Patent application number | Description | Published |
20100046682 | ENHANCED GERAN RECEIVER USING CHANNEL INPUT BEAMFORMING - A method for suppressing interference in a wireless communication is provided. The method comprises receiving a burst of symbols, generating a plurality of timing hypotheses for the burst of symbols, and calculating, for each timing hypothesis, a plurality of weights for an interference suppression filter based upon a subset of the burst of symbols. The method further comprises, for each timing hypothesis, filtering the subset of the burst of symbols using the interference suppression filter with the corresponding plurality of weights, and selecting one of the plurality of timing hypotheses corresponding to a selection criteria. The method further comprises equalizing and decoding the filtered burst of symbols based upon the selected one of the plurality of timing hypotheses. | 02-25-2010 |
20100158170 | METHODS AND SYSTEMS USING FFT WINDOW TRACKING ALGORITHM - Techniques for the adjustment of a position of Fast Fourier Transform (FFT) window are provided. The adjustment may be based on the condition that the length of channel impulse response is larger than the length of cyclic prefix. The technique may determine a position of the FFT window that attempts to maximize carrier-to-noise (C/N) ratio value measured at the receiver. | 06-24-2010 |
20100278217 | METHOD AND SYSTEM FOR MULTI-USER DETECTION USING TWO-STAGE PROCESSING - Systems and methods for multi-user detection are provided. In one aspect of the disclosure, an apparatus is provided. The apparatus comprises a processing unit configured to process a plurality of received chips into a plurality of received symbols for a plurality of users. The apparatus further comprises a computation unit configured to compute a multi-user matrix relating a plurality of user symbols for the plurality of users to the plurality of received symbols and a detection unit configured to detect the plurality of user symbols for the plurality of users using the computed multi-user matrix and the plurality of received symbols. | 11-04-2010 |
20100278218 | METHOD AND SYSTEM FOR MULTI-USER INTERFERENCE CANCELLATION - Systems and methods for multi-user interference cancellation are provided. In one aspect of the disclosure, an apparatus is provided. The apparatus comprises a processing unit configured to process received chips into received symbols for a plurality of users and a detection unit configured to detect user symbols from the received symbols. The apparatus also comprises an interference cancellation unit configured to compute multi-user interference using the detected user symbols and to remove the computed multi-user interference from the received symbols. The apparatus further comprises a redetection unit configured to redetect user symbols from the received symbols with the computed multi-user interference removed. | 11-04-2010 |
20110064066 | Methods for Estimation and Interference Cancellation for signal processing - A receiver in a CDMA system comprises a front end processor that generates a combined signal per source. A symbol estimator processes the combined signal to produce symbol estimates. An S-Matrix Generation module refines these symbol estimates based on the sub channel symbol estimates. An interference canceller is configured for cancelling interference from at least one of the plurality of received signals for producing at least one interference-cancelled signal. | 03-17-2011 |
20110292974 | Methods for estimation and interference suppression for signal processing - A receiver in a CDMA system comprises a front end processor that generates a combined signal per source. A symbol estimator processes the combined signal to produce symbol estimates. An S-Matrix Generation module refines these symbol estimates based on the sub channel symbol estimates. An interference canceller is configured for cancelling interference from at least one of the plurality of received signals for producing at least one interference-cancelled signal. | 12-01-2011 |
Patent application number | Description | Published |
20100195518 | SMOOTH EDGE DISTORTION IN BROADBAND CHANNEL INTERPOLATION VIA VIRTUAL PILOT EXTRAPOLATION - In the basic transform domain (linear filtering interpolation) technique for channel estimation at the receiver in a wireless communication system, the improvement of providing channel estimation at the receiver with computational efficiency, comprising:
| 08-05-2010 |
20100202571 | METHODS AND SYSTEMS FOR FREQUENCY DOMAIN GAIN CONTROL IN OFDM MIMO SYSTEMS - Certain embodiments of the present disclosure provide a method for frequency-domain gain control in system utilizing orthogonal frequency division multiplexing (OFDM) multiple input multiple output (MIMO). The proposed method reduces the complexity of the system while maximizing the internal accuracy of the OFDM MIMO decoder and preserving the performance of the system. | 08-12-2010 |
20110149943 | TIME TRACKING LOOPS FOR A COMMUNICATION SYSTEM UTILIZING A CYCLIC PREFIX - Techniques for performing time tracking in a communication system utilizing a cyclic prefix are described. In an aspect, a receiver may detect for large timing errors based on early and late received samples obtained with early and late FFT windows, respectively. The receiver may derive first and second channel impulse response (CIR) estimates based on the early and late received samples, respectively, determine an early channel energy based on the first CIR estimate, determine a late channel energy based on the second CIR estimate, compute an update amount based on the early and late channel energies, and update the FFT window position based on the update amount. In another aspect, the receiver may perform time tracking with an inner time tracking loop (TTL) and an outer TTL. The receiver may update the FFT window position in coarse steps with the outer TTL and in fine steps with the inner TTL. | 06-23-2011 |
