Patents by Inventor Rashid A. Attar

Rashid A. Attar 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: 6876866
    Abstract: A power control mechanism having a number of states and suitable for used in a communication system in which data transmissions are not continuous (i.e., bursty in nature). In one embodiment, a power control unit includes a data processor, a state machine, and a threshold adjustment element. The data processor receives and processes an input signal to provide status of data frames received from the input signal for a particular data transmission. The state machine receives the frame status and provides a current state for the power control unit. The current state is indicative of a status of a particular communication session that includes the data transmission, and is one of a number of possible states. The threshold adjustment element receives the frame status and the current state and adjusts a power control setpoint in response thereto. The setpoint is used to control the signal quality of the input signal and is adjusted in accordance with a particular adjustment scheme (i.e.
    Type: Grant
    Filed: July 13, 2000
    Date of Patent: April 5, 2005
    Assignee: Qualcomm Incorporated
    Inventors: Fatih Ulupinar, Rashid Attar, Eduardo Esteves
  • Patent number: 6873831
    Abstract: An apparatus according to one embodiment of the invention includes a transmitter. The transmitter receives an RF signal and produces at least two modulated signals based on the RF signal. Each of the modulated signals is coupled to a respective antenna. The combined radiation pattern of the antennas varies in an angular direction over time. In a system according to one embodiment of the invention, a base station including such an apparatus receives channel quality indications from mobile units and schedules data transmissions to the mobile units accordingly.
    Type: Grant
    Filed: April 1, 2002
    Date of Patent: March 29, 2005
    Assignee: Qualcomm Incorporated
    Inventors: Rashid A. Attar, Charles E. Wheatley, III
  • 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: 20050020295
    Abstract: An apparatus and a method for a control channel power allocation in a communication system are disclosed. The method of control channel power allocation in an embodiment includes sorting a plurality of access terminals in an order of increasing required medium access control (MAC) channel power into a plurality of bins, sorting the access terminals with equal required MAC channel power in an order of decreasing forward link signal to interference and noise ratio (FL_SINR) if two or more access terminals have equal required MAC channel power, and determining total available ARQ power based upon total MAC channel power, total power allocated to reverse power control (RPC) channels, and total power allocated to reverse activity bit (RAB) channels.
    Type: Application
    Filed: August 18, 2003
    Publication date: January 27, 2005
    Inventors: Rashid Attar, Naga Bhushan, Mingxi Fan
  • Publication number: 20050014524
    Abstract: An access terminal (206) is configured for wireless communication with an access network (204) within a sector (1032). The access terminal (206) includes a transmitter (2608) for transmitting a reverse traffic channel to the access network (204), an antenna (2614) for receiving signals from the access network (204), a processor (2602) and memory (2604) in electronic communication with the processor (2602). Instructions are stored in the memory (2604). The instructions are executable estimate a current value of a reverse activity bit (1444) transmitted by the access network (204). Per flow power allocation may be decreased on increased based on an estimated current value of the reverse activity bit.
    Type: Application
    Filed: July 13, 2004
    Publication date: January 20, 2005
    Inventors: Christopher Lott, Naga Bhushan, Rashid Attar, Jean Au, Donna Ghosh
  • Publication number: 20050013282
    Abstract: An access terminal (206) configured for wireless communication with an access network (204) within a sector (1032). The access terminal (206) includes a transmitter (2608) for transmitting a reverse traffic channel to the access network (204), an antenna (2614) for receiving signals from the access network (204), a processor (2602) and memory (2604) in electronic communication with the processor (2602). Instructions stored in the memory (2604) implement a method of determining whether a current power allocation grant (1374) for a flow (1216) on the access terminal (206) has been received from the access network (204). If the current power allocation grant (1374) is still active, a current power allocation (1338a) for the flow is set equal to the current power allocation grant (1374). If the current power allocation grant (1374) has not been received, the current power allocation (1338a) for the flow is determined.
    Type: Application
    Filed: July 15, 2004
    Publication date: January 20, 2005
    Inventors: Christopher Lott, Naga Bhushan, Rashid Attar, Jilei Hou
  • Publication number: 20050013271
    Abstract: An access terminal (206) configured for wireless communication with an access network (204) within a sector (1032). The access terminal includes a transmitter (2608) for transmitting a reverse traffic channel to the access network (204), an antenna (2614) for receiving signals from the access network (204), a processor (2602) and memory (2604) in electronic communication with the processor (2602). Instructions stored in the memory (2604) implement, for each flow (1216) of a plurality of flows on the access terminal (206), determining the flow's total available power (1238). The access terminal's total available power (1234) is determined by summing each flow's total available power (1238). A packet is transmitted to the access network (204) at a power level that does not exceed the access terminal's total available power (1234).
