Patents by Inventor Eduardo A. S. Esteves

Eduardo A. S. Esteves 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: 7440431
    Abstract: A method and an apparatus for adaptive data rate selection in a high data rate (HDR) communication system are disclosed. An exemplary HDR communication system defines a set of data rates, at which an access point (AP) may transmit data packets to an access terminal (AT). The transmission data rate is selected to maintain target packet error rate (PER). Each AT monitors signal quality metric of signals received from APs. An AT receiving forward link signals from multiple ATs identifies the AT associated with the highest quality forward link signal.
    Type: Grant
    Filed: April 28, 2004
    Date of Patent: October 21, 2008
    Assignee: QUALCOMM Incorporated
    Inventors: Nagabhushana T. Sindhushayana, Eduardo A. S. Esteves, Rashid A. Attar, Qiang Wu
  • Patent number: 7417957
    Abstract: A method and an apparatus for rate control in a high data rate (HDR) communication system are disclosed. An exemplary HDR communication system defines a set of data rates, at which an access point (AP) may send data packets to an access terminal (AT). The data rate is selected to maintain targeted packet error rate (PER). The AT's open loop algorithm measures received signal to interference and noise ratio (SINR) at regular intervals, and uses the information to predict an average SINR over the next packet duration. The AT's closed loop algorithm measures a packet error rate (PER) of the received signal, and uses the PER to calculate a closed loop correction factor. The loop correction factor is added to the SINR value predicted by the open loop, resulting in an adjusted SINR.
    Type: Grant
    Filed: March 24, 2004
    Date of Patent: August 26, 2008
    Assignee: QUALCOMM Incorporated
    Inventors: Nagabhushana T. Sindhushayana, Rashid A. Attar, Eduardo A. S. Esteves
  • Patent number: 7245594
    Abstract: In a high data rate communication system capable of variable rate transmission, an open loop rate control can be adjusted with a closed loop rate control to maximize throughput. An access point generates interleaved multi-slot packets that allow an access terminal to transmit indicator messages to the access point in accordance with recently received data carried within slots of the multi-slot packets.
    Type: Grant
    Filed: May 12, 2000
    Date of Patent: July 17, 2007
    Assignee: Qualcomm Incorporated
    Inventors: Eduardo A. S. Esteves, Rashid A. Attar, Nagabhushana T. Sindhushayana
  • Patent number: 7239847
    Abstract: Methods and apparatus for selecting a serving sector in a high rate data (HDR) communication system are disclosed. An exemplary HDR communication system defines a set of data rates, at which a sector of an Access Point may send data packets to an Access Terminal. The sector is selected by the Access Terminal to achieve the highest data throughput while maintaining a targeted packet error rate. The Access Terminal employs various methods to evaluate quality metrics of forward and reverse links from and to different sectors, and uses the quality metrics to select the sector to send data packets to the Access Terminal.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: July 3, 2007
    Assignee: QUALCOMM Incorporated
    Inventors: Rashid A. Attar, Rajiv Vijayan, Roberto Padovani, Nagabhushana T. Sindhushayana, Qiang Wu, Peter J. Black, Eduardo A. S. Esteves
  • Patent number: 7228148
    Abstract: A method and apparatus that determines how much power to allocate to each of a plurality of reverse link power control (RLPC) Channels to be transmitted from a base station, based upon data rate control (DRC) messages transmitted to the base station. Historical information is used to determine the quality of the Forward Link over which the RLPC is to be transmitted. If the history of the DRCs received indicates that the remote station to which the RLPC Channel is to be directed has not transmitted a DRC recently, then the base station allocates power to the RLPC Channels based upon information provided to the base station in DRCs that were received by the base station, but that were directed to other base stations. Accordingly, the base station can allocate power among the RLPC Channels without having received explicit information as to the quality of the Forward Link between the base station and every remote station intended to receive the information on the RLPC Channels.
    Type: Grant
    Filed: October 6, 2003
    Date of Patent: June 5, 2007
    Assignee: QUALCOMM Incorporated
    Inventors: Eduardo A. S. Esteves, Peter J. Black
  • Patent number: 7177648
    Abstract: Methods and apparatus for selecting a serving sector in a high rate data (HDR) communication system are disclosed. An exemplary HDR communication system defines a set of data rates, at which a sector of an Access Point may send data packets to an Access Terminal. The sector is selected by the Access Terminal to achieve the highest data throughput while maintaining a targeted packet error rate. The Access Terminal employs various methods to evaluate quality metrics of forward and reverse links from and to different sectors, and uses the quality metrics to select the sector to send data packets to the Access Terminal.