20110158342 | TIME TRACKING FOR A COMMUNICATION SYSTEM UTILIZING A CYCLIC PREFIX - Techniques for performing time tracking in a communication system utilizing a cyclic prefix are described. In an aspect, a receiver may perform time tracking and determine an FFT window position based on a metric related to inter-symbol interference (ISI) and inter-carrier interference (ICI). The receiver may determine an early energy for signal paths earlier than the current FFT window position, determine a late energy for signal paths later than the current FFT window position, determine the metric based on the early and late energies, compute an update amount for the FFT window position based on the metric, and update the FFT window position based on the update amount with a time tracking loop (TTL). In yet another aspect, the receiver may compute the FFT window position based on a channel impulse response (CIR) estimate directly, without using a TTL. | 06-30-2011 |
20110206151 | MULTI-TERM DEMAPPING FOR MULTI-CHANNEL WIRELESS COMMUNICATION - Providing for reduced complexity or improved accuracy in de-mapping received wireless data streams for multi-channel wireless communication is described herein. By way of example, a low-complexity likelihood algorithm can be employed to de-map data bits from the wireless data streams. In one particular example, the likelihood algorithm can approximate a received bit with a subset of received wireless symbols correlated the bit, reducing algorithm complexity. In other examples, a limited set of received wireless symbols can be employed for the subset, further reducing algorithm complexity. According to at least one other example, logarithmic terms of the algorithm can be approximated with non-logarithmic functions, such as a look-up table, series expansion, polynomial approximation, or the like. These approximations can enhance symbol de-mapping accuracy while maintaining or improving processing overhead for a wireless receiver. | 08-25-2011 |
20110211470 | INTERFERENCE REJECTION BY SOFT-WINDOWING CIR ESTIMATES BASED ON PER-TAP QUALITY ESTIMATES - A channel impulse response (CIR) estimate associated with a communication channel may be processed by determining coefficient values that respectively correspond to taps of the CIR estimate, and multiplying the taps by the respectively corresponding coefficient values. The coefficient values are determined according to a soft decision technique. The resulting modified CIR estimate is used to demodulate a communication signal received via the communication channel. | 09-01-2011 |
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 |
20120176922 | DOWNLINK FLOW CONTROL BY ADDING NOISE TO A RECEIVER TO REDUCE PHYSICAL LAYER THROUGHPUT - Aspects of the present disclosure relate to wireless communications and techniques and apparatus for downlink flow control at the physical layer of a user equipment (UE). Aspects generally include monitoring one or more parameters related to the UE and intentionally reducing channel quality based on the one or more parameters to trigger downlink flow control. According to aspects, channel quality may be reduced by degrading receiver performance and/or intentionally adding noise to a signal. | 07-12-2012 |
20120219097 | TWO-STEP JOINT DEMAPPING ALGORITHM FOR LLR COMPUTATION OF MIMO SIGNAL BASED ON SPHERE DECODING - Certain aspects of the present disclosure relate to a technique for two-step joint demapping based on sphere decoding for log-likelihood ratio (LLR) computation related to a received multiple-input multiple-output (MIMO) signal. The first step of the proposed algorithm comprises a linear minimum mean square error (LMMSE) based detection to form soft symbol estimates of symbols being transmitted. Then, the LMMSE-based soft symbol estimates can be utilized to form a set of constellation points of a stream interfering to a stream of interest. These candidate constellation points can be then subtracted (canceled) from the received signal to improve the LLR computations of the stream of interest. After the cancellation, the maximum ratio combining (MRC) can be applied to each individual stream to form more refined soft symbol estimates as well as an effective signal-to-noise ratio (SNR) estimate. The refined outputs of the MRC can be utilized to compute LLRs of transmitted bits based on the effective SNR and the refined soft symbol estimates associated with all the candidate constellation points from the set. The LLRs of transmitted bits may be employed by a channel decoder. | 08-30-2012 |
20130235818 | Channel Estimation in Wireless Networks - Aspects of the present disclosure generally relate to wireless communications and, more particularly, to performing channel estimation with modifications for improved system performance. Aspects generally include receiving, at a user equipment (UE), reference signals from a base station in a current subframe, and performing channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a mobility characteristic of the UE, and a configuration of subframes prior to the current subframe. | 09-12-2013 |
20130343267 | METHODS AND APPARATUSES FOR FLASH WCDMA FREQUENCY SCANS - A method and apparatus of wireless communication are configured to capture, at a user equipment, one or more adjacent Universal Mobile Telecommunication System Terrestrial Radio Access Absolute Radio Frequency Channel Numbers (UARFCNs), extract a useful wide band signal from the one or more adjacent UARFCNs, perform a PSCH search on the useful wide band signal to obtain a composite PSCH signal, and reject the one or more UARFCNs where no peaks greater than a noise threshold are detected in the composite PSCH signal. | 12-26-2013 |