    Type: Application
    Filed: July 15, 2004
    Publication date: January 20, 2005
    Inventors: Christopher Lott, Naga Bhushan, Donna Ghosh, Rashid Attar
  • 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: 20040202136
    Abstract: Reverse Link (RL) data rate allocation in a High Data Rate (such as 1xEV-DO) system as a function of Forward Link (FL) channel quality. Rate shaping of a throughput profile for multiple Access Terminals (ATs) is performed by adjusting transition probabilities associated with a data rate allocation algorithm. The RL maximum data rate per AT is adjusted to reduce the loading in a designated area and result in rate shaping of the cell and/or sector. In one embodiment, the maximum data rates are adjusted as a function of the FL Signal to Interference and Noise Ratio (SINR), such as measured per serving sector or as a captured sum total of FL SINR. In still another embodiment, the maximum data rates are adjusted as a function of differences in rise-over-thermal values between neighboring sectors.
    Type: Application
    Filed: November 14, 2002
    Publication date: October 14, 2004
    Inventors: Rashid A. Attar, Christopher G. Lott
  • Publication number: 20040203979
    Abstract: An apparatus according to one embodiment of the invention includes a transmitter. The transmitter receives an RF signal and produces at least two modulated signals based on the RF signal. Each of the modulated signals is coupled to a respective antenna. The combined radiation pattern of the antennas varies in an angular direction over time. In a system according to one embodiment of the invention, a base station including such an apparatus receives channel quality indications from mobile units and schedules data transmissions to the mobile units accordingly.
    Type: Application
    Filed: April 1, 2002
    Publication date: October 14, 2004
    Inventors: Rashid A. Attar, Charles E. Wheatley
  • 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
  • Publication number: 20040160984
    Abstract: Method and apparatus for variable length Physical Layer (PL) packet generation. Multiple Security Layer (SL) packets may be multiplexed into a single PL packet to increase efficiency, wherein the SL packets may have variable lengths. In one embodiment, different format SL packets for different users are combined into capsules that form the PL packet. Shorter packets are for users in poor channel conditions or requiring smaller amounts of data due to the applications and the accompanying Quality of Service (QoS) requirements. In one embodiment, a modified Preamble structure provides for Unicast or multi-user packets. Alternate embodiment provides modified Rate Sets, a mechanism for identifying ACK from a single-user packet or a multiplexed packet (delayed ACK). ON/OFF keying for ACK channel v/s bi-polar keying used in IS-856, and/or multi-valued interpretation of DRC.
    Type: Application
    Filed: February 18, 2003
    Publication date: August 19, 2004
    Inventors: Nagabhushana Sidhushayana, Rashid A. Attar, Ramin Rezaiifar
  • 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: 20040110525
    Abstract: Systems and techniques for controlling transmission power involve receiving a first to second channel power ratio, receiving a first to second channel power ratio, adjusting the power ratio if a combined power of a plurality of channels exceeds a threshold, the channels including the first and second channels, and computing gain of the first channel as a function of the power ratio.
    Type: Application
    Filed: June 16, 2003
    Publication date: June 10, 2004
    Inventors: Peter J. Black, Nagabhushana Sindhushayana, Raghu Challa, Rashid Attar
  • Patent number: 6741661
    Abstract: A method and system that reduces the peak-to-average power ratio of a reverse link signal is described. A baseband structure implements a peak reduction technique using peak windowing. A non-rectangular window is used to distort the signal. One embodiment of the window is an inverted-raised cosine with the peak reduction a function of the relative difference in the squared-magnitude of the envelope relative to that of the desired peak-to-average power ratio. Multiple passes through the peak-reduction function may be performed until a desired target peak-to-average power ratio is achieved.
    Type: Grant
    Filed: May 22, 2001
    Date of Patent: May 25, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Charles E. Wheatley, III, Rashid A. Attar
  • Publication number: 20040095960
    Abstract: Reverse Link (RL) data rate allocation in a High Data Rate (such as 1xEV-DO) system as a function of Forward Link (FL) channel quality. Rate shaping of a throughput profile for multiple Access Terminals (ATs) is performed by adjusting transition probabilities associated with a data rate allocation algorithm. The transition probabilities are adjusted to encourage transitions in a desired direction. In one embodiment, the transition probabilities are adjusted as a function of the FL Signal to Interference and Noise Ratio Ratio (SINR), such as measured per serving sector or as a captured sum total of FL SINR. In another embodiment, the transition probabilities are adjusted as a function of the historical loading condition of the system. In still another embodiment, the transition probabilities are adjusted as a function of differences in rise-over-thermal values between neighboring sectors.
    Type: Application
    Filed: November 14, 2002
    Publication date: May 20, 2004
    Inventors: Rashid A. Attar, Christopher G. Lott
  • Publication number: 20040095908
    Abstract: In a disclosed embodiment, signal levels of the active sectors of an access terminal are compared with the signal level of the current serving sector of the access terminal. Next, a delta credit is accumulated. If a DRC lock bit is available, then an accumulated total credit is authorized to produce an authorized accumulated total credit. Afterwards, a new serving sector is identified from a pool of candidate sectors based on the signal levels of the active sectors and the authorized accumulated total credits.
    Type: Application
    Filed: November 12, 2003
    Publication date: May 20, 2004
    Inventors: Qiang Wu, Nagabhushana Sindhushayana, Peter J. Black, Rajiv Vijayan, Rashid Attar