    Type: Grant
    Filed: December 5, 2003
    Date of Patent: February 13, 2007
    Assignee: Qualcomm Incorporated
    Inventors: Rashid A. Attar, Rajiv Vijayan, Roberto Padovani, Nagabhushana T. Sindhushayana, Qiang Wu, Peter J. Black, Eduardo A. S. Esteves
  • Patent number: 7127654
    Abstract: A method and an apparatus for quick retransmission of signals in a communication system are disclosed. A transmitting terminal, e.g., a base station, transmits signals in a form of packets to a receiving terminal, e.g., a subscriber station. The receiving terminal determines if the packet was intended for the receiving terminal, and if so, the receiving terminal demodulates the packet. The receiving terminal then computes a quality metric of the packet, and compares the computed quality metric with a quality metric contained in the packet. If the quality metrics match, the packet is declared correctly received, and is forwarded for further processing. If the quality metrics fail to match, the receiving terminal sends a request for retransmission of the packet. The transmitting terminal determines which packet needs to be retransmitted based on the request for retransmission. The transmitting terminal then schedules the packet for retransmission.
    Type: Grant
    Filed: November 12, 2003
    Date of Patent: October 24, 2006
    Assignee: Qualcomm, Inc.
    Inventors: Ahmad Jalali, Eduardo A. S. Esteves, Nagabhushana T. Sindhushayana, Peter J. Black, Rashid A. Attar
  • Patent number: 7088701
    Abstract: In a high data rate communication system, a method and apparatus for improved throughput while transmitting data packets within multiple time slots. In order to avoid unnecessary retransmissions of a packet, a subscriber station sends a Stop-Repeat signal to a base station, causing the base station to cease further transmissions of the packet. In order to enable successful decoding of a packet, a subscriber station sends a Continue-Repeat signal to a base station, causing the base station to send retransmissions of the packet during time slots beyond a predetermined default number of time slots.
    Type: Grant
    Filed: April 14, 2000
    Date of Patent: August 8, 2006
    Assignee: Qualcomm, Inc.
    Inventors: Rashid Attar, Roberto Padovani, Peter J. Black, Nagabhushana T. Sindhushayana, Eduardo A. S. Esteves, Mehmet Gurelli
  • Patent number: 6975671
    Abstract: A system for providing an accurate interference value signal received over a channel and transmitted by an external transceiver. The system includes a first receiver section for receiving the signal, which has a desired signal component and an interference component. A signal extracting circuit extracts an estimate of the desired signal component from the received signal. A noise estimation circuit provides the accurate interference value based on the estimate of the desired signal component and the received signal. A look-up table transforms the accurate noise and/or interference value to a normalization factor. A carrier signal-to interference ratio circuit employs the normalization factor and the received signal to compute an accurate carrier signal-to-interference ratio estimate. Path-combining circuitry generates optimal path-combining weights based on the received signal and the normalization factor.
    Type: Grant
    Filed: October 8, 2003
    Date of Patent: December 13, 2005
    Assignee: Qualcomm Incorporated
    Inventors: Nagabhushana T. Sindhushayana, Eduardo A. S. Esteves
  • Patent number: 6975669
    Abstract: An efficient telecommunications receiver system for accurately decoding a received composite signal having a data signal component and a pilot signal component includes a first circuit for receiving the composite signal and extracting a pilot signal and a data signal from received composite signal. A second circuit calculates a log-likelihood ratio as a function of a channel estimate based on the pilot signal. A third circuit scales the log-likelihood ratio by a predetermined log-likelihood ratio scaling factor and provides an accurate log-likelihood value in response thereto. A fourth circuit decodes the received composite signal based on the accurate log-likelihood value and the data signal. The third circuit includes a carrier signal-to-interference ratio circuit for computing a first signal-to-interference ratio and a second signal-to-interference ratio based partly on the pilot signal.
