Patent application number | Description | Published |
20110105046 | Method and Apparatus for Generating Channel Quality Information for Wireless Communication - A method and apparatus for generating channel quality information, such as may be used for transmit link adaptation, provide different operating modes, such as a first mode that may be used when propagation channel estimates are not reliable, and a second mode that may be used when the propagation channel estimates are reliable. In one or more embodiments, channel quality information is generated using receiver performance information that characterizes receiver performance in terms of a defined channel quality metric, e.g., supported data rates, for different values of receiver input signal quality over a range of propagation channel realizations. Channel quality information can be generated by selecting channel quality metrics according to receiver input signal quality and a desired probability of meeting a defined performance requirement over a range of propagation channel realizations, or by selecting channel quality metrics according to receiver input signal quality and particularized propagation channel realizations. | 05-05-2011 |
20110305193 | Signaling Mechanism for Inter-RAT Carrier Aggregation - A signaling mechanism informs a Radio Network Controller of the radio access technology associated with data packets forwarded to the Radio Network Controller from base stations supporting multiple radio access technologies. With this information, the Radio Network Controller can associate received data with the corresponding radio access technologies, and thus manage differing physical layer procedures, such as outer-loop power control, for the radio access technologies. In an example method, first and second data units transmitted by a mobile station over first and second radio access technologies, respectively, are forwarded from one or more base stations to a network control node for further processing. A control message associated with at least some of the data units is also sent to the network control node, the control message indicating the radio access technology over which the associated data units were transmitted. | 12-15-2011 |
20120027115 | Method and Apparatus for Impairment Correlation Estimation in a Wireless Communication Receiver - A wireless communication receiver improves signal impairment correlation estimation in MIMO/MISO systems by considering different transmit power allocations and different transmit antenna power distributions in its impairment correlation calculations. The receiver may be implemented in according to a variety of architectures, including, but not limited to, Successive Interference Cancellation (SIC) Generalized RAKE (G-RAKE), Joint Detection (JD) G-RAKE, and Minimum Mean Squared Error (MMSE) G-RAKE. Regardless of the particular receiver architecture adopted, the improved impairment correlations may be used to calculate improved (RAKE) signal combining weights and/or improve channel quality estimates for reporting by receivers operating in Wideband CDMA (W-CDMA) systems transmitting HSDPA channels via MIMO or MISO transmitters. A transmitter may be configured to facilitate impairment correlation determinations by wireless communication receivers operating in MIMO/MISO environments, by signaling one or more values, e.g., data-to-pilot signal transmit power ratios and/or transmit antenna power distributions for the data and pilot signals. | 02-02-2012 |
20120188951 | Preferential Allocation of Different Length Scrambling Codes - A base station herein assists a radio network controller (RNC) to allocate scrambling codes in a cell. The base station's assistance advantageously permits the RNC to allocate different length scrambling codes to different mobile terminals (or downlink carriers) in the cell. Specifically, the base station determines a preference for whether the length of a scrambling code to be allocated to each terminal or carrier should be short or long, based on whether uplink communications transmitted by the terminal, or downlink communications transmitted over the carrier, are to be processed with a high-complexity receiver or a low-complexity receiver. The RNC receives these preferences from the base station and takes them into account in order to allocate either a short scrambling code or a long scrambling code to each terminal or downlink carrier in the cell. The RNC then propagates the scrambling code allocations throughout the cell. | 07-26-2012 |
Patent application number | Description | Published |
20080291978 | Receiver Parametric Covariance Estimation for Transmit Diversity - A parametric form of G-Rake and chip equalization for closed-loop transmit diversity is provided, that accounts for impairment correlation between transmit antennas. In a closed-loop transmit diversity system, the base station transmits a signal from two or more antennas, using one of a predetermined set of relative phase offsets at one of the antennas. The parametric estimation of the impairment or data covariance is performed by summing terms, including a term for each possible phase offset. The terms are weighted by fitting parameters. The fitting parameters are jointly solved by fitting the impairment or data covariance estimate to a measured impairment or data covariance. In another aspect, a measured impairment covariance is formed by exploiting a special relationship between the pilot channels of the different transmit antennas. | 11-27-2008 |
