| Patent application number | Description | Published |
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| 20080304554 | METHOD AND APPARATUS FOR ESTIMATING IMPAIRMENT COVARIANCE MATRICES USING UNOCCUPIED SPREADING CODES - In one of its aspects, the technology concerns a method of processing a signal which includes physical data channels which have been channelized using spreading codes. The method comprises (1) despreading unoccupied spreading codes (e.g., codes which are essentially unobscured by traffic data) included in the signal to obtain unoccupied code despread values, (2) using the unoccupied code despread values to form an impairment covariance matrix; and (3) using the impairment covariance matrix along with a channel estimate to form a processing parameter. The processing parameter can be one of combining sets and a signal quality estimate. In another of its aspects, the technology concerns a coherent, linear equalizer apparatus configured to process a signal which includes physical data channels which have been channelized using spreading codes. The equalizer apparatus comprises plural delay fingers ( | 12-11-2008 |
| 20090310707 | TRANSMITTER AND METHOD FOR TRANSMITTING SOFT PILOT SYMBOLS IN A DIGITAL COMMUNICATION SYSTEM - A transmitter, channel coder, and method for coding and transmitting a sequence of symbols in a digital communication system utilizing soft pilot symbols. In one embodiment, the transmitter transmits a set of soft pilot symbols with higher reliability than the remaining symbols in the sequence by modulating the soft pilot symbols with a lower order modulation such as BPSK or QPSK while modulating the remaining symbols with a higher order modulation such as 16 QAM or 64 QAM. The transmitter shares the modulation type and location (time/frequency/code) of the soft pilot symbols with a receiver. Unlike traditional fixed pilots, the soft pilots still carry some data. Additionally, the soft pilots are particularly helpful in establishing the amplitude reference essential in demodulating the higher order modulation symbols. In another embodiment, soft pilot symbols are inserted by low-level puncturing of channel encoded bits and replacing the punctured bits with known bit patterns. | 12-17-2009 |
| 20090310708 | Transmitter and Method for Transmitting Soft Pilot Symbols in a Digital Communication System - A transmitter, channel coder, and method for coding and transmitting a sequence of symbols in a digital communication system utilizing soft pilot symbols. In one embodiment, the transmitter transmits a set of soft pilot symbols with higher reliability than the remaining symbols in the sequence by modulating the soft pilot symbols with a lower order modulation such as BPSK or QPSK while modulating the remaining symbols with a higher order modulation such as 16 QAM or 64 QAM. The transmitter shares the modulation type and location (time/frequency/code) of the soft pilot symbols with a receiver. Unlike traditional fixed pilots, the soft pilots still carry some data. Additionally, the soft pilots are particularly helpful in establishing the amplitude reference essential in demodulating the higher order modulation symbols. In another embodiment, soft pilot symbols are inserted by low-level puncturing of channel encoded bits and replacing the punctured bits with known bit patterns. | 12-17-2009 |
| 20100111239 | SYSTEM AND METHOD FOR PARALLEL INTERFERENCE CANCELLATION WITH COVARIANCE ROOT PROCESSING - A parallel interference cancellation (PIC) receiver incrementally removes interference from signals in parallel modules in successive stages. For each desired signal, as interfering signals are removed, corresponding updates to a data covariance matrix are modeled as computationally tractable rank-one updates to a root matrix of the covariance matrix. Processing of signals and/or covariance information may be initiated, continued, and/or halted at various stages, e.g., in response to signal or data quality. The PIC receiver using root matrix updates is applicable to a variety of demodulation techniques. | 05-06-2010 |
| 20110039544 | METHOD AND APPARATUS FOR INDICATING ANTICIPATED AVAILABLE DATA RATES IN A WIRELESS COMMUNICATION NETWORK - Contemporary wireless communication devices provide high data rate services, but the actual data rate achievable by a given device at a given time may be substantially less than a relevant maximum data rate that is theoretically achievable. Accordingly, among its several advantages, the present invention manages users' expectations for data service performance by providing them with an indication of the available data rate anticipated for data services, in relation to a maximum data rate. In one embodiment, a user's wireless communication device displays a data rate gauge that indicates the anticipated available rate in relation to the maximum rate. Doing so sets the user's expectations for data service performance in advance of engaging in the data service. | 02-17-2011 |
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| 20090154530 | MIMO/Transmit Diversity Channel Estimation - A receive station of the present invention despreads a received signal over multiple successive symbol periods of an extended measurement period to determine individual channel estimates over each symbol period of an extended period for multiple pilot signals. In one example, the extended measurement period comprises two extended periods, each of which comprise two symbol periods. As a result, the present invention provides channel estimates sufficient for both slow and fast fading conditions. The receive station determines a combined channel estimate for the pilot signals over each symbol period of an extended period by despreading the received signal over each symbol period of an extended measurement period using a common spreading sequence. Based on the combined channel estimates, the receive station determines individual channel estimates for each pilot signal over each symbol period of the extended period. | 06-18-2009 |
| 20090154531 | Multi-Pass Parameter Estimation for G-Rake Receiver - In a parametric G-Rake receiver, a method an apparatus computes initial estimates of one or more scaling parameters and initial combining weights for the parametric G-Rake receiver; estimates the SINR of a received signal based on a mean pilot symbol estimate and the initial combining weights; computes revised estimates for one or more scaling parameters based on the estimated SINR and the initial combining weights; and computes revised combining weights based on one or more revised scaling parameter estimates. | 06-18-2009 |
| 20090154576 | MIMO/Transmit Diversity Channel Estimation - A receive station of the present invention despreads a received signal over both long and short despreading periods to determine individual channel estimates over each symbol period of an extended period for multiple pilot signals. As a result, the present invention provides channel estimates sufficient for both slow and fast fading conditions. The receive station determines an average channel estimate for each of the pilot signals over the extended period by despreading the received signal over the extended period using mutually orthogonal extended spreading sequences. The receive station further determines a combined channel estimate for the pilot signals over each symbol period of the extended period by despreading the received signal over each symbol period using a common spreading sequence. Based on the average and combined channel estimates, the receive station determines individual channel estimates for each pilot signal over each symbol period of the extended period. | 06-18-2009 |
| 20090257477 | Method and Apparatus for Successive Interference Subtraction with Covariance Root Processing - Methods and apparatus for processing a composite communication signal comprising two or more received signals of interest are disclosed. An interference-suppressing receiver, which may comprise a G-Rake receiver or a linear chip equalizer, utilizes a square-root covariance matrix in processing received signals, where the square-root covariance matrix represents impairment covariance or data covariance for the composite communication signal. In an exemplary method, a receiver detects symbols, corresponding to a signal of interest, from the composite communication signal, using processing weights calculated from a square-root covariance matrix and a net channel response for the signal of interest. The method further comprises calculating a reconstructed version of the signal of interest from the detected first symbols, generating an updated communication signal by subtracting the reconstructed version of the first signal of interest from the composite communication signal, and updating the square-root covariance matrix to obtain an updated square-root covariance matrix. | 10-15-2009 |
| 20090304132 | Method and Apparatus for Efficient Estimation of Interference in a Wireless Receiver - Methods and apparatus for determining an impairment covariance matrix for use in an interference-suppressing CDMA receiver are disclosed. In several of the disclosed embodiments, precise information regarding signal propagation delays is not needed. An exemplary method includes the selection of a plurality of processing delays for processing a received CDMA signal. Net channel coefficients for the processing delays are estimated and used to calculate an impairment covariance matrix. The impairment covariance matrix is calculated as a function of the estimated net channel coefficients and the processing delays, without estimating a propagation medium channel response for the received signal. | 12-10-2009 |
