Abstract: An interference covariance calculation technique is selected at a first communication device, where the interference covariance calculation technique is to be utilized by a second communication device when computing a channel quality indicator (CQI) associated with a communication channel between the first communication device and the second communication device. The interference covariance calculation technique is selected from a set of multiple techniques for calculating interference covariance. The first communication device transmits an indication of the selected interference covariance calculation technique to the second communication device. The first communication device receives a CQI calculated by the second communication device in accordance with the selected interference covariance calculation technique.

Abstract: A method includes receiving in a mobile communication terminal over a communication channel a Multiple-Input Multiple-Output (MIMO) signal that includes at least a transmission addressed to the terminal. A Multi-User Signal to Noise Ratio (MU-SNR) is estimated in the terminal based on the received signal. The MU-SNR is indicative of a power ratio between the transmission addressed to the terminal and remaining components of the signal, which are assumed to include one or more transmissions addressed to one or more other terminals. Feedback, which is indicative of the communication channel and is based on the MU-SNR, is transmitted from the terminal.

Abstract: Some of the embodiments of the present disclosure provide a method comprising selecting, by a user equipment (UE), a preferred interference precoding matrix from a plurality of candidate precoding matrices included in a codebook; and transmitting, by the user equipment to a communication node, a preferred interference precoding matrix index (PMI) corresponding to the preferred interference precoding matrix included in the codebook. Other embodiments are also described and claimed.

Abstract: Some of the embodiments of the present disclosure provide a method within a wireless communication network, the method comprising, receiving by a user equipment (UE), a signal and interference component, wherein the interference component was transmitted in an unknown direction; and decoding, by the UE, the signal based at least in part on the interference component. Other embodiments are also described and claimed.

Abstract: A method includes receiving, in a communication terminal, signals from a group of cells. The group of cells cooperates in a Coordinated Multipoint (CoMP) transmission scheme that assigns multiple Channel State Information Reference Signals (CSI-RS) resources to the cells. A first subset of the CSI-RS resources is assigned to periodically report channel feedback on a first uplink channel, and a second subset of the CSI-RS resources is assigned to a-periodically report the channel feedback on a second uplink channel. The channel feedback is computed for the multiple CSI-RS resources. The channel feedback computed for the CSI-RS resources is transmitted in the first subset on the first uplink channel, and the channel feedback computed for the CSI-RS resources in the second subset is transmitted on the second uplink channel.

Abstract: A method includes receiving, at a communication terminal, signals from a group of cells that cooperate in a Coordinated Multipoint (CoMP) transmission scheme. Signaling that specifies a CoMP resource management (CRM) set is received at the communication terminal. The CRM set includes a subset of the cells in the group for which the communication terminal is to perform signal measurements. A size of the CRM set is restricted to a predefined maximum size. The signal measurements are performed at the communication terminal only on the signals received from one or more of the cells in the CRM set. The signal measurements performed on the one or more of the cells in the CRM set are reported from the communication terminal.

Abstract: Some of the embodiments of the present disclosure provide a method for reducing interference feedback in a mobile device operating in a wireless system employing coordinated transmission. The method comprises the mobile device establishing a plurality of channels with a plurality of base stations. The plurality of base stations includes a serving base station and one or more interfering base stations. The method further comprises the mobile device reporting, to the serving base station, reduced feedback information including a vector approximation of a feedback matrix associated with an interfering channel established with an interfering base station. Other embodiments are also described and claimed.

Abstract: Systems and methods for estimating characteristics of a channel are provided. A transmission of known reference data is received at a receiving device. The reference data is transmitted over the channel that includes one or more desired layers and one or more interfering layers. Characteristics of the channel are determined based on the known reference data, where the determining includes a joint estimation of the one or more desired layers and the one or more interfering layers. The determining includes selecting certain of the layers to be estimated at each of the known reference data and selecting certain of the layers to be estimated over a range of the known reference data. The determining includes solving an equation to jointly estimate the one or more desired layers and the one or more interfering layers based on the selections. The selections reduce a number of unknown values in the equation.

Abstract: 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.

Abstract: A method for signal processing in a receiver includes receiving in the receiver a Multi-User Multiple-Input Multiple-Output (MU-MIMO) signal. The MU-MIMO signal includes at least a first signal, which is precoded using a first precoding scheme and is addressed to the receiver, and a second signal, which is precoded using a second precoding scheme. An average error rate achievable in decoding the first signal in the presence of the second signal is computed. The average error rate is computed over a set of possible choices of the second precoding scheme. The first precoding scheme is selected from among a plurality of available precoding schemes so as to satisfy a criterion defined over the average error rate. The receiver sends feedback to a transmitter transmitting the first signal. The feedback depends on the selected first precoding scheme and causes the transmitter to control transmission of the first signal.

