Abstract: Techniques are provided to control the transmit power for data transmission on multiple transport channels having different signal quality (SIR) targets. A single SIR target is maintained for all transport channels, and this SIR target is adjusted based only on active transport channels. For each update interval, a data processor processes at least one data block received in the current update interval on at least one of the transport channels and provides the status of each received data block. A controller increases the SIR target based on an up step if any received data block is erased and decreases the SIR target based on a down step if all received data blocks are good. If any received data block is erased, the down step used to adjust the SIR target may be set to the smallest down step size required by all transport channels with erased data blocks.

Abstract: Techniques to improve the performance of a Turbo decoder when scale information for the bits in a code segment to be decoded is not known. A number of hypotheses are formed for the code segment, with each hypothesis corresponding to a particular set of one or more values for a set of one or more parameters used for decoding the code segment. For the MAP decoding scheme, these parameters may be for the sequence of scaling factors used to scale the bits prior to decoding and/or a scale used to evaluate a (e.g., min*) function for the MAP decoding. The code segment is decoded based on the MAP decoding scheme and in accordance with each hypothesis. The quality of the decoded result for each hypothesis is determined based on one or more performance metrics. The decoded bits for the best hypothesis are provided as the Turbo decoder output.

Abstract: Systems and techniques are disclosed relating to wireless communications. These systems and techniques involve wireless communications wherein a device may be configured to recover an information signal from a carrier using a reference signal, detect a frequency error in the information signal; and periodically tune the reference signal to reduce the frequency error.

Abstract: Techniques to efficiently generate memory addresses for a Turbo code interleaver using a number of look-up tables. An interleaver includes a storage unit, sets of tables, and an address generator. The storage unit stores K elements for a data packet at locations representative of an R×C array, with the elements being stored in a first (e.g., linear) order and provided in a second (e.g., interleaved) order. A first set of table(s) stores sequences (e.g., inter-row permutation sequences PA, PB, PC, and PD) used to perform row permutation of the array to map from the first order to the second order. A second set of table(s) stores sequences (e.g., intra-row base sequences and prime number sequences) used to perform column permutation. The address generator receives a first address for the first order and generates a corresponding second address for the second order based on sequences stored in the tables.

Abstract: Techniques for inter-frequency neighbor list searching are disclosed. Embodiments disclosed herein address the need for inter-frequency neighbor list searching. In one embodiment, a searcher is deployed to search a PN space with a first set of search parameters and to return search results. A subset of those results are selected, along with a previously saved search result, to form a set of PN locations for a second search. The second search is performed on a window around each of the PN locations, using a second set of search parameters. The maximum peak from the second search is saved for use in future iterations. In one embodiment, the subset is selected as the highest energy level peaks from the first search. In one embodiment, if a maximum peak is deemed to correspond to a valid base station when the position of that maximum peak is within a pre-determined time offset from a previous maximum peak.

Abstract: Techniques for processing symbols received for a (transport) channel in a (W-CDMA) communication system. According to the W-CDMA standard, the coded bits of a transport channel are first rate-matched, then first de-interleaved, and then segmented to form X radio frames, where X is the transmission time interval (TTI) of the transport channel. The radio frames can be processed in various manners. In one aspect, the rate-matching and first interleaving can be applied to the coded bits of the transport channel X times to generate a radio frame with each application. In accordance with a method, the correspondence between the coded bit xm and the rate-matched bits yn, and between the rate-matched bits yn and the interleaved bits zk, can be computed based on direct or iterative computations. In another aspects, the first de-interleaving and inverse rate-matching can be applied onto each rad it is received, without having to wait for the remaining radio frames in the TTI to be received.

Abstract: Techniques for predicting weights used for closed-loop transmit diversity. In a channel prediction scheme, channel gains for multiple transmit antennas are initially estimated (e.g., based on pilots received from these antennas) and used to derive predicted channel gains for a future time instant. The predicted channel gains are then used to derive predicted weights that are deemed to be “optimal” at the future time instant. Optimality may be determined based on one or more criteria, such as maximizing a received SNR for the received signals. In a weight prediction scheme, the channel gains for the multiple antennas are estimated and used to compute optimal weights for the current time instant. The current optimal weights are then used to predict the optimal weights at the future time instant. For both schemes, the prediction may be performed based on an adaptive filter (e.g., LMS or RLS filter) or a non-adaptive filter.

Abstract: Techniques for processing transmissions in a communications (e.g., CDMA) system. Samples are received and assembled into one or more traffics, with each traffic including one or more portions (e.g., radio frames, coded blocks) suitable for processing independently. The priority of each portion is determined based on its processing delays requirement, which can be estimated based on, for example, the time interval over which the samples in the traffic are interleaved, the processing deadline, and so on. A portion in a traffic having the highest priority is selected and scheduled for processing. The processing can include reordering the samples in the selected portion in accordance with a particular reordering scheme, accumulating redundant samples and inserting place holders (e.g., don't cares) for deleted samples in the selected portion, and decoding the reordered samples in the selected portion.

Abstract: Techniques for improved diversity pilot estimation in rapidly changing channel environments are disclosed. In one aspect, a difference estimate is updated when a current received symbol comprises a difference between the primary and diversity channels, and a sum estimate is updated when a current received symbol comprises a sum of the primary and diversity channels. The primary channel and the diversity channel are estimated in response to the sum estimate and the difference estimate. In another aspect, the sum estimate and difference estimate are produced by filtering the received symbols. In yet another aspect, received symbols are demodulated in response to the primary and diversity channel estimates. These aspects have the benefit of incorporating the most recently received symbol, resulting in more accurate channel estimates and hence improved demodulation performance, increased system capacity, lower required transmit power, and other benefits.

