Patent application number | Description | Published |
20080285641 | SLICER INPUT AND FEEDBACK FILTER CONTENTS FOR BLOCK CODED DIGITAL COMMUNICATIONS - Improved decision directed adaptation and decision feedback equalizers are provided in a block coded digital communication system. The performance of a receiver is significantly improved by allowing the decision feedback equalizer to perform time-tracking and residual frequency offset compensation during the data portion of a frame. This is accomplished by capitalizing on the inherent correlation among the chips of a code word in a block coded digital communication system to identify certain instances where more reliable symbol estimates can be derived from a sliced chip without introduction the delay inherent in decoding. As the more reliable symbol estimates are fed back into the chip slicer, the total efficiency of the decision feedback equalizer is improved and the more reliable symbol estimates can be used to replace older content in the feedback filter to further improve the accuracy of the modified slicer input and further decrease the effects of error propagation by the decision feedback equalizer. | 11-20-2008 |
20100034146 | METHOD AND APPARATUS FOR SUPPORTING MULTI-USER AND SINGLE-USER MIMO IN A WIRELESS COMMUNICATION SYSTEM - Techniques for supporting distributed multiple-input multiple-output (MIMO) transmissions are described. In one design, a user equipment (UE) determines channel estimates for multiple cells and reports the channel estimates. The UE thereafter receives a data transmission sent by the multiple cells to the UE based on the channel estimates. The data transmission may include at least one data stream, and each data stream may be sent by one cell or the multiple cells to the UE. In another design, a UE determines first and second channel estimates for first and second cells, respectively, and reports the channel estimates. The UE then receives a first data transmission sent by the first cell to the UE based on the first channel estimate. The UE also receives a second data transmission sent by the second cell to another UE and steered away from the UE based on the second channel estimate. | 02-11-2010 |
20100035600 | COORDINATED TRANSMISSIONS BETWEEN CELLS OF A BASE STATION IN A WIRELESS COMMUNICATIONS SYSTEM - Systems and methods for providing coverage to a first cell through a first antenna system and coverage to a second cell through a second antenna system. Data is also processed for transmission to a mobile device in the first cell using the first and second antenna systems. | 02-11-2010 |
20100074152 | METHOD AND APPARATUS FOR TRANSMITTING DATA IN A TIME DIVISION DUPLEXED (TDD) COMMUNICATION SYSTEM - Techniques to process data for transmission in a time division duplexed (TDD) communication system. In one aspect, the frequency response of a forward link is estimated at a base station based on reverse link transmissions (e.g., pilots) from a terminal Prior to a data transmission on the forward link, the base station determines a reverse transfer function based on the pilots transmitted by the terminal, “calibrates” the reverse transfer function with a calibration function to derive an estimate of a forward transfer function, and preconditions modulation symbols based on weights derived from the forward transfer function. In another aspect, the terminal estimates the “quality” of the forward link and provides this information to the base station. The base station then uses the information to properly code and modulate data prior to transmission such that the transmitted data can be received by the terminal at the desired level of performance. | 03-25-2010 |
20100329369 | METHOD AND APPARATUS FOR FACILITATING MULTI-USER JOINT TRANSMIT-RECEIVE BEAMFORMING - A method of wireless communication is disclosed that includes receiving detected channel information from a plurality of access terminals; selecting a set of access terminals from the plurality of access terminals based on the received channel information; creating a beamforming vector for each access terminal in the set of selected access terminals; and transmitting a signal using at least one of the created beamforming vectors. An apparatus for performing the method is also disclosed herein. | 12-30-2010 |
Patent application number | Description | Published |
20090092087 | MULTI-ANTENNA TRANSMISSION FOR SPATIAL DIVISION MULTIPLE ACCESS - An uplink channel response matrix is obtained for each terminal and decomposed to obtain a steering vector used by the terminal to transmit on the uplink. An “effective” uplink channel response vector is formed for each terminal based on its steering vector and its channel response matrix. Multiple sets of terminals are evaluated based on their effective channel response vectors to determine the best set (e.g., with highest overall throughput) for uplink transmission. Each selected terminal performs spatial processing on its data symbol stream with its steering vector and transmits its spatially processed data symbol stream to an access point. The multiple selected terminals simultaneously transmit their data symbol streams via their respective MIMO channels to the access point. The access point performs receiver spatial processing on its received symbol streams in accordance with a receiver spatial processing technique to recover the data symbol streams transmitted by the selected terminals. | 04-09-2009 |
