Patent application number | Description | Published |
20080233995 | POWER CONTROL FOR A CHANNEL WITH MULTIPLE FORMATS IN A COMMUNICATION SYSTEM - Techniques to more efficiently control the transmit power for a data transmission that uses a number of formats (e.g., rates, transport formats). Different formats for a given data channel (e.g., transport channel) may require different target SNIRs to achieved a particular BLER. In one aspect, individual target BLER may be specified for each format of each data channel. In another aspect, various power control schemes are provided to achieve different target SNIRs for different formats. In a first power control scheme, multiple individual outer loops are maintained for multiple formats. For each format, its associated outer loop attempts to set the target SNIR such that the target BLER specified for that format is achieved. In a second power control scheme, multiple individual outer loops are maintained and the base station further applies different adjustments to the transmit power levels for different formats. | 09-25-2008 |
20080253487 | ADAPTIVE PILOT AND DATA SYMBOL ESTIMATION - Techniques for performing adaptive channel estimation are described. A receiver derives channel estimates for a wireless channel based on received pilot symbols and at least one estimation parameter. The receiver updates the at least one estimation parameter based on the received pilot symbols. The at least one estimation parameter may be for an innovations representation model of the wireless channel and may be updated based on a cost function with costs defined by prediction errors. In one design, the receiver derives predicted pilot symbols based on the received pilot symbols and the at least one estimation parameter, determines prediction errors based on the received pilot symbols and the predicted pilot symbols, and further derives error gradients based on the prediction errors. The receiver then updates the at least one estimation parameter based on the error gradients and the prediction errors, e.g., if a stability test is satisfied. | 10-16-2008 |
20080310321 | METHOD AND APPARATUS FOR TIME-ALIGNING TRANSMISSIONS FROM MULTIPLE BASE STATIONS IN A CDMA COMMUNICATION SYSTEM - Schemes to time-align transmissions from multiple base stations to a terminal. To achieve time-alignment, differences between the arrival times of transmissions from the base stations, as observed at the terminal, are determined and provided to the system and used to adjust the timing at the base stations such that terminal-specific radio frames arrive at the terminal within a particular time window. In one scheme, a time difference between two base stations is partitioned into a frame-level time difference and a chip-level time difference. Whenever requested to perform and report time difference measurements, the terminal measures the chip-level timing for each candidate base station relative to a reference base station. Additionally, the terminal also measures the frame-level timing and includes this information in the time difference measurement only if required. Otherwise, the terminal sets the frame-level part to a predetermined value (e.g., zero). | 12-18-2008 |
20090041162 | SEARCHER FOR MULTIPLE ORTHOGONAL CHANNELS WITH KNOWN DATA WCDMA STEP2 SEARCH - A circuit and algorithm are disclosed for a step2 search of a three step search of synchronization channels in a W-CDMA system. A mobile terminal of the CDMA system includes an RF downconverter for receiving I and Q signals. A searcher, responsive to the I and Q signals, includes a first correlator for correlating the I and Q signals with a primary synchronization code on a primary synchronization channel, and a second correlator for correlating I and Q signals with a secondary synchronization code on a secondary synchronization channel. The correlated I and Q signals are added for each of the secondary synchronization codes. An energy calculator and a maximum energy detector use the correlated I and Q signals of both the primary and secondary synchronization channels to detect the most likely scrambling code group of secondary synchronization codes. | 02-12-2009 |
20090316842 | PHASE-NOISE RESILIENT GENERATION OF A CHANNEL QUALITY INDICATOR - System(s) and method(s) are provided for generating phase-noise resilient channel quality indicator(s). A pilot signal utilized to determine a channel quality indicator is rotated to be aligned to a phase reference signal. Separate noise evaluations in quadrature and in-phase directions are utilized, at least in part, to generate a net noise estimate that is phase-noise compensated or resilient. For example, various combination schemes of quadrature and in-phase noise evaluations can be exploited to generate a net noise estimate, the schemes include weighted average of in-phase and quadrature noise estimates and running averages thereof. Simulation of net noise estimates as a function of geometry conditions reveal that the combination schemes provide substantive mitigation of phase-noise, thus making CQI generation phase-noise resilient. | 12-24-2009 |