Abstract: A method for communication includes, in a transmitter having a first number of transmit antenna ports, setting an upper limit on a second number of spatial layers to be used by the transmitter to be less than the first number. An actual number of the spatial layers, which does not exceed the upper limit, is allocated for transmission to a given receiver. One or more streams of modulated symbols are mapped onto the allocated actual number of the spatial layers. The actual number of the spatial layers are transmitted from the transmitter to the given receiver. A precoding operation maps the spatial layers onto the transmit antenna ports. A first upper limit is set when the precoding operation depends on feedback from the given receiver. A second upper limit, which does not exceed the first upper limit, is set when the precoding operation is not dependent on the feedback.

Abstract: A method includes, in a mobile communication terminal, receiving from at least first and second base stations, which cooperate in a coordinated transmission scheme, signals that are transmitted over respective first and second communication channels. Respective channel measures are calculated for the communication channels based on the received signals. First and second feedback data, which are indicative of the respective channel measures of the first and second communication channels, are formulated such that the first feedback data has a first data size and the second feedback data has a second data size, different from the first data size. The first and second feedback data are transmitted from the mobile communication terminal to at least one of the base stations.

Abstract: 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.

Abstract: 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.

Abstract: A method includes receiving in a mobile communication terminal over a communication channel a Multiple-Input Multiple-Output (MIMO) signal that includes at least a transmission addressed to the terminal. A Multi-User Signal to Noise Ratio (MU-SNR) is estimated in the terminal based on the received signal. The MU-SNR is indicative of a power ratio between the transmission addressed to the terminal and remaining components of the signal, which are assumed to include one or more transmissions addressed to one or more other terminals. Feedback, which is indicative of the communication channel and is based on the MU-SNR, is transmitted from the terminal.

Abstract: A method includes receiving a Multiple-Input Multiple Output (MIMO) signal over multiple communication channels from an antenna array including a first set of antennas having a first polarization and a second set of the antennas having a second polarization that is orthogonal to the first polarization. First feedback information is calculated relating to first interrelations between the antennas within either the first set or the second set. Second feedback information is calculated relating at least to second interrelations between the first set and the second set of the antennas. The first feedback information is transmitted at a first time/frequency granularity, and the second feedback information is transmitted at a second time/frequency granularity that is finer than the first time/frequency granularity.

Abstract: A method includes, in a mobile communication terminal, receiving from at least first and second base stations, which cooperate in a coordinated transmission scheme, signals that are transmitted over respective first and second communication channels. Respective channel measures are calculated for the communication channels based on the received signals. First and second feedback data, which are indicative of the respective channel measures of the first and second communication channels, are formulated such that the first feedback data has a first data size and the second feedback data has a second data size, different from the first data size. The first and second feedback data are transmitted from the mobile communication terminal to at least one of the base stations.

Abstract: A method for signal processing in a receiver includes receiving in the receiver a Multi-User Multiple-Input Multiple-Output (MU-MIMO) signal. The MU-MIMO signal includes at least a first signal, which is precoded using a first precoding scheme and is addressed to the receiver, and a second signal, which is precoded using a second precoding scheme. An average error rate achievable in decoding the first signal in the presence of the second signal is computed. The average error rate is computed over a set of possible choices of the second precoding scheme. The first precoding scheme is selected from among a plurality of available precoding schemes so as to satisfy a criterion defined over the average error rate. The receiver sends feedback to a transmitter transmitting the first signal. The feedback depends on the selected first precoding scheme and causes the transmitter to control transmission of the first signal.

Abstract: Some of the embodiments of the present disclosure provide a method within a wireless communication network, the method comprising, receiving by a user equipment (UE), a signal and interference component, wherein the interference component was transmitted in an unknown direction; and decoding, by the UE, the signal based at least in part on the interference component. Other embodiments are also described and claimed.

Abstract: A method for communication includes, in a transmitter having a first number of transmit antenna ports, setting an upper limit on a second number of spatial layers to be used by the transmitter to be less than the first number. An actual number of the spatial layers, which does not exceed the upper limit, is allocated for transmission to a given receiver. One or more streams of modulated symbols are mapped onto the allocated actual number of the spatial layers. The actual number of the spatial layers are transmitted from the transmitter to the given receiver.