    Type: Grant
    Filed: January 15, 2002
    Date of Patent: December 13, 2005
    Assignee: Qualcomm, Incorporated
    Inventors: Fuyun Ling, Nagabhushana T. Sindhushayana, Eduardo A. S. Esteves
  • Patent number: 6850499
    Abstract: In a data communication system capable of variable rate transmission, the data rate is determined by the largest C/I measurement of the forward link signals as measured at the Access Terminal. In one embodiment, the data transmission is scheduled based on an Access Terminal initiated forward power control, which reduces forward link rate quantization loss due to excess transmit power. The Access Terminal reports to the Access Point the excess C/I estimate for the selected rate. The Access Point then reduces its transmit power by an appropriate amount when serving that Access Terminal. In another embodiment, the data transmission is scheduled based on an Access Point initiated forward power control. The Access Point varies its transmit power over time either randomly or in synchronism with neighboring Access Points in the communication system, which enables an increase in the throughput achieved by users that receive a significant amount of interference.
    Type: Grant
    Filed: January 5, 2001
    Date of Patent: February 1, 2005
    Assignee: QUALCOMM Incorporated
    Inventors: Charles E. Wheatley, III, Rashid A. Attar, Eduardo A. S. Esteves
  • Publication number: 20040258035
    Abstract: A method and an apparatus of dynamically setting a rise-over-thermal (ROT) threshold to control user-to-user interferences in a wireless communication system are disclosed. The ROT threshold is set by determining whether an outage of communication has occurred, increasing the ROT threshold by a predetermined increment if the outage has not occurred, and decreasing the ROT threshold by a predetermined decrement if the outage has occurred.
    Type: Application
    Filed: June 19, 2003
    Publication date: December 23, 2004
    Inventors: Mingxi Fan, Eduardo A.S. Esteves, Rashid Ahmed Attar, Naga Bhushan, Peter J. Black
  • Publication number: 20040233867
    Abstract: In a data communication system capable of variable rate transmission, the data rate is determined by the largest C/I measurement of the forward link signals as measured at the Access Terminal. In one embodiment, the data transmission is scheduled based on an Access Terminal initiated forward power control, which reduces forward link rate quantization loss due to excess transmit power. The Access Terminal reports to the Access Point the excess C/I estimate for the selected rate. The Access Point then reduces its transmit power by an appropriate amount when serving that Access Terminal. In another embodiment, the data transmission is scheduled based on an Access Point initiated forward power control. The Access Point varies its transmit power over time either randomly or in synchronism with neighboring Access Points in the communication system, which enables an increase in the throughput achieved by users that receive a significant amount of interference.
    Type: Application
    Filed: June 10, 2004
    Publication date: November 25, 2004
    Inventors: Charles E. Wheatley, Rashid A. Attar, Eduardo A.S. Esteves
  • Publication number: 20040202196
    Abstract: A method and an apparatus for adaptive data rate selection in a high data rate (HDR) communication system are disclosed. An exemplary HDR communication system defines a set of data rates, at which an access point (AP) may transmit data packets to an access terminal (AT). The transmission data rate is selected to maintain target packet error rate (PER). Each AT monitors signal quality metric of signals received from APs. An AT receiving forward link signals from multiple ATs identifies the AT associated with the highest quality forward link signal.
    Type: Application
    Filed: April 28, 2004
    Publication date: October 14, 2004
    Inventors: Nagabhushana T. Sindhushayana, Eduardo A.S. Esteves, Rashid A. Attar, Qiang Wu
  • Publication number: 20040179499
    Abstract: A method and an apparatus for rate control in a high data rate (HDR) communication system are disclosed. An exemplary HDR communication system defines a set of data rates, at which an access point (AP) may send data packets to an access terminal (AT). The data rate is selected to maintain targeted packet error rate (PER). The AT's open loop algorithm measures received signal to interference and noise ratio (SINR) at regular intervals, and uses the information to predict an average SINR over the next packet duration. The AT's closed loop algorithm measures a packet error rate (PER) of the received signal, and uses the PER to calculate a closed loop correction factor. The loop correction factor is added to the SINR value predicted by the open loop, resulting in an adjusted SINR.
    Type: Application
    Filed: March 24, 2004
    Publication date: September 16, 2004
    Inventors: Nagabhushana T. Sindhushayana, Rashid A. Attar, Eduardo A.S. Esteves
  • Patent number: 6760313
    Abstract: A method and an apparatus for adaptive data rate selection in a high data rate (HDR) communication system are disclosed. An exemplary HDR communication system defines a set of data rates, at which an access point (AP) may transmit data packets to an access terminal (AT). The transmission data rate is selected to maintain target packet error rate (PER). Each AT monitors signal quality metric of signals received from APs. An AT receiving forward link signals from multiple ATs identifies the AT associated with the highest quality forward link signal. The AT then evaluates the rate at which a tail probability of error is greater than or equal to a target tail probability of error. The AT then generates a prediction of a first data rate at which the PER of packets received from the identified AP will not exceed the target PER, and a prediction of a second data rate at which the PER of packets received from the selected AP will exceed the target PER.