20090325586 | METHODS AND APPARATUS FOR COMMON CHANNEL CANCELLATION IN WIRELESS COMMUNICATIONS - A mobile station that is configured to perform common channel cancellation may include a parameter estimation unit that is configured to estimate parameters for generating a common channel error. The mobile station may also include a common channel generation unit that is configured to generate the common channel error based on the parameters. The mobile station may also include an adder that is configured to subtract the common channel error from received data samples. | 12-31-2009 |
20100002614 | LOW POWER MODES FOR FEMTO CELLS - Devices and methods are provided for deploying and/or implementing a low power mode in an access point (AP) base station. The low power mode may be implemented based on the presence and/or status of access terminals (ATs). In one embodiment, the method may involve determining whether any ATs are present within at least one defined coverage area. In another embodiment, the method may involve determining whether the ATs are in an idle or active state. | 01-07-2010 |
20100067396 | OPTIMIZING THROUGHPUT IN A WIRELESS COMMUNICATION SYSTEM - A method for optimizing throughput in a wireless communication system is disclosed. A target metric is estimated based on previous acknowledgment data. A channel quality indicator offset is determined based on the target metric. A channel quality indicator is adjusted based on the channel quality indicator offset. The channel quality indicator indicates the quality of a wireless transmission channel. | 03-18-2010 |
20100085913 | SYSTEM ACQUISITION WITH INTERFERENCE CANCELLATION IN THE PRESENCE OF FEMTOCELLS - Systems and methodologies are described that facilitate acquisition of a cell in the presence of interfering cells. An undesired cell in close proximity to a user equipment unit (UE) can inhibit detection of a desired cell. For instance, a femto cell near the UE can interfere with detection and acquisition of a macro cell. The UE can detect the undesired cell and reconstruct an estimate of signals transmitted by the undesired cell. The estimate can be employed to cancel interference from received signals to facilitate acquisition of a desired cell. | 04-08-2010 |
20100135172 | METHOD AND APPARATUS FOR PREDICTING CHANNEL QUALITY INDICATOR IN A HIGH SPEED DOWNLINK PACKET ACCESS SYSTEM - Various embodiments are disclosed which predict the channel quality indicator (CQI) in High Speed Downlink Packet Access (HSDPA). The accuracy of CQI is crucial for HSDPA performance. In some HSDPA systems the CQI may be as much as three (3) subframes stale. Accordingly, the prediction of CQI values is required in order to efficiently schedule data for transmission over the communication channel. Various embodiments disclose first order adaptive IIR filters which are significantly less complex than the finite impulse response (FIR) counterparts and achieve similar accuracy. By minimizing the mean squared error (MSE), an exact gradient descent algorithm may be used as well as two embodiment pseudolinear regression algorithms. | 06-03-2010 |
20100184455 | METHOD AND APPARATUS OPTIMIZING RECEIPT OF CALL/BROADCAST PAGING MESSAGES BY SELF-POWERED WIRELESS COMMUNICATIONS DEVICES - A wireless communications network ( | 07-22-2010 |
20100232397 | Method and Apparatus for Improved Cell Acquisition with Reduced Frequency Error Impact - A method and apparatus for improved initial cell acquisition with reduced frequency error impact. The method determines the slot timing of a transmission, identifies the primary scrambling code and frame timing using the common pilot channel, and provides a path profile using a pseudorandom noise (PN) search. An apparatus using a cell searcher that performs the method is also described. | 09-16-2010 |
20100304761 | SENSOR USES IN COMMUNICATION SYSTEMS - Methods and apparatus are directed to mobile devices utilizing motion and/or position sensors for improving operating performance and/or power efficiency. In one example, a method for reducing power consumption in a mobile device includes receiving movement information, establishing movement data based on the movement information, determining if the mobile device is stationary using the movement data; and reducing the frequency of searching for a base station when the mobile device is stationary. In another example, a mobile device which reduces power consumption based upon movement data includes an RF front end, a receiver coupled to the RF front end, a data demodulator coupled to the receiver, a searcher, coupled to the RF front end and the receiver, which searches for base stations, and a processing unit coupled to the searcher, wherein the processing unit controls the searcher based upon the stationarity of the mobile device. | 12-02-2010 |
