| Patent application number | Description | Published |
|---|
| 20080303699 | MIMO wireless precoding system robust to power imbalance - The present invention relates to methods and apparatus for preventing power imbalance in a multiple input multiple output (MIMO) wireless precoding system. According to one aspect of the present invention, a codebook is constructed with a first subset of codewords that are constant modulus matrices, and a second subset of codewords that are non-constant modulus matrices. A mapping scheme is established between the first subset of codewords and the second subset of codewords. When a unit of user equipment feeds back a first codeword that is a non-constant modulus matrix, the Node-B may replace the first codewords with a second codeword that is selected from the first subset of codewords and that corresponds to the first codeword in accordance with the mapping scheme. | 12-11-2008 |
| 20100173660 | COORDINATED MULTIPOINT (CoMP) JOINT TRANSMISSION USING CHANNEL INFORMATION FEEDBACK AND HIGHER RANK DEDICATED BEAM-FORMING - A subscriber station is provided. The subscriber station comprises a receiver configured to listen for downlink control information for coordinated multipoint (CoMP) joint transmission only from an anchor cell, and to receive the downlink control information for CoMP joint transmission from the anchor cell. | 07-08-2010 |
| 20100272206 | TRANSMITTING/RECEIVING APPARATUS AND METHOD THEREOF IN CODEBOOK BASED MULTIPLE ANTENNA SYSTEM - A transmission/reception apparatus and a method thereof in a codebook-based multiple antenna system is provided. In a transmission method in a codebook-based Multiple Input Multiple Output (MIMO) system, control information is received from a receiver. A codeword is determined within an Open-Loop (OL)-MIMO codebook where a Closed-Loop (CL)-MIMO codebook is reused based on the control information. At least one data stream is transmitted via at least one antenna using the determined codeword. | 10-28-2010 |
| 20110002404 | ROTATING REFERENCE CODEBOOK THAT IS USED IN A MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM - A rotating reference codebook used in a multiple input multiple output (MIMO) communication system is provided. The reference codebook includes codewords from a discrete Fourier transform (DFT) codebook. A base station and a terminal may calculate a rotation matrix based on a previous preferred codeword and a random codeword among codewords included in the DFT codebook. A reference codebook may be rotated using the rotation matrix and may be transformed to a new codebook. The reference codebook may include codewords of a polar cap codebook and the codewords of the DFT codebook. Even though the codewords of the DFT codebook are rotated, the codewords of the DFT codebook may remain in the new codebook as elements of the DFT codebook. | 01-06-2011 |
| 20110064051 | CLUSTERED MULTI-CELL MULTI-USER MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM USING CELL-EDGE USER SELECTION SCHEME - Provided is a control method of a control apparatus for a multi-cell communication system including a plurality of cells, the method including determining a cell edge terminal or an inner cell terminal from each of terminals included in each of the cells, and selecting, from base stations included in the plurality of cells, a first base station and a second base station. The first base station may serve all of a corresponding cell edge terminal and a corresponding inner cell terminal, and the second base station may serve only the corresponding inner cell terminal between the corresponding cell edge terminal and the corresponding inner cell terminal. | 03-17-2011 |
| 20110080971 | MULTIPLE-INPUT MULTIPLE-OUTPUT COMMUNICATION SYSTEM USING EXPLICIT FEEDBACK - A multiple input multiple output (MIMO) communication system using an explicit feedback is provided. In the MIMO communication system using the explicit feedback, a receiver may generate an explicit feedback vector by calculating an explicit channel matrix, and by vectorizing the explicit channel matrix or an explicit channel matrix processed using a predefined function. Feedback information generated based on the explicit feedback vector may be provided to a transmitter. The transmitter may reconfigure the explicit channel matrix or the processed explicit channel matrix based on the feedback information. The transmitter and the receiver may share the explicit channel matrix or the processed explicit channel matrix using an adaptively transformed codebook. | 04-07-2011 |
| 20110096755 | CODEBOOK FOR MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION AND COMMUNICATION DEVICE USING THE CODEBOOK - In a multi-user multiple input multiple output (MIMO) communication, each of receivers may use a different channel codebook and a transmitter may determine beamforming vectors using a beamforming codebook corresponding to each of the receivers. | 04-28-2011 |
| 20110164696 | MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM USING A CODEBOOK AND METHOD OF DESIGNING THE CODEBOOK - Provided is a multiple input multiple output (MIMO) communication system using a codebook. A transmitter and a receiver included in the MIMO communication system may generate a codebook having a different size for each eigenvector of a channel matrix or a channel covariance matrix, based on eigenvalues of the channel matrix or the channel covariance matrix. | 07-07-2011 |
