Abstract: A method and apparatus for determining operating modes in a receiver is described herein. A delay searcher in the receiver detects a signal image in the received signal. When the receiver is a RAKE receiver, a plurality of RAKE fingers coherently combine time-shifted versions of the received signal at different delays. Alternatively, when the receiver is a chip equalization receiver, an FIR filter coherently pre-combines the signal images in the received signal. A processor determines delays. In particular, the processor generates a first signal quality metric for a single-delay receiver mode, and generates a second signal quality metric for a multi-delay receiver mode. Based on a comparison of the first and second signal quality metrics, the processor selects the single-delay or the multi-delay receiver mode for processing the signal image.

Abstract: A receiver and method for receiving and processing a sequence of transmitted symbols in a digital communication system utilizing soft pilot symbols. A set of soft pilot symbols are transmitted 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 receiver knows the modulation type and location (time/frequency/code) of the soft pilot symbols, and demodulates them first. The receiver uses the demodulated soft pilot symbols as known symbols to estimate parameters of the received radio signal. 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.

Abstract: A wireless communication receiver is configured to suppress interference with respect to a received signal of interest on a selective basis responsive to evaluating whether the receiver currently is or is not operating in a colored noise/interference environment. For example, an exemplary Code Division Multiple Access (CDMA) mobile station activates or deactivates interference suppression responsive to determining and evaluating an orthogonality factor, which, in this context, serves as a measure of how much downlink power gets converted into same-cell interference via multipath propagation. The orthogonality factor thus serves as an indicator of noise plus interference coloration. In one or more exemplary embodiments, then, an exemplary receiver circuit is configured to determine the orthogonality factor, evaluate it, and selectively enable or disable received signal whitening based on that evaluation.

Abstract: A multi-carrier linear equalization receiver, e.g., a RAKE receiver or chip equalization receiver, is described herein. The multi-carrier receiver distributes processing delays among a plurality of received carriers based on a dispersion determined for each carrier. The receiver initially allocates a minimum number of processing delays sufficient for light dispersion to each carrier. For the dispersive carriers, the receiver allocates one or more additional processing delays. In one embodiment, the additional processing delays are allocated to the dispersive carriers based on SIR.

Abstract: Channel estimation and/or equalization processing is performed in a wireless receiver in two stages. The first stage involves pre-filtering in the frequency domain to compact a grid-based representation of the net channel. The second stage involves implementing reduced-complexity time domain channel estimation and/or equalization. According to one embodiment, a received signal transmitted over a net channel is processed by pre-filtering the received signal in the frequency domain. The frequency domain pre-filtering compacts an N-tap effective grid-based representation of the net channel into a K-tap compacted grid-based representation of the net channel where K<N. The pre-filtered received signal is equalized in the time domain based on the K-tap compacted grid-based representation of the net channel generated by pre-filtering the received signal in the frequency domain.

Abstract: 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.

Abstract: A signal-to-interference estimate is generated using unknown data symbols in place of or in addition to pilot symbols. Data received over a data channel (traffic channel or control channel) are collected. The data symbols are then used to compute an observation metric based on deviations of the data symbols from a predetermined set of possible data symbols, wherein one of the data symbols and symbol constellation is normalized. A data channel signal-to-interference ratio is then computed based on the observation metric.

Abstract: A method of operating a User Equipment (UE) for generating a second scrambling code group where the UE is configured for receiving downlink transmission from a Universal Mobile Telecommunications System Terrestrial Radio Access Network (UTRAN) on a set of at least two downlink carriers including an anchor carrier and at least a first secondary carrier includes: determining a first scrambling code group associated with a first cell on the anchor carrier and deriving the second scrambling code group associated with a second cell on said first secondary carrier using a predefined rule defining the relation between the second scrambling code group and the first scrambling code group.

Abstract: A CDMA receiver computes an accurate estimate of the data to pilot power ratio. First, a biased estimate of the data to pilot power ratio is obtained from the data channel. A multiplicative correction factor is then computed from the pilot channel, and applied to the biased data to pilot power ratio estimate.

Abstract: The computation of code-specific channel matrices for an Assisted Maximum Likelihood Detection (AMLD) receiver comprises separately computing high rate matrices that change each symbol period, and a low rate matrix that is substantially constant over a plurality of symbol periods. The high and low rate matrices are combined to generate a code-specific channel matrix for each receiver stage. The high rate matrices include scrambling and spreading code information, and the low rate matrices include information on the net channel response and combining weights. The low rate matrices are efficiently computed by a linear convolution in the frequency domain of the net channel response and combining weights (with zero padding to avoid circular convolution), then transforming the convolution to the time domain and extracting matrix elements. Where the combining weights are constant across stages, a common code-specific channel matrix may be computed and used in multiple AMLD receiver stages.