20110051831 | UNIFIED ITERATIVE DECODING ARCHITECTURE USING JOINT LLR EXTRACTION AND A PRIORI PROBABILITY - Certain aspects of the present disclosure relate to a method and an apparatus for unified iterative demodulation-decoding that can be employed in both multiple-input multiple-output (MIMO) and non-MIMO wireless systems. | 03-03-2011 |
20110051860 | ITERATIVE DECODING ARCHITECTURE WITH HARQ COMBINING AND SOFT DECISION DIRECTED CHANNEL ESTIMATION - Certain aspects of the present disclosure relate to a method for iterative decoding with re-transmissions of data and to a method for iterative decoding with soft decision directed channel estimation. | 03-03-2011 |
20110090946 | EQUALIZER IN A WIRELESS COMMUNICATION SYSTEM - Techniques for performing equalization at a receiver are described. In an aspect, equalization is performed by sub-sampling an over-sampled input signal to obtain multiple sub-sampled signals. An over-sampled channel impulse response estimate is derived and sub-sampled to obtain multiple sub-sampled channel impulse response estimates. At least one set of equalizer coefficients is derived based on at least one sub-sampled channel impulse response estimate. At least one sub-sampled signal is filtered with the at least one set of equalizer coefficients to obtain at least one output signal. One sub-sampled signal (e.g., with largest energy) may be selected and equalized based on a set of equalizer coefficients derived from an associated sub-sampled channel impulse response estimate. Alternatively, the multiple sub-sampled signals may be equalized based on multiple sets of equalizer coefficients, which may be derived separately or jointly. The equalizer coefficients may be derived in the time domain or frequency domain | 04-21-2011 |
20110165907 | APPARATUS, SYSTEM, AND METHOD FOR MANAGING TRANSMISSION POWER IN A WIRELESS COMMUNICATION SYSTEM - An apparatus, system, and method efficiently manage transmission power in a user equipment (UE) device by maintaining and applying an authorized power level to determine a transmission power level after a power limited transmission and before a new power control command has been received. The UE device maintains the authorized power level by monitoring and adjusting the authorized power level based on received power control commands. After a power limited transmission where the maximum power level is less than the authorized power level, the UE device determines the transmission power level for the next transmission based on the authorized power level. Accordingly, after the power limiting situation has ceased, the UE device transmits at the optimum power level eliminating the inefficiencies of transmitting at a lower than authorized power before the next power control command is received. | 07-07-2011 |
20110208984 | PROTOCOL STACK POWER OPTIMIZATION FOR WIRELESS COMMUNICATIONS DEVICES - User experiences on wireless devices are affected by communication, computation, and user interface capabilities. Another key performance indicator of a wireless device is its battery life. A method, algorithm and apparatus for improving the communication, computation and user interface capabilities of a mobile device is disclosed, which requires the expenditure of less energy and increases battery life. The trade-off between battery life and user experience related to the communication capability is managed by a protocol stack power optimization algorithm that optimally allocates energy resources. The power management algorithm inputs and combines measurements made at various layers of the protocol stack to selectively control a set of actions impacting energy usage. The algorithm maps from a set of measurements to a set of actions that provides the best trade-off between user experience and energy consumption. | 08-25-2011 |