20090201839 | METHODS AND APPARATUS FOR REDUCING INTERFERENCE IN WIRELESS COMMUNICATION SYSTEMS - In accordance with a method for reducing interference in a wireless communication system, information about at least one disallowed beam corresponding to at least one served user may be determined. Scheduling decisions for served users may be made so as to avoid transmissions via the at least one disallowed beam. Data may be transmitted to users in accordance with the scheduling decisions. | 08-13-2009 |
20090201903 | SYSTEMS AND METHODS FOR DISTRIBUTED BEAMFORMING BASED ON CARRIER-TO-CAUSED INTERFERENCE - In accordance with a method for distributed beamforming based on carrier to caused interference, a base station may receive channel state information from users. The base station may select a codeword from a codebook. The codeword may be selected so as to maximize a utility function that is based on a signal-to-caused-interference-plus-noise ratio. The base station may use the codeword for beamforming. | 08-13-2009 |
20090252201 | PILOT INTERFERENCE CANCELLATION - Techniques for generalized pilot interference cancellation in a communications receiver. In an exemplary embodiment, a residual pilot is cancelled from a post-traffic cancellation signal following initial first-pass pilot cancellation. Residual pilot cancellation is achieved by adding the first-pass cancelled pilot as earlier stored in memory back to the post-traffic cancellation signal, and pilot filtering the resulting signal to generate an improved pilot interference estimate. In an alternative exemplary embodiment, an arbitrary number of iterations may be applied to generate the pilot interference estimate by successively storing each generated pilot interference estimate in memory. | 10-08-2009 |
20110069736 | METHOD AND APPARATUS FOR CANCELING PILOT INTERFERENCE IN A WIRELESS COMMUNICATION SYSTEM - Methods and systems for estimating and canceling pilot interference in a wireless (e.g., CDMA) communication system. In one method, a received signal comprised of a number of signal instances, each including a pilot, is initially processed to provide data samples. Each signal instance's pilot interference may be estimated by despreading the data samples with a spreading sequence for the signal instance, channelizing the despread data to provide pilot symbols, filtering the pilot symbols to estimate the channel response of the signal instance, and multiplying the estimated channel response with the spreading sequence. The pilot interference estimates due to a plurality of interfering multipaths are accumulated to derive the total pilot interference, which is subtracted from the data samples to provide pilot-canceled data samples. These samples are then processed to derive demodulated data for each of at least one (desired) signal instance in the received signal. | 03-24-2011 |
20120213302 | MULTI-ANTENNA TRANSMISSION FOR SPATIAL DIVISION MULTIPLE ACCESS - An uplink channel response matrix is obtained for each terminal and decomposed to obtain a steering vector used by the terminal to transmit on the uplink. An “effective” uplink channel response vector is formed for each terminal based on its steering vector and its channel response matrix. Multiple sets of terminals are evaluated based on their effective channel response vectors to determine the best set (e.g., with highest overall throughput) for uplink transmission. Each selected terminal performs spatial processing on its data symbol stream with its steering vector and transmits its spatially processed data symbol stream to an access point. The multiple selected terminals simultaneously transmit their data symbol streams via their respective MIMO channels to the access point. The access point performs receiver spatial processing on its received symbol streams in accordance with a receiver spatial processing technique to recover the data symbol streams transmitted by the selected terminals. | 08-23-2012 |
20120263164 | METHODS AND APPARATUS FOR ADJUSTING FORWARD LINK SIGNAL TO INTERFERENCE AND NOISE RATIO ESTIMATES - Methods and systems for adjusting a forward link (FL) signal to interference and noise ratio (SINR) are provided. In an example, a FL SINR is estimated for each user in a plurality of users, on at least one of each user's respective data rate control (DRC) message or each user's respective prior FL SINR value. The respective estimated FL SINR for a user in the plurality of users is increased, if, based on a reverse link acknowledge message, the user has decoded a packet before all symbols in the packet have been transmitted. Remaining control channel power is determined. The estimated FL SINR for all users in the plurality of users is increased if remaining control channel power is less than a low threshold. The estimated FL SINR for all users in the plurality of users is increased if the remaining control channel power is greater than a high threshold. | 10-18-2012 |
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 |