Patents Represented by Attorney Thien T. Nguyen
  • Patent number: 6775254
    Abstract: Techniques for transmitting voice/data and packet data services such that packet data transmissions have less impact on voice/data transmissions. In one aspect, voice/data and packet data can be multiplexed within a transmission interval such that the available resources are efficiently utilized. In another aspect, the amount of variation in the total transmit power from a base station is controlled to reduce degradation to transmissions from this and other base stations. In a specific method for concurrently transmitting a number of types of data, a first data type (e.g., voice, overhead, and some data) and a second data type are respectively processed in accordance with first and second signal processing schemes to generate first and second payloads, respectively. First and second partitions are then defined in a transmission interval. The first and second payloads are time multiplexed into the first and second partitions, respectively, and the multiplexed payloads are transmitted.
    Type: Grant
    Filed: November 9, 2000
    Date of Patent: August 10, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Serge Willenegger, Stein A. Lundby
  • Patent number: 6771706
    Abstract: Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI.
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: August 3, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Fuyun Ling, Jay R. Walton, Steven J. Howard, Mark Wallace, John W. Ketchum
  • Patent number: 6771700
    Abstract: Method and apparatus for transmitting a signal at a predetermined level of reliability using retransmission of erroneously transmitted frames so as to minimize total transmission energy. The transmitting station evaluates the frame error rate (FER) as a function of energy. Next, the transmitting station determines a combination of initial transmission energies and retransmission energies that will provide the target level of reliability while minimizing the total transmission energy employed in the initial transmission and the retransmissions. The transmitting station transmits a frame with an initial transmission energy. Employing conventional feedback methods the transmitting station is alerted to the occurrence of frame errors at the receiving station. The transmitting station upon notification of a frame error retransmits the frame with an energy determined to minimize the total energy required to transmit the frame with a predetermined level of reliability.
    Type: Grant
    Filed: October 22, 1999
    Date of Patent: August 3, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Leonid Razoumov, Jack Holtzman, Stein A. Lundby
  • Patent number: 6763244
    Abstract: Techniques to adjust the setpoint of a power control loop in a wireless communication system. The setpoint may be adjusted based on frame status indicative of erased/good decoded frames, one or more (typically soft) metrics indicative of the confidence in the decoded results, power surplus/deficit indicative of the difference between the received signal quality and the setpoint, setpoint surplus/deficit indicative of the difference between the setpoint and a threshold Eb/Nt needed for the desired level of performance, or a combination thereof. The metrics may include re-encoded symbol error rate, re-encoded power metric, modified Yamamoto metric, minimum or average LLR among decoded bits, number of decoding iterations, and possibly others. The setpoint may be adjusted in different manners and/or by different amounts depending on the above-noted factors. The techniques may be employed for forward and/or reverse links in CDMA systems.
    Type: Grant
    Filed: March 15, 2001
    Date of Patent: July 13, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Tao Chen, Jack M. Holtzman, Fuyun Ling, Keith Saints, Nagabhushana Sindhushayana, Charles E. Wheatley, III
  • Patent number: 6760388
    Abstract: Techniques for processing a data transmission at the transmitter and receiver. In an aspect, a time-domain implementation is provided which uses frequency-domain singular value decomposition and “water-pouring” results to derive time-domain pulse-shaping and beam-steering solutions at the transmitter and receiver. The singular value decomposition is performed at the transmitter to determine eigen-modes (i.e., spatial subchannels) of the MIMO channel and to derive a first set of steering vectors used to “precondition” modulation symbols. The singular value decomposition is also performed at the receiver to derive a second set of steering vectors used to precondition the received signals such that orthogonal symbol streams are recovered at the receiver, which can simplify the receiver processing.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: July 6, 2004
    Assignee: Qualcomm Incorporated
    Inventors: John W. Ketchum, Mark Wallace, Steven J. Howard, Jay Rod Walton
  • Patent number: 6760584
    Abstract: A system for accessing broadcast SMS messages over a wireless communication system. A base station transmits SMS messages periodically and aperiodically over a broadcast channel. The base station allocates periodic slots in the broadcast channel for each of the subscriber services providing the SMS messages and transmits slot parameters to mobile units. Using the slot parameter information, the mobile units periodically wake up to scan the broadcast channel. The period for each category of broadcast SMS messages may be different and the period may apply to a single broadcast channel. Messages arriving aperiodically can be queued and transmitted in pre-scheduled broadcast channel frames. Messages with inter-arrival interval greater than the specified transmission period are simply repeated.
