is adjusted up substantially in response to receiving a NACK signal, and adjusted slightly down in response to receiving an ACK signal. In this manner, the TPR is rapidly adjusted up when a transmission fails, and is allowed to drift slowly down when a transmission succeeds.
    Type: Application
    Filed: August 23, 2004
    Publication date: February 23, 2006
    Inventors: Subramanian Vasudevan, Lily Zhu, Jialin Zou