Abstract: 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.

Abstract: A wireless communication receiver receiving a multiplexed signal comprising two or more signal streams calculates a received signal quality for the multiplexed signal as a function of stream-specific received signal qualities, determines one or more loss parameters indicative of variations in the stream-specific received signal qualities, and generates quality feedback based on such information. In turn, a transmitter controls the selection of one or more transmission parameters of the multiplexed signal based on the quality feedback, such that its transmit link adaptations account for the losses in received signal quality at the receiver arising from the variations in the stream-specific received signal qualities. The quality feedback may include calculated loss values, or parameter/penalties that permit loss calculation, and the method applies to both code multiplexing and spatial multiplexing.

Abstract: A wireless communication receiver receiving a multiplexed signal comprising two or more signal streams calculates a received signal quality for the multiplexed signal as a function of stream-specific received signal qualities, determines one or more loss parameters indicative of variations in the stream-specific received signal qualities, and generates quality feedback based on such information. In turn, a transmitter controls the selection of one or more transmission parameters of the multiplexed signal based on the quality feedback, such that its transmit link adaptations account for the losses in received signal quality at the receiver arising from the variations in the stream-specific received signal qualities. The quality feedback may include calculated loss values, or parameter/penalties that permit loss calculation, and the method applies to both code multiplexing and spatial multiplexing.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In a selective MIMO system, the mobile station provides channel quality feedback for one or more possible transmission mode. The mobile station provides channel quality feedback for a first mode regardless of channel conditions and determines whether to provide feedback for one or more additional modes based on current channel conditions.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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, ?D/P, may be obtained as a by-product of parametric estimation of impairment covariance associated with the received MIMO signal. In an exemplary method, a parametric impairment model is constructed for a received MIMO signal, the parametric model omitting code-reuse interference. Impairment covariance is measured, using, in one or more embodiments, received pilot symbol data. The parametric impairment model is fitted to the measured impairment covariance to obtain one or more scaling parameter values. A per-code energy value for a first data stream is then calculated from the one or more scaling parameter values.

Abstract: Channel Quality Indicator (CQI) tables are tailored to one or more cells of interest. Tailoring CQI tables to individual cells permits devices such as radio base stations to more reliably and accurately allocate radio resources to those cells since channel conditions vary from cell to cell. According to one embodiment, a table of CQI values is composed by analyzing information indicating channel quality in a cell of interest and generating at least one table of CQI values tailored to the cell of interest based on the information analyzed. The tailored CQI table may be deployed to another device for use in reporting channel quality information. The device may report channel quality by accessing the tailored CQI and identifying the range of CQI values that includes a channel quality estimate derived by the device. The device generates a channel quality information message based on the identified range of CQI values.

Abstract: 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.

Abstract: 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.

Abstract: According to a method and apparatus taught herein, the computation of intermediate combining weights considers impairment correlations common to two received signal streams, but does not account for cross-stream interference attributable to channel reuse between the two streams. Excluding consideration of channel reuse cross-stream interference from the computation of intermediate combining weights simplifies intermediate combining weight computation and increases computational robustness. Further, final combining weights, such as for Generalized Rake combining or equalization combining, may be obtained efficiently from the intermediate combining weights through the use of weight scaling factors, which do account for channel reuse cross-stream interference. Moreover, in at least some instances, the intermediate combining weights are of interest. For example, signal quality estimates for one or both streams may be computed from the corresponding intermediate combining weights.

Abstract: 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.

Abstract: 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.

Abstract: 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.