    Type: Grant
    Filed: June 19, 2000
    Date of Patent: July 6, 2004
    Assignee: QUALCOMM Incorporated
    Inventors: Nagabhushana T. Sindhushayana, Eduardo A. S. Esteves, Rashid A. Attar, Qiang Wu
  • Patent number: 6757520
    Abstract: Methods and apparatus for selecting a serving sector in a high rate data (HDR) communication system are disclosed. An exemplary HDR communication system defines a set of data rates, at which a sector of an Access Point may send data packets to an Access Terminal. The sector is selected by the Access Terminal to achieve the highest data throughput while maintaining a targeted packet error rate. The Access Terminal employs various methods to evaluate quality metrics of forward and reverse links from and to different sectors, and uses the quality metrics to select the sector to send data packets to the Access Terminal.
    Type: Grant
    Filed: June 26, 2001
    Date of Patent: June 29, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Rashid A. Attar, Rajiv Vijayan, Roberto Padovani, Nagabhushana T. Sindhushayana, Qiang Wu, Peter J. Black, Eduardo A. S. Esteves
  • Patent number: 6751199
    Abstract: A method and an apparatus for rate control in a high data rate (HDR) communication system are disclosed. An exemplary HDR communication system defines a set of data rates, at which an access point (AP) may send data packets to an access terminal (AT). The data rate is selected to maintain targeted packet error rate (PER). The AT's open loop algorithm measures received signal to interference and noise ratio (SINR) at regular intervals, and uses the information to predict an average SINR over the next packet duration. The AT's closed loop algorithm measures a packet error rate (PER) of the received signal, and uses the PER to calculate a closed loop correction factor. The loop correction factor is added to the SINR value predicted by the open loop, resulting in an adjusted SINR. The AT maintains a look up table, which comprises a set of SINR thresholds that represent a minimum SINR necessary to successfully decode a packet at each data rate.
    Type: Grant
    Filed: April 24, 2000
    Date of Patent: June 15, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Nagabhushana T. Sindhushayana, Rashid A. Attar, Eduardo A. S. Esteves
  • Publication number: 20040098657
    Abstract: A method and an apparatus for quick retransmission of signals in a communication system are disclosed. A transmitting terminal, e.g., a base station, transmits signals in a form of packets to a receiving terminal, e.g., a subscriber station. The receiving terminal determines if the packet was intended for the receiving terminal, and if so, the receiving terminal demodulates the packet. The receiving terminal then computes a quality metric of the packet, and compares the computed quality metric with a quality metric contained in the packet. If the quality metrics match, the packet is declared correctly received, and is forwarded for further processing. If the quality metrics fail to match, the receiving terminal sends a request for retransmission of the packet. The transmitting terminal determines which packet needs to be retransmitted based on the request for retransmission. The transmitting terminal then schedules the packet for retransmission.
    Type: Application
    Filed: November 12, 2003
    Publication date: May 20, 2004
    Inventors: Ahmad Jalali, Eduardo A.S. Esteves, Nagabhushana T. Sindhushayana, Peter J. Black, Reshid A. Attar
  • Publication number: 20040091025
    Abstract: A system for providing an accurate interference value signal received over a channel and transmitted by an external transceiver. The system includes a first receiver section for receiving the signal, which has a desired signal component and an interference component. A signal extracting circuit extracts an estimate of the desired signal component from the received signal. A noise estimation circuit provides the accurate interference value based on the estimate of the desired signal component and the received signal. A look-up table transforms the accurate noise and/or interference value to a normalization factor. A carrier signal-to interference ratio circuit employs the normalization factor and the received signal to compute an accurate carrier signal-to-interference ratio estimate. Path-combining circuitry generates optimal path-combining weights based on the received signal and the normalization factor.
    Type: Application
    Filed: October 8, 2003
    Publication date: May 13, 2004
    Inventors: Nagabhushana T. Sindhushayana, Eduardo A.S. Esteves