Abstract: 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.

Abstract: Coded digital data symbols sent through a transmission channel of a communications network are received in a receiver. Estimates (y) represented by a first number (a+b) of bits are calculated, and modified estimates (y?) represented by a second number (c) of bits provided therefrom, the second number being lower than the first number. An amplitude value is calculated for each estimate (y), and an averaged amplitude value calculated for a number of amplitude values. A scaling factor (s) is calculated form the averaged amplitude value, and scaled estimates generated in dependence of die scaling factor. The scaling factor is used for a number of scaled estimates corresponding to the number of amplitude values for which the averaged amplitude value was calculated. Thus a better scaling factor is provided for most channel cases, which can still be calculated with the limited computational resources of a terminal for such networks.

Abstract: In a wireless receiver, an estimated decision boundary for use in detecting symbol values from one group of combined received symbols is calculated based on a estimated traffic-to-pilot channel scaling ratio or an estimated decision boundary corresponding to another group of combined received symbols. By properly combining the information derived from the latter group of combined received symbols with channel estimation information for the former group, a decision boundary estimate for the former group can be obtained without the use of amplitude or power information for the latter group of symbols.

Abstract: A method and a receiver for receiving coded digital data symbols sent from a transmitter through a transmission channel of a communications network is adapted to calculate first symbol estimates (y) of sent data symbols from the received data symbols, each of the first symbol estimates (y) having a first bitwidth (a+b), provide a scaling factor (s) and using the scaling factor (s) to scale the first symbol estimates, truncate the scaled symbol estimates (ysc) to a second, lower bitwidth (c) and thereby providing second symbol estimates (yt).

Abstract: Methods and apparatus for processing a received multi-stream (MIMO) signal, and in particular for estimating a per-code traffic-channel-to-pilot power ratio for the MIMO signal are disclosed. An exemplary method includes the calculation of an average symbol amplitude or average symbol power level from a plurality of de-spread traffic channel symbols received in a first transmission slot and the estimation of a corresponding pilot symbol amplitude or pilot symbol power level, based on an estimated propagation channel response and at least one of a plurality of precoding vectors used to generate the MIMO signal. A per-code traffic-channel-to-pilot power ratio for the first transmission slot is computed by dividing the average symbol amplitude or average symbol power level by the corresponding pilot symbol amplitude or pilot symbol power level.

Abstract: A receiver utilizes pilot channel propagation channel estimates and a signal-to-interference metric derived from the pilot channel to form combining weights for use in obtaining soft symbols from a desired channel for subsequent decoding. The soft symbols thus obtained are substantially independent of the pilot channel amplitude.

Abstract: 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.

Abstract: A method is described for adjusting soft values in a code block prior to decoding. A count of saturated soft values in a code block is determined and one or more of the soft values in the code block are adjusted based on the count of saturated soft values. The count may be determined by incrementing the count for each positive saturated soft value and decrementing the count of each negative saturated soft value. The soft values may be adjusted by adding an offset computed based on the count to the soft values.

Abstract: A method is described for adjusting soft values in a code block prior to decoding. A count of saturated soft values in a code block is determined and one or more of the soft values in the code block are adjusted based on the count of saturated soft values. The count may be determined by incrementing the count for each positive saturated soft value and decrementing the count of each negative saturated soft value. The soft values may be adjusted by adding an offset computed based on the count to the soft values.

Abstract: Coded digital data symbols sent from a transmitter through a transmission channel of a communications network are received in a receiver. An estimate, represented by a first number of bits, of a sent data symbol is calculated, and a second number of bits, lower than the first number, is selected from the estimate to achieve a rounded estimate represented by the second number of bits. The rounded estimate is decoded to achieve a decoded data symbol. A target value for a block error rate of the transmission channel is received from the network; and the second number of bits is selected in dependence on the target block error rate value. Thus an optimal rounded estimate is provided in most situations, and the method can be performed with the limited computational resources of a terminal.

Abstract: A receiver utilizes pilot channel propagation channel estimates and a signal-to-interference metric derived from the pilot channel to form combining weights for use in obtaining soft symbols from a desired channel for subsequent decoding. The soft symbols thus obtained are substantially independent of the pilot channel amplitude.

Abstract: Methods and apparatus that do not require a memory between the combiner and decision boundary estimator in a digital communications receiver and that enjoy unaltered performance are described. The methods and apparatus include new ways of estimating bit decision boundaries and may also include new ways of estimating soft bit values.

Abstract: A method and a receiver for receiving coded digital data symbols sent from a transmitter through a transmission channel of a communications network is adapted to calculate first symbol estimates (y) of sent data symbols from the received data symbols, each of the first symbol estimates (y) having a first bitwidth (a+b), provide a scaling factor (s) and using the scaling factor (s) to scale the first symbol estimates, truncate the scaled symbol estimates (ysc) to a second, lower bitwidth (c) and thereby providing second symbol estimates (yt)

Abstract: Coded digital data symbols sent through a transmission channel of a communications network are received in a receiver. Estimates (y) represented by a first number (a+b) of bits are calculated, and modified estimates (y?) represented by a second number (c) of bits provided therefrom, the second number being lower than the first number. An amplitude value is calculated for each estimate (y), and an averaged amplitude value calculated for a number of amplitude values. A scaling factor (s) is calculated form the averaged amplitude value, and scaled estimates generated in dependence of die scaling factor. The scaling factor is used for a number of scaled estimates corresponding to the number of amplitude values for which the averaged amplitude value was calculated. Thus a better scaling factor is provided for most channel cases, which can still be calculated with the limited computational resources of a terminal for such networks.

Abstract: A method and system are described for performing fast and simple M-QAM detection on received signals, such as a 16-QAM signal, by estimating M-QAM symbol constellation decision boundaries. Amplitude information is collected for in-phase and quadrature phase components of the received signal over a number of symbols. An average of the absolute value of the amplitude information of the in-phase components and of the quadrature phase components is determined over the number of symbols. The determined average absolute values of the in-phase and quadrature phase components provide a reference to produce the decision boundary estimates. Bias compensation may optionally be applied to the decision boundary estimates based on the estimated signal-to-interference ratio (“SIR”) of the received signal to produce bias corrected decision boundary estimates.

Abstract: Coded digital data symbols sent from a transmitter through a transmission channel of a communications network are received in a receiver. An estimate, represented by a first number of bits, of a sent data symbol is calculated, and a second number of bits, lower than the first number, is selected from the estimate to achieve a rounded estimate represented by the second number of bits. The rounded estimate is decoded to achieve a decoded data symbol. A target value for a block error rate of the transmission channel is received from the network; and the second number of bits is selected in dependence on the target block error rate value. Thus an optimal rounded estimate is provided in most situations, and the method can be performed with the limited computational resources of a terminal.

Abstract: Methods and apparatus that do not require a memory between the combiner and decision boundary estimator in a digital communications receiver and that enjoy unaltered performance are described. The methods and apparatus include new ways of estimating bit decision boundaries and may also include new ways of estimating soft bit values.

Abstract: A method and system are described for performing fast and simple M-QAM detection on received signals, such as a 16-QAM signal, by estimating M-QAM symbol constellation decision boundaries. Amplitude information is collected for in-phase and quadrature phase components of the received signal over a number of symbols. An average of the absolute value of the amplitude information of the in-phase components and of the quadrature phase components is determined over the number of symbols. The determined average absolute values of the in-phase and quadrature phase components provide a reference to produce the decision boundary estimates. Bias compensation may optionally be applied to the decision boundary estimates based on the estimated signal-to-interference ratio (“SIR”) of the received signal to produce bias corrected decision boundary estimates.