20110306315 | Quick Detection of signaling in a Wireless Communication System - Quick frequency tracking (QFT), quick time tracking (QTT), and non-causal pilot filtering (NCP) are used to detect sporadically transmitted signaling, e.g., paging indicators. For QFT, multiple hypothesized frequency errors are applied to an input signal to obtain multiple rotated signals. The energies of the rotated signals are computed. The hypothesized frequency error with the largest energy is provided as a frequency error estimate. For QTT, coherent accumulation is performed on the input signal for a first set of time offsets, e.g., early, on-time, and late. Interpolation, energy computation, and non-coherent accumulation are then performed to obtain a timing error estimate with higher time resolution. For NCP, pilot symbols are filtered with a non-causal filter to obtain pilot estimates for one antenna for non-STTD and for two antennas for STTD. The frequency and timing error estimates and the pilot estimates are used to detect the signaling. | 12-15-2011 |
20120045024 | METHODS AND APPARATUS FOR ITERATIVE DECODING IN MULTIPLE-INPUT-MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEMS - Methods and apparatus for receiving, processing, and decoding MIMO transmissions in communications systems are described. A non-Gaussian approximation method for simplifying processing complexity where summations are used is described. Use of a priori information to facilitate determination of log likelihood ratios (LLRs) in receivers using iterative decoders is further described. A Gaussian or non-Gaussian approximation method using a priori information may be used to determine a K-best list of values for summation to generate an LLR is also described. | 02-23-2012 |
20120142276 | METHOD AND APPARATUS FOR DATA AIDED CHANNEL QUALITY ESTIMATION - Methods and apparatuses for data aided channel quality estimation using both pilot and data information are disclosed herein. In one exemplary aspect, a method for estimating channel quality in a wireless communication system is disclosed. The method comprises estimating a pilot noise variance based on a pilot signal received from a base station on a downlink and estimating a data noise variance based on a data signal received from the base station on the downlink. The method also comprises combining the pilot noise variance and the data noise variance to obtain a combined noise variance, and estimating the channel quality based on the combined noise variance. | 06-07-2012 |
20120149402 | METHOD AND APPARATUS OPTIMIZING RECEIPT OF CALL/BROADCAST PAGING MESSAGES BY SELF-POWERED WIRELESS COMMUNICATIONS DEVICES - A wireless communications network ( | 06-14-2012 |
20120149403 | METHOD AND APPARATUS OPTIMIZING RECEIPT OF CALL/BROADCAST PAGING MESSAGES BY SELF-POWERED WIRELESS COMMUNICATIONS DEVICES - A wireless communications network ( | 06-14-2012 |
20120294275 | INFRASTRUCTURE-UNASSISTED INTER-DEVICE WIRELESS WIDE AREA NETWORK HANDOFF - Aspects describe infrastructure unassisted inter-device handoff. A method performed by a wireless communications apparatus for inter-device handoff is disclosed. A wireless communications apparatus that performs a network unassisted inter-device handoff is disclosed. A computer program product comprising a computer-readable medium that includes codes for carrying out inter-device handoff is disclosed. At least one processor configured to perform a network unassisted communication handoff is disclosed. | 11-22-2012 |
20130070869 | CHANNEL IMPULSE RESPONSE ESTIMATION FOR WIRELESS RECEIVER - Estimating a channel impulse response (CIR) for a wireless transmission, for example a multimedia broadcast multicast services single frequency network (MBSFN) transmission, may be performed by a receiver of an wireless subframe, without requiring operational memory in excess of what is needed for CIR estimation of unicast signaling, while providing enhanced delay spread coverage. The wireless subframe may be a MBSFN subframe. The receiver may form an aggregate vector of pilot tones extracted from an OFDM reference symbol of an wireless subframe. The receiver may subsample the aggregate vector to obtain a plurality of sub-vectors each comprising a distinct subsampling phase. The receiver may process the plurality of sub-vectors using an inverse fast Fourier transform to obtain time domain representations of each of the sub-vectors. The receiver may combine the time domain representations in various ways to obtain a CIR estimate for the wireless subframe. | 03-21-2013 |
20130208609 | REDUCING NETWORK ACQUISITION TIME - A method, an apparatus, and a computer program product for wireless communication are provided in which PAPR for an input of an AGC in a wireless receiver is generated. The AGC may provide a gain-controlled signal to a correlator when the PAPR of the input does not exceed the threshold ratio and may clamp the gain of the gain-controlled signal when PAPR of the input is large. A large PAPR may cause termination of search for a signal of interest in a current channel. The search may be resumed in a non-adjacent channel. | 08-15-2013 |
20140006908 | INTERPROCESSOR COMMUNICATIONS SYSTEMS AND METHODS | 01-02-2014 |