Patent application number | Description | Published |
20090154627 | METHODS AND APPARATUS FOR IDENTIFYING A PREAMBLE SEQUENCE AND FOR ESTIMATING AN INTEGER CARRIER FREQUENCY OFFSET - In accordance with a method for identifying a preamble sequence and for estimating an integer carrier frequency offset, a signal that comprises a preamble sequence from a set of possible preamble sequences is received. A reduced set of integer carrier frequency offset (CFO) candidates may be determined. Cross-correlation operations may be performed with respect to the received signal and multiple candidate transmitted signals. Each candidate transmitted signal may include one of the set of possible preamble sequences. In addition, each candidate transmitted signal may correspond to one of the reduced set of integer CFO candidates. Multiple correlation values may be determined as a result of the cross-correlation operations. The correlation values may be used to identify the preamble sequence and to estimate the integer CFO. | 06-18-2009 |
20090175387 | DECODING SCHEME USING MULTIPLE HYPOTHESES ABOUT TRANSMITTED MESSAGES - A method and apparatus for decoding encoded data bits of a wireless communication transmission are provided. A set of a-priori bit values corresponding to known bit values of the encoded data bits may be generated. Decoding paths that correspond to decoded data bits that are inconsistent with the a-priori bit values may be removed from the possible decoding paths to consider, and decoding the encoded data bits by selecting a decoding path from remaining decoding paths of the possible decoding paths that were not removed. Multiple hypotheses, each corresponding to a different set of a-prior bit values may be evaluated, with the decoded data for a hypothesis selected based on the evaluation output for further processing. | 07-09-2009 |
20090175388 | DECODING SCHEME USING A-PRIORI INFORMATION ABOUT TRANSMITTED MESSAGES - A method and apparatus for decoding encoded data bits of a wireless communication transmission are provided. A set of a-priori bit values corresponding to known bit values of the encoded data bits may be generated. Decoding paths that correspond to decoded data bits that are inconsistent with the a-priori bit values may be removed from the possible decoding paths to consider, and decoding the encoded data bits by selecting a decoding path from remaining decoding paths of the possible decoding paths that were not removed. | 07-09-2009 |
20090175394 | METHODS AND APPARATUS FOR SYNCHRONIZATION AND DETECTION IN WIRELESS COMMUNICATION SYSTEMS - A synchronization and detection method in a wireless device may include performing coarse detection and synchronization with respect to a received signal. The synchronization and detection method may also include performing fine detection and synchronization for acquisition of the received signal. Results of the coarse detection and synchronization may be used for the fine detection and synchronization. The synchronization and detection method may also include performing tracking mode processing when the acquisition of the received signal has been achieved. | 07-09-2009 |
20090285316 | METHODS AND SYSTEMS FOR INITIAL FCH PROCESSING - Methods and apparatus for initially decoding a frame control header (FCH) in an orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) system in an effort to accurately determine the downlink frame prefix (DLFP) such that the remainder of an OFDM/A frame may be properly decoded are provided. Used, for example, when boosting factors applied in the transmitter to various elements of the OFDM/A frame and/or available pilots for the FCH are unknown, such methods may utilize a preamble channel estimate, the FCH pilots, or a combination thereof. | 11-19-2009 |
20090285317 | METHODS AND SYSTEMS FOR EFFECTIVE CHANNEL ESTIMATION IN OFDM SYSTEMS - A method and apparatus for channel estimation in wireless communications are provided. After an initial channel estimation and an estimation of the effective channel length (ECL) are performed, a weighting based on the ECL may be applied in an effort to remove noise from the initial channel estimate and provide an estimated channel with increased accuracy. Different weightings may apply for different channel lengths. A threshold may be used during the ECL estimation, and the threshold may be predetermined or calculated in an effort to adapt to different channel environments. | 11-19-2009 |
20090290618 | METHODS AND SYSTEMS FOR HYBRID MIMO SCHEMES IN OFDM/A SYSTEMS - Certain embodiments of the present disclosure provide a hybrid receiver diversity scheme that involves combining received signals in accordance with a combination of multiple receive diversity schemes. Certain embodiments of the present disclosure provide a hybrid transmit diversity scheme that involves transmitting diversity signals to a receiver according to a transmit diversity scheme selected based on signal quality measurements received from the receiver. | 11-26-2009 |
20100095189 | METHODS AND SYSTEMS FOR MODIFIED MAXIMUM-LIKELIHOOD BASED TBCC DECODING - A method and apparatus for decoding of tailbiting convolutional codes (TBCC) are disclosed. The proposed modified maximum-likelihood TBCC decoding technique preserves error correction performance of optimal maximum-likelihood based TBCC decoding, while the computational complexity is substantially decreased since a reduced number of decoding states has been evaluated. Compare to other sub-optimal TBCC decoding algorithms, modified maximum-likelihood TBCC decoding achieves improved packet error rate performance with similar computational complexity. | 04-15-2010 |
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 |