Abstract: The technology comprises method(s) and apparatus for operating a telecommunications system. In its basic form the method comprises providing plural channelization codes for potential use by an uplink receiver; using unused channelization codes of the plural codes to generate an estimate of an impairment covariance matrix; and using the estimate of the impairment covariance matrix to form a processing parameter. For example, the processing parameter can be one or more weight values which, in turn, are can be used for generating a combined output signal.

Abstract: Adaptive reconfiguration of a wireless receiver is enabled based on channel geometry. According to an embodiment, the wireless receiver includes a geometry factor processing module and signal processing modules, e.g. such as but not limited to an SIR estimation module, a power estimation module, a despreading module, a low-pass filter, a combing weight generation module, a coefficient estimation module, a synchronization control channel interference canceller module, etc. The geometry factor processing module determines a geometry factor for the channel over which signals are transmitted to the wireless receiver, the geometry factor being a measure of the ratio of total transmitted power received by the wireless receiver to total interference plus noise power at the wireless receiver. One or more of the receiver signal processing modules are reconfigurable based on the geometry factor.

Abstract: A method and apparatus provide for setting processing delay assignments in a CDMA receiver using a flat-channel placement or using a dispersive channel placement, in dependence on characterizing the channel as flat or dispersive. For example, a receiver maintains a logical flag reliably indicating the current channel state as flat or dispersive, and assigns or otherwise sets processing delays—e.g., for received signal demodulation—using a flat-channel placement algorithm or a dispersive-channel placement algorithm. The “flat-channel” placement algorithm generally provides better performance in flat-channel environments, and the “dispersive-channel” placement algorithm generally provides better performance in dispersive channel environments. Such processing may be regarded as “activating” a simplified processing delay placement grid that offers better performance if the channel truly is flat, with the underlying advantage of providing a reliable mechanism for detecting flat channel conditions.

Abstract: A control system and method for controlling a spread spectrum receiver such as a generalized Rake (G-Rake) receiver or chip equalizer based on a frequency shift (fD) of a received signal. A hybrid channel estimator outputs a low-rate channel estimate such as a slot average channel estimate if fD is less than or equal to a threshold value. If fD is greater than the threshold, a plurality of high-rate channel estimates such as interpolated channel estimates is produced. An impairment covariance matrix estimates correlations between impairment on different fingers of the G-Rake receiver. The update rate of the matrix is controlled dependent on the value of fD. A combining weights calculator then calculates sets of combining weights based on the channel estimates and the impairment correlation estimates.

Abstract: A symbol detector converts initial symbol estimates of received symbols to soft estimates for decoding. The symbol detector computes spreading waveform correlations between a spreading waveform for a symbol of interest and spreading waveforms for one or more interfering symbols. Interference rejection terms are computed by scaling the spreading waveform correlations by corresponding signal powers and compensating for noise. A soft scaling factor for the symbol of interest is computed from the interference rejection terms. The soft scaling factors are then applied to the initial symbol estimates to generate the soft estimates.

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: Methods and devices are provided whereby scrambling codes can be set in an improved way. In accordance with one embodiment a method is provided in a User Equipment for generating a second scrambling code or a second scrambling code group. The UE is configured for multi carrier operation receiving downlink transmission from a Universal Mobile Telecommunications System Terrestrial Radio Access Network on a set of at least two downlink carriers including an anchor carrier and at least a first secondary carrier. The method comprises determining a first scrambling code or a first scrambling code group associated with a first cell on the anchor carrier; and deriving a second scrambling code or a second scrambling code group associated with a second cell on said first secondary carrier using a predefined rule defining the relation between the second scrambling code or second scrambling code group and the first scrambling code or scrambling code group.

Abstract: Path delay information generated by a path searcher module of a wireless receiver is used to generate net channel coefficients for use in suppressing interference from a received signal. According to one embodiment, interference is suppressed from a signal transmitted over a communication channel including transmit and receive pulse shaping filters and a radio channel by generating net channel coefficients for the communication channel at processing delays such as G-Rake finger delays or chip equalizer tap delays. Medium channel coefficients are generated for the radio channel at estimated path delays as a function of the net channel coefficients. The net channel coefficients are regenerated at arbitrary delays as a function of the medium channel coefficients and an impairment covariance estimate is generated based at least in part on the regenerated net channel coefficients.

Abstract: A receiver and method for receiving and processing a sequence of transmitted symbols in a digital communication system utilizing soft pilot symbols. A set of soft pilot symbols are transmitted 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 receiver knows the modulation type and location (time/frequency/code) of the soft pilot symbols, and demodulates them first. The receiver uses the demodulated soft pilot symbols as known symbols to estimate parameters of the received radio signal. 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.

Abstract: A method and apparatus for controlling the transmit power of a mobile device in a mobile communication network takes the level of self-interference into account to perform inner-loop power control. For normal inner-loop power control, a signal quality estimate is compared to a signal quality target and power control commands are generated based on the comparison. When self-interference is the dominant impairment in the received signal, a “fast break” is introduced to change inner-loop power control command generation. The amount of self-interference is determined based on the delay spread of the channel.