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: July 6, 2004
    Assignee: Qualcomm, Incorporated
    Inventor: Yu-Cheun Jou
  • Patent number: 6757320
    Abstract: A forward link power control mechanism measures the reverse link power control bits which are transmitted on the forward traffic channel. At the remote station, the reverse link power control bits from multiples base stations or multiple signal paths are measured, combined, and filtered to yield an improved measurement of the forward link signal quality. The reverse link power control bits which are deemed unreliable are omitted from use in the power control loop. The remote station generates a set of forward link power control bit in accordance with the measurements and transmits these bits to all base stations in communication with the remote station. Each base station adjusts its gain of the forward traffic channel in accordance to its measurement of the forward link power control bit.
    Type: Grant
    Filed: March 6, 2002
    Date of Patent: June 29, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Edward G. Tiedemann, Jr., Keith W. Saints
  • Patent number: 6757335
    Abstract: A method is taught for improving the transmission of information signals in a communications system having a base station and a remote station. First and second transmission links are established with the remote station. An information signal is encoded to provide an encoded information signal having more bits than the information signal. First and second transmission signals are provided wherein each transmission signal has bits selected from the encoded information signal. Each of the first and second transmission signals is transmitted to the remote station by way of a respective one of the first and second transmission links. The remote station receives and combines the first and second transmission signals transmitted by the remote station to provide a combined encoded signal. The combined encoded signal is decoded by the remote station to provide the information signal.
    Type: Grant
    Filed: March 11, 2003
    Date of Patent: June 29, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Stein Lundby, Keith Saints
  • Patent number: 6751206
    Abstract: In a CDMA data communication system capable of variable rate transmission, utilization of beam switching techniques decreases the average interference caused by transmissions of a base station to subscriber stations within a cell, and in neighboring cells. Base stations utilize multiple transmit antennas, each transmitting signals at controlled amplitudes and phases, to form transmit signal corresponding to sector divisions. Data and reference signals are transmitted along sector division beams that alternate according to fixed time slots in order to increase system capacity and data rates by maximizing carrier-to-interference ratios (C/I) measured at subscriber stations.
    Type: Grant
    Filed: June 29, 2000
    Date of Patent: June 15, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Roberto Padovani, Paul E. Bender, Ahmad Jalali, Bruce Judson, Charles E. Wheatley, III
  • Patent number: 6751187
    Abstract: Techniques to select transmission channels for use for data transmission and to process and transmit data over the selected transmission channels. Transmission channels available for use are segregated into one or more groups, with each group including any number of channels. With selective channel transmission, only “good” channels in each group are selected (e.g., based on the channels' received SNRs and an SNR threshold), “bad” channels are not used, and the total available transmit power for the group is (e.g., uniformly) distributed across only the good channels. Each group may also be associated with a respective coding and modulation scheme, and data for each group may be coded and modulated based on the scheme selected for the group. Improved performance is achieved by using only good channels in each group and matching the data processing for the selected channels to the capacity achievable by the channels.
    Type: Grant
    Filed: June 26, 2001
    Date of Patent: June 15, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Jay R. Walton, John W. Ketchum
  • Patent number: 6751193
    Abstract: A method of and apparatus for controlling data transfer between two stations comprises a link manager for controlling allocation of available channels in a plurality of communications links. In each of the communications links data is transferred between two stations in at least one channel. Data for transfer from a data source is buffered in a data buffer. A controller determines latency in the buffer from the amount of data in the buffer and the rate at which data is being output from the buffer. The controller generates a request for a change in the allocation of channels in a communications link between two stations depending on the latency in the buffer and preset threshold values. The link manager is responsive to a request generated by the controller either to allocate a different number of channels to the communications link or to generate a refusal of the request.
    Type: Grant
    Filed: June 26, 1998
    Date of Patent: June 15, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Abhijit S. Kudrimoti, Mark R. Gibbard, Abhijit G. Shanbhag
  • Patent number: 6747994
    Abstract: Methods and apparatus are presented to select optimal transmission formats for transmissions to a single user or simultaneous transmissions to multiple users. Priority information and channel state information associated with each user are used to determine the optimal transmit formats. In particular, said formation is used to maximize a given revenue function that enhances system throughput while maintaining fairness among users. Once transmit formats are determined, any unallocated system resources, such as unused Walsh codes or transmission power, can be evenly or proportionately distributed among the users.
