Patent application number | Description | Published |
20120250550 | CHANNEL FEEDBACK FOR COOPERATIVE MULTIPOINT TRANSMISSION - A method includes receiving in a mobile communication terminal downlink signals from at least first and second cells that coordinate transmission of the downlink signals with one another. Channel feedback is calculated in the terminal based on the received downlink signals. The channel feedback is configured to cause the first cell to precode subsequent downlink signals in response to the channel feedback with a first precoding vector, and to cause the second cell to precode the subsequent downlink signals in response to the channel feedback with a second precoding vector that differs in magnitude from the first precoding vector. The channel feedback is transmitted from the terminal. | 10-04-2012 |
20130114654 | PRECODING FEEDBACK FOR CROSS-POLARIZED ANTENNAS WITH MAGNITUDE INFORMATION - A method includes receiving in a mobile communication terminal a precoded Multiple-Input Multiple-Output (MIMO) signal, which includes first and second signal components transmitted at respective different first and second polarizations. A difference between respective signal magnitudes of the first and second signal components received in the terminal is estimated in the terminal. Feedback information, which includes at least an indication of the difference between the signal magnitudes, is calculated and transmitted from the terminal. | 05-09-2013 |
20130114655 | CODEBOOK SUB-SAMPLING FOR FREQUENCY-SELECTIVE PRECODING FEEDBACK - A method includes, in a mobile communication terminal, holding a definition of a sub-sampled codebook identifying precoding matrices, which are selected from a master codebook that is made-up of a wideband codebook and a frequency-selective codebook. The definition defines a first subset of the wideband codebook and a second subset of the frequency-selective codebook. The second subset of the frequency-selective codebook is represented using no more than two bits. A Multiple-Input Multiple-Output (MIMO) signal is received in the terminal. Based on the received MIMO signal, one or more precoding matrices are selected from the sub-sampled codebook for precoding subsequent MIMO signals transmitted to the terminal, and precoding feedback indicating the selected precoding matrices is calculated. The precoding feedback is transmitted from the terminal. | 05-09-2013 |
20130122953 | DIFFERENTIAL CQI ENCODING FOR COOPERATIVE MULTIPOINT FEEDBACK - A method includes receiving in a mobile communication terminal signals from multiple cells that coordinate transmission of the signals with one another in a Cooperative Multipoint (CoMP) scheme. At least first and second Channel Quality Indicators (CQIs), for respective communication channels over which the signals are received, are calculated in the terminal based on the received signals. The second CQI is differentially encoded relative to the first CQI. Feedback information, including the first CQI and the differentially-encoded second CQI, is transmitted from the terminal. | 05-16-2013 |
20130155921 | ENHANCED DEMODULATION REFERENCE SIGNAL (DM-RS) DESIGN - A method in a mobile communication terminal includes receiving a Multi-User Multiple-Input Multiple-Output (MU-MIMO) signal, which includes at least a precoded transmission that is addressed to the terminal and which includes one or more Demodulation Reference Signals (DM-RS). Control information, which indicates one or more scrambling sequences and one or more orthogonalization sequences used in producing the DM-RS, is received in the mobile communication terminal. The control information is provided in a format that does not permit signaling of every possible scrambling sequence and orthogonalization sequence selection. The control information is interpreted in the mobile communication terminal so as to identify the scrambling sequences and orthogonalization sequences used in producing the DM-RS, and the DM-RS are demodulated using the identified scrambling sequences and orthogonalization sequences. | 06-20-2013 |
20130156001 | REFERENCE SIGNAL DESIGN FOR COORDINATED MULTIPOINT TRANSMISSION - A method includes controlling a set of transmission points, which are configured to operate in accordance with a Coordinated Multipoint (CoMP) transmission scheme, to simultaneously transmit a composite Reference Signal (RS) to a mobile communication terminal. Feedback, which is indicative of a response of a composite communication channel between the transmission points and the terminal, is received from the terminal. The feedback is estimated in the terminal based on the composite RS received in the terminal from the transmission points. Subsequent transmission from the transmission points is configured based on the received feedback. | 06-20-2013 |
20140286452 | CODEBOOK SUBSAMPLING FOR PUCCH FEEDBACK - A method in a mobile communication terminal includes holding a definition of a sub-sampled codebook identifying precoding matrices to be used for providing precoding feedback by the terminal The precoding matrices in the sub-sampled codebook are selected from a master codebook that is made-up of a long-term sub-codebook and a short-term sub-codebook. The definition defines a first subset of the long-term sub-codebook and a second subset of the short-term sub-codebook. A Multiple-Input Multiple-Output (MIMO) signal is received in the terminal via multiple receive antennas. Based on the received MIMO signal, a precoding matrix is selected from the sub-sampled codebook for precoding subsequent MIMO signals transmitted to the terminal. The precoding feedback indicating the selected precoding matrix is calculated. | 09-25-2014 |
20150236838 | METHOD AND APPARATUS FOR PROVIDING CHANNEL INFORMATION TO A MOBILE COMMUNICATION TERMINAL IN A MIMO COMMUNICATION SYSTEM - A method includes receiving in a mobile communication terminal signals from multiple cells that coordinate transmission of the signals with one another in a Cooperative Multipoint (CoMP) scheme. At least first and second Channel Quality Indicators (CQIs), for respective communication channels over which the signals are received, are calculated in the terminal based on the received signals. The second CQI is differentially encoded relative to the first CQI. Feedback information, including the first CQI and the differentially-encoded second CQI, is transmitted from the terminal. | 08-20-2015 |