Abstract: Techniques to quickly adjust an SIR target toward a final value needed to achieve a specified target BLER for a data transmission. The outer loop may be implemented with multiple modes. The SIR target may be maintained fixed in a hold mode, adjusted in large down steps to speed up convergence in an acquisition mode, and adjusted by a small down step and a large up step for good and erased blocks, respectively, in a tracking mode. Various schemes may be used to adjust the SIR target by larger down steps in the acquisition mode. These schemes may be used even if data is transmitted intermittently, the target BLER is set to a low value, and/or one or multiple transport channels are used for data transmission. The SIR target may be boosted by a particular amount upon transitioning from the acquisition mode to the tracking mode.

Abstract: A method and apparatus for using information about a mobile terminal's location relative to a base station can improve performance of a communication system. In addition, information about the mobile terminal's velocity relative to the base station may be used to improve performance of the communication system. The location information may be used to estimate a nominal PN offset, and a set of PN offset to use, for processing communication signals. The velocity information may be used to estimate a nominal frequency of the communication signals.

Abstract: In a wireless communication system having a composite transport channel made up of individual transport channels, a method for closed loop power control wherein multiple instances of the outer loop are performed in parallel. The method determines a Signal-to-Interference Ratio (SIR) threshold for the composite channel based on a channel quality metric evaluated for each of the individual channels. In one embodiment the channel quality metric is a Cyclical Redundancy Check (CRC) outcome.

Abstract: Techniques for improved handoff searching in asynchronous systems, such as W-CDMA, are disclosed. In one aspect, a two-step search procedure is used when a list of neighbor codes is known. In the first step, a received signal is correlated with a slot timing code to locate on or more pilots and the slot boundaries associated therewith. In the second step, the received signal is correlated with each of the list of codes at the slot boundaries identified with pilots in the first step to identify the pilot code and the frame timing associated with each pilot. Various other aspects of the invention are also presented. These aspects have the benefit of decreasing search time, which translates to increased acquisition speed, higher quality signal transmission, increased data throughput, decreased power, and improved overall system capacity.

Abstract: Systems and techniques are disclosed relating to communications. The systems and techniques involve transmitting to a remote location a first signal at a first energy level followed by a second signal at a second energy level, determining a target transmission energy level as a function of a target quality parameter at the remote location, and computing the second energy level as a function of the target transmission energy level and the first energy level. It is emphasized that this abstract is provided solely to assist a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: Noise measurements are made within a fraction of a single symbol period of a longest orthogonal code symbol. A control processor identifies an unoccupied code having a spreading factor that is less than a longest spreading factor for the system. A despreader measures symbol energy based on the unoccupied code and a noise estimator generates noise estimations based on the measured symbol energies.

Abstract: Techniques for improved low latency frequency switching are disclosed. In one embodiment, a controller receives a frequency switch command and generates a frequency switch signal at a time determined in accordance with a system timer. In another embodiment, gain calibration is initiated subsequent to the frequency switch signal delayed by the expected frequency synthesizer settling time. In yet another embodiment, DC cancellation control and gain control are iterated to perform gain calibration, with signaling to control the iterations without need for processor intervention. Various other embodiments are also presented. Aspects of the embodiments disclosed may yield the benefit of reducing latency during frequency switching, allowing for increased measurements at alternate frequencies, reduced time spent on alternate frequencies, and the capacity and throughput improvements that follow from minimization of disruption of an active communication session and improved neighbor selection.

Abstract: A method and apparatus for determining an operational mode for use in a wireless communication system based on a location, a velocity, or both, of a wireless communication device (WCD) in relation to a wireless network infrastructure is described. The selected mode can be used by various devices within the communication system. Modes that are selected include transmit diversity and site selection diversity.

Abstract: Multiple access interference may be substantially removed by introducing a near-far situation in which a near mobile and a far mobile (“near” and “far” based on signal strength) are selected, resources allocated among these and other mobiles, and the data is packetized for transmission during a transmission interval such that the data intended for the far mobile is transmitted along with the data intended for the near mobile. Forward link signals are then appropriately scheduled. Signals intended for the far mobile and the near mobile are decoded from the composite signal received at the near mobile. The signal intended for the far mobile is then removed from the composite signal received at the near mobile.

Abstract: Techniques for improved diversity pilot estimation in rapidly changing channel environments are disclosed. In one aspect, a difference estimate is updated when a current received symbol comprises a difference between the primary and diversity channels, and a sum estimate is updated when a current received symbol comprises a sum of the primary and diversity channels. The primary channel and the diversity channel are estimated in response to the sum estimate and the difference estimate. In another aspect, the sum estimate and difference estimate are produced by filtering the received symbols. In yet another aspect, received symbols are demodulated in response to the primary and diversity channel estimates. These aspects have the benefit of incorporating the most recently received symbol, resulting in more accurate channel estimates and hence improved demodulation performance, increased system capacity, lower required transmit power, and other benefits.

Abstract: A receiver unit for use in a CDMA system and including a channel processor, a buffer, and a data processor. The channel processor processes samples for one or more physical channels for each time interval to provide symbols. The buffer is operated as a number of memory banks. Each memory bank is associated with a respective time interval and stores symbols associated with that time interval. The data processor retrieves symbols for a particular “traffic” from one or more memory banks and processes the retrieved symbols. For the W-CDMA system, each traffic includes one or more radio frames for a particular transmission time interval. The receiver unit typically further includes a controller that directs the storage and retrieval of symbols to and from the memory banks and a decoder that decodes symbols processed by the data processor.