    Type: Grant
    Filed: October 17, 2001
    Date of Patent: June 8, 2004
    Assignee: Qualcomm, Incorporated
    Inventors: David Puig Oses, Yongbin Wei, Stein A. Lundby
  • Patent number: 6747958
    Abstract: Techniques for determining valid (i.e., supported) TFCs from among all configured TFCs for normal and compressed modes. These techniques maintain sufficient historical information such that “TFC qualification” may be accurately performed. In a first scheme, Tx_power_requirement states are maintained for different combinations of each TFC. One combination is applicable for each TFC at each TFC interval, and valid TFCs are determined from applicable combinations in the proper state(s). In a second scheme, two Tx_power_requirement states are maintained for each TFC for the normal and compressed modes. In a third scheme, a single Tx_power_requirement state is maintained for each TFC for both modes based on a particular relative power requirement. In a fourth scheme, Tx_power_requirement states are maintained for a set of relative “bins” that cover the total range of required transmit power for all TFCs. And in a fifth scheme, a set of relative power requirement thresholds are maintained.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: June 8, 2004
    Assignee: Qualcomm, Incorporated
    Inventors: Alkinoos Hector Vayanos, Serge Willenegger, Josef Blanz
  • Patent number: 6744743
    Abstract: In some aspects, each cell in the communications system can be designed to operate in accordance with a set of back-off factors that identify the reductions in peak transmit power levels for the channels associated with the back-off factors. The back-off factors are defined to provide the required power to a large percentage of the users while reducing the amount of interference. In some other aspects, the cells operate using an adaptive reuse scheme that allows the cells to efficiently allocate and reallocate the system resources to reflect changes in the system. A reuse scheme is initially defined and resources are allocated to the cells. During operation, changes in the operating conditions of the system are detected and the reuse scheme is redefined as necessary based on the detected changes. In yet other aspects, techniques are provided to efficiency schedule data transmissions and to assign channels to users.
    Type: Grant
    Filed: October 23, 2002
    Date of Patent: June 1, 2004
    Assignee: Qualcomm Incorporated
    Inventors: Jay R. Walton, Mark Wallace, Jack Holtzman, Franklin P. Antonio
  • Patent number: 6741861
    Abstract: A method and apparatus for rapidly assigning traffic channels to a plurality of mobile stations in a wide area high-speed packet data cellular communication system. Mobile stations transmit access probes on randomly selected access channels to selected base stations to initiate traffic channel assignments. The access probe comprises a pilot preamble, a traffic channel request, and a pilot/data request channel (DRC). The pilot preamble allows the selected base station to easily detect the access probe transmission. The traffic channel request includes data that identifies the mobile station. Immediately after transmitting the traffic channel request, the mobile station begins communicating with the base station on both the forward and reverse communication links. The selected base station immediately supervises the mobile station's transmission power. The mobile station selects from a group of available power control sub-channels.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: May 25, 2004
    Assignee: Qualcomm, Incorporated
    Inventors: Paul E. Bender, Matthew S. Grob, Gadi Karmi
  • Patent number: 6731668
    Abstract: In one disclosed embodiment, an input bit stream is supplied to a trellis code block. For example, the trellis code block can perform convolutional coding using a rate 6/7 code. The output of the trellis code block is then modulated using, for example, trellis coded quadrature amplitude modulation with 128 signal points or modulation symbols. The sequence of modulation symbols thus generated can be diversity encoded. The diversity encoding can be either a space time encoding, for example, or a space frequency encoding. The sequence of modulation symbols, or the sequence of diversity encoded modulation symbols, is fed to two or more orthogonal Walsh covers. For example, replicas of the modulation symbol sequences can be provided to increase diversity, or demultiplexing the modulation symbol sequences can be used to increase data transmission rate or “throughput”. The outputs of the Walsh covers are fed as separate inputs into a communication channel.
    Type: Grant
    Filed: January 5, 2001
    Date of Patent: May 4, 2004
    Assignee: Qualcomm Incorporated
    Inventor: John W. Ketchum