Patent application number | Description | Published |
20090080495 | GROUPWISE SUCCESSIVE INTERFERENCE CANCELLATION FOR BLOCK TRANSMISSION WITH RECEPTION DIVERSITY - A plurality of data signals are received over an antenna array having a plurality of antenna elements. The data signals are transmitted over a shared spectrum in a wireless communication system. A signal having each of the data signals is received over each antenna element. The plurality of data signals are grouped into a plurality of groups. The received signals of the antenna elements are matched filtered for a first group of the plurality of groups, producing a matched filtered result. Data is jointly detected of the first group using the matched filtered result. An interference correction signal is constructed using the detected data for each antenna element. The interference cancelled result is subtracted from the received signal of each antenna element, producing an interference cancelled result for each antenna element. Data is successively detected for remaining groups using the interference cancelled result for each antenna element. | 03-26-2009 |
20090129447 | EFFICIENT JOINT DETECTION - K data signals, or bursts, are transmitted over a shared spectrum in a code division multiple access communication format. A combined signal is received and sampled over the shared spectrum, as a plurality of received vector versions. The combined signal includes the K transmitted data signals. A plurality of system matrices and an associated covariance matrix using codes and estimated impulse responses of the K data signals is produced. Each system matrix corresponds to a received vector version. The system and covariance matrices are extended and approximated as block circulant matrices. A diagonal matrix of each of the extended and approximated system and covariance matrices are determined by prime factor algorithm-fast Fourier transform (PFA-FFT) without division of the matrix. The received vector versions are extended. A product of the diagonal matrices and the extended received vector versions is taken. An inverse block discrete Fourier transform is performed by a PFA-FFT on a result of the product to produce the estimated data of the K data signals. | 05-21-2009 |
20090129499 | METHOD AND APPARATUS FOR IMPLEMENTING SPACE FREQUENCY BLOCK CODING IN AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING WIRELESS COMMUNICATION SYSTEM - The present invention is related to a method and apparatus for implementing space frequency block coding (SFBC) in an orthogonal frequency division multiplexing (OFDM) wireless communication system. The present invention is applicable to both a closed loop mode and an open loop mode. In the closed loop mode, power loading and eigen-beamforming are performed based on channel state information (CSI). A channel coded data stream is multiplexed into two or more data streams. Power loading is performed based on the CSI on each of the multiplexed data streams. SFBC encoding is performed on the data streams for each of the paired subcarriers. Then, eigen-beamforming is performed based on the CSI to distribute eigenbeams to multiple transmit antennas. The power loading may be performed on two or more SFBC encoding blocks or on each eigenmodes. Additionally, the power loading may be performed across subcarriers or subcarrier groups for weak eigenmodes. | 05-21-2009 |
20090201905 | METHOD AND APPARATUS FOR ESTIMATING CHANNELIZATION CODES IN A WIRELESS TRANSMIT/RECEIVE UNIT - A method and apparatus for estimating channelization codes in a wireless transmit/receive unit (WTRU) using blind code detection (BCD). A WTRU receives communication bursts and detects a midamble in the received burst. A candidate code list is generated in accordance with the detected midamble. The candidate code list includes channelization codes intended for both the intended WTRU and other WTRUs. Active channelization codes among the codes in the candidate list are identified, and the identified codes are forwarded to a multi-user detector (MUD). Since the orthogonal variable spreading factor code maintains the orthogonality between codes of different SF, SFs of other WTRUs follow the SF of the intended WTRU. Moreover, since the data for other WTRUs is not used in symbol processing after MUD, the performance of MUD for the intended WTRU is preserved with the SF ambiguity of other WTRUs. | 08-13-2009 |
20090316307 | METHOD AND APPARATUS TO IMPROVE CHANNEL QUALITY FOR USE IN WIRELESS COMMUNICATIONS SYSTEMS WITH MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) ANTENNAS - Apparatus and method that employ a technique which improves SINR in a communication system utilizing MIMO antennas are described. Transmitter and receiver components use fixed transmit and receive beamforming matrices and variable transmit and receive beamforming vectors. A method of channel conditioning using an iterative closed loop process is also described. | 12-24-2009 |
20100103985 | METHOD AND APPARATUS FOR REDUCING MULTI-USER PROCESSING IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus is disclosed for reducing multi-user processing at the receiver in wireless communication systems. Detected codes are grouped according to channel impulse response and a parent code is identified for each group of detected codes. A matrix A is constructed and joint detection is performed using the identified parent codes. Data symbols of the detected codes are obtained from the data symbols of the identified parent codes. | 04-29-2010 |
20120027053 | METHOD AND APPARATUS FOR REDUCING MULTI-USER PROCESSING IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus is disclosed for reducing multi-user processing at the receiver in wireless communication systems. Detected codes are grouped according to channel impulse response and a parent code is identified for each group of detected codes. A matrix A is constructed and joint detection is performed using the identified parent codes. Data symbols of the detected codes are obtained from the data symbols of the identified parent codes. | 02-02-2012 |
20120140845 | METHOD AND APPARATUS FOR COMBINING SPACE-FREQUENCY BLOCK CODING SPATIAL MULTIPLEXING AND BEAMFORMING IN A MIMO-OFDM SYSTEM - A method and apparatus for combining space-frequency block coding (SFBC) and frequency shift transmit diversity (FSTD) in a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system. | 06-07-2012 |
20120314740 | GROUPWISE SUCCESSIVE INTERFERENCE CANCELLATION FOR BLOCK TRANSMISSION WITH RECEPTION DIVERSITY - A plurality of data signals are received over an antenna array having a plurality of antenna elements. The data signals are transmitted over a shared spectrum in a wireless communication system. A signal having each of the data signals is received over each antenna element. The plurality of data signals are grouped into a plurality of groups. The received signals of the antenna elements are matched filtered for a first group of the plurality of groups, producing a matched filtered result. Data is jointly detected of the first group using the matched filtered result. An interference correction signal is constructed using the detected data for each antenna element. The interference cancelled result is subtracted from the received signal of each antenna element, producing an interference cancelled result for each antenna element. Data is successively detected for remaining groups using the interference cancelled result for each antenna element. | 12-13-2012 |