20140200685 | THERMAL MITIGATION IN DUAL SIM DUAL ACTIVE DEVICES - A system, a method and an apparatus are described. The apparatus includes a modem that responds to a thermal mitigation request by invoking different levels of thermal mitigation for different concurrently active connections. In some instances, the modem may invoke thermal mitigation with respect to a first active connection and refrain from invoking thermal mitigation with respect to a second active connection maintained by the modem. The apparatus determines the first and second active connections based on subscriptions corresponding to subscriber identification modules, an identification of a power amplifier or group of power amplifiers responsible for a thermal issue in the modem. The selection of mitigation levels for each active connection and decisions to invoke mitigation on one connection while refraining from invoking mitigation on another connection may be based on priorities of the active connections, including quality of service related priorities. | 07-17-2014 |
20140213210 | Method of Robust Receive (Rx) Processing for Radio Frequency Coexistence Management in Dual-SIM-Dual-Active Communication Devices - The various embodiments include a dual-SIM-dual-active (DSDA) device and methods for implementing robust receive (Rx) processing to resolve radio frequency coexistence interference between two subscriptions operating on the DSDA device. The DSDA device may detect when a subscription (the “aggressor”) de-senses the other subscription (the “victim”) as a result of the aggressor's transmissions, and in response, implement robust Rx processing to mitigate the effects of de-sense on the victim while causing minimal impact to the aggressor. | 07-31-2014 |
20140213235 | Method of Robust Transmit (Tx) Processing for Radio Frequency Coexistence Management in Dual-SIM-Dual-Active communication Devices - The various embodiments include a dual-SIM-dual-active (DSDA) device and methods for implementing robust transmit (Tx) processing to resolve radio frequency coexistence interference between two subscriptions operating on the DSDA device. The DSDA device may detect when one subscription (the “aggressor”) de-senses the other subscription (the “victim”) as a result of the aggressor's transmissions, and in response, implement robust Tx processing to mitigate the effects of de-sense on the victim. | 07-31-2014 |
Patent application number | Description | Published |
20130254579 | SYSTEM AND METHOD FOR MANAGING ELECTRICAL CURRENT IN A PORTABLE COMPUTING DEVICE - A method and system for managing electrical current within a portable computing device (“PCD”) includes assigning a priority to two or more communications supported by the PCD. A present level of a power supply for the PCD may be monitored by a communications power (“CP”) manager module. Next, the CP manager module may determine if the two or more communications may be transmitted at the present level of the power supply. If the two or more communications cannot be transmitted at the present level of the power supply, then the CP manager module may determine if a timing of at least one of the communications may be adjusted. The CP manager module may also determine a theoretical power level adjustment for at least one of the communications. The two or more communications may be transmitted with any calculated timing off sets and power level adjustments. | 09-26-2013 |
20140006911 | METHODS AND APPARATUS FOR TURBO DECODER THROTTLING | 01-02-2014 |
20140241269 | METHODS AND APPARATUS FOR CONDITIONAL OFFLOAD OF ONE OR MORE LOG-LIKELIHOOD RATIOS (LLRS) OR DECODED BITS - Techniques and apparatus are provided for conditional offload of one or more LLRs or decoded bits. An exemplary electronic device (ED) method includes receiving a transmission of a physical downlink shared channel (PDSCH) having a transport block (TB) comprising at least one code block (CB), performing a cyclic redundancy check (CRC) of the at least one CB, in a memory external to a modem core of the ED, storing a subset of log-likelihood ratios (LLRs) associated with the at least one CB if the at least one CB failed the CRC or decoded bits associated with the at least one CB if the at least one CB passed the CRC, wherein the subset is based on an LLR range of the transmission relative to an LLR range of one or more previous transmissions, and using the stored subset of LLRs or decoded bits to process a re-transmission of the PDSCH. | 08-28-2014 |
20140269627 | METHOD AND APPARATUS FOR SHARING DECODING TIME ACROSS TRANSPORT BLOCKS - Techniques for efficiently decoding data at a receiver are disclosed. In one aspect, total available decoding time of the receiver is initially allocated to a plurality of code blocks of a plurality of transport blocks to obtain initial allocated decoding times for the plurality of code blocks. The initial allocated decoding time for each code block may be given by a particular number of decoding iterations to perform for that code block. One or more code blocks of one or more transport blocks are decoded. After decoding the one or more code blocks, a remaining available decoding time is determined and reallocated to undecoded code blocks of the plurality of transport blocks to obtain updated allocated decoding times for the undecoded code blocks. The remaining available decoding time may be reallocated across code blocks of a transport block, across transport blocks, across carriers, across radio access technologies, or a combination thereof. | 09-18-2014 |
20140301298 | METHODS AND APPARATUS FOR TRANSMISSION RESTRICTION AND EFFICIENT SIGNALING - Certain aspects of the present disclosure relate to methods and apparatus for transmission restriction and efficient signaling. A base station (BS) may determine information regarding a restricted set of system parameters used for transmission from at least one of the serving BS or one or more potentially interfering BSs and signal the information to a user equipment (UE). According to certain aspects, a UE may receive the signaling of information regarding the restricted set of system parameters used for transmission from at least one of the serving BS or the one or more potentially interfering BSs and use the information to cancel interference by transmissions from the one or more potentially interfering BSs or serving BS. | 10-09-2014 |