20090213909 | Code Power Estimation for MIMO Signals - Methods and apparatus for estimating code-reuse interference associated with a received multi-stream multiple-input multiple-output (MIMO) signal are disclosed. An estimate for the data-to-pilot power ratio, Γ | 08-27-2009 |
20090213910 | Code Power Estimation for MIMO Signals - Methods and apparatus for estimating code-reuse interference associated with a received multi-stream multiple-input multiple-output (MIMO) signal are disclosed. In an exemplary method, impairment covariance associated with the received multi-stream MIMO signal is measured, and first and second sets of samples for received traffic data symbols are collected, using first and second sets of RAKE combining weights corresponding to effective net channel responses for first and second streams of the multi-stream MIMO signal, respectively. A per-code energy value for at least one stream of the received multi-stream MIMO signal is computed, as a function of the measured impairment covariance, the effective net channel responses for the first and second streams, and the first and second sets of samples. Finally, code-reuse interference associated with the first stream is calculated, as a function of the per-code energy value and the effective net channel response corresponding to the first stream. | 08-27-2009 |
20090213944 | Receiver Parametric Covariance Estimation for Precoded MIMO Transmissions - A model-based technique for estimating signal impairments that can accommodate various transmitted signal configurations, including closed-loop transmit diversity signals and pre-coded MIMO signals, is disclosed. In an exemplary method, an impairment model is constructed for a received composite information signal comprising at least a first data stream transmitted from first and second antennas according to a first antenna weighting vector. The impairment model includes one or more model terms scaled by corresponding scaling parameters, wherein the model terms capture propagation channel effects and are independent of the first antenna weighting vector, and wherein the scaling parameters capture effects of the first antenna weighting vector. A parametric estimate of the impairment covariance is calculated using the impairment model. | 08-27-2009 |
20090213945 | Reduced Complexity Parametric Covariance Estimation for Precoded MIMO Transmissions - A model-based technique for estimating impairment covariance associated with a MIMO signal is disclosed. In an exemplary method, an impairment model is constructed for a received composite information signal comprising at least a first data stream transmitted from first and second antennas according to a first antenna weighting vector. The impairment model includes first and second model terms corresponding to the first and second antennas, respectively, but in several embodiments does not include a cross-antenna interference term. In another embodiment, an impairment model for a received MIMO signal is constructed by computing an impairment model term for each antenna and an additional term to account for preceding interference in a single-stream MIMO transmission scenario. The impairment terms are grouped so that only two associated scaling terms are unknown; values for the scaling terms are estimated by fitting the model to measured impairment covariance values. | 08-27-2009 |
20090268787 | Method and Apparatus for Compensating for Processing Timing Misalignment in a Communication Receiver - According to the teachings presented herein, a wireless communication apparatus compensates for timing misalignment in its received signal processing. In at least one embodiment, the apparatus estimates a set of path delays for a received signal and sets processing delays on the estimated path delays. The apparatus jointly hypothesizes combinations of fractional timing offsets for two or more paths, and computes a decision metric for each joint hypothesis that indicates the accuracy of the joint hypothesis. As non-limiting examples, the decision metric may be a signal quality metric, or a distance metric (such as between a measured net channel response and an effective net channel response reconstructed as a function of the combination of fractional timing offsets included in the joint hypothesis). The apparatus evaluates the decision metrics to identify a best estimate of timing misalignment, and correspondingly compensates coherent processing of the received signal. | 10-29-2009 |
20100183064 | Method and Apparatus for Generating Channel Quality Information for Wireless Communication - A method and apparatus for generating channel quality information, such as may be used for transmit link adaptation, provide different operating modes, such as a first mode that may be used when propagation channel estimates are not reliable, and a second mode that may be used when the propagation channel estimates are reliable. In one or more embodiments, channel quality information is generated using receiver performance information that characterizes receiver performance in terms of a defined channel quality metric, e.g., supported data rates, for different values of receiver input signal quality over a range of propagation channel realizations. Channel quality information can be generated by selecting channel quality metrics according to receiver input signal quality and a desired probability of meeting a defined performance requirement over a range of propagation channel realizations, or by selecting channel quality metrics according to receiver input signal quality and particularized propagation channel realizations. | 07-22-2010 |