Abstract: The present disclosure includes systems and techniques relating to processing received spatially diverse transmissions. In some implementations, an apparatus includes: circuitry configured to receive signals from separate communication inputs; circuitry configured to filter the signals to reduce noise, interference, or both; circuitry configured to estimate covariance of the separate communication inputs, including estimating a correlation between the separate communication inputs; and circuitry configured to apply the covariance estimation to the filtering circuitry to effect noise whitening and to force an underestimation of the correlation between the separate communication inputs as applied.

Abstract: 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.

Abstract: In accordance with an embodiment, there is provided a method comprising receiving, at a receiver, a desired signal and an interfering signal, wherein the interfering signal was transmitted with a modulation unknown to the receiver; identifying a likely modulation corresponding to the modulation with which the interfering signal was transmitted; and decoding the desired signal using a modulation dependent multiple-input multiple output (MIMO) detection, wherein the modulation dependent MIMO detection is based at least in part on the identified likely modulation corresponding to the modulation with which the interfering signal was transmitted, wherein the modulation dependent MIMO detection includes maximum likelihood (ML) detection.

Abstract: A method includes receiving in a mobile communication terminal from a base station a precoded Multiple-Input Multiple-Output (MIMO) signal, which includes a first signal component transmitted by one or more first antennas of the base station at a first polarization, and further comprises a second signal component transmitted by one or more second antennas of the base station at a second polarization, different from the first polarization. A difference between respective signal magnitudes of the first signal component having the first polarization and the second signal component having the second polarization that have been received in the terminal is estimated in the terminal. Feedback information, which requests the base station to precode subsequent MIMO signals with a precoding matrix that is specified as a function of the difference between the signal magnitudes, is calculated and transmitted from the terminal.

Abstract: Systems and methods for establishing transmission format parameters between communication devices are provided. In some aspects, a method includes identifying, by a first base station, a first communication session with a first user equipment. A master set of transmission format parameters is shared between the first base station and the first user equipment. The method also includes assigning a first subset of the master set of transmission format parameters to the first communication session. The first subset is specifically assigned to the first communication session and specifies which of the master set of transmission format parameters is allocated for use in the first communication session. The method also includes transmitting an indicator of the first subset to the first user equipment.

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 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.

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 signals from a group of cells that cooperate in a Coordinated Multipoint (CoMP) transmission scheme. Signaling information is received from a first cell in the group. The signaling information is indicative of a first pattern of time-frequency Resource Elements (REs) used by the first cell for transmitting reference signals, and is further indicative of a second pattern of the REs used by a second cell in the group for transmitting the reference signals. A third pattern of the REs, which are available for receiving data from the cells, is derived in the terminal from the signaling information that is indicative of the first and second patterns. The data from the cells is received in the terminal in one or more of the REs in the third pattern.

Abstract: A method includes receiving in a communication terminal a sequence of downlink frames from a communication network that includes multiple cells arranged in first and second layers. The first layer corresponds to a first class of cells selected from a group of classes consisting of macro-cells, micro-cells, pico-cells, femto-cells and low-power nodes (LPN). The second layer corresponds to a second class of cells, different from the first class. One or more cross-layer frames in which at least a first cell in the first layer and at least a second cell in the second layer transmit data, and one or more same-layer frames in which only one or more of the cells in a single layer that currently serves the terminal transmit the data, are identified in the sequence. Cross-layer channel feedback is calculated over the cross-layer frames, and same-layer channel feedback is calculated over the same-layer frames.

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: 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: In accordance with an embodiment, there is provided a method comprising receiving, at a receiver, a desired signal and an interfering signal, wherein the interfering signal was transmitted with a modulation unknown to the receiver; identifying a likely modulation corresponding to the modulation with which the interfering signal was transmitted; and decoding the desired signal using a modulation dependent multiple-input multiple output (MIMO) detection, wherein the modulation dependent MIMO detection is based at least in part on the identified likely modulation corresponding to the modulation with which the interfering signal was transmitted, wherein the modulation dependent MIMO detection includes maximum likelihood (ML) detection.

Abstract: Systems using a transmit precoder codebook designed for a four-transmitter (4Tx) antenna configuration are described. The 4Tx antenna configuration is an attractive option for base stations in cellular network environments due to site-acquiring advantages and robust performance. In an embodiment, the transmit precoder codebook can be used for a variety of transmit antenna configurations and has a high resolution to enable beamforming and/or nulling. In another embodiment, the transmit precoder codebook is a two-component codebook, with a first precoder component signaled at a first frequency and a second precoder component signaled at a second higher frequency.

Abstract: Systems and methods for efficient link adaptation in multi-access wireless communication networks, including link adaptation in scenarios with non-collocated and/or power imbalanced base station transmit antennas are provided. In an embodiment, an indication of signal powers of the transmit antennas is signaled by the network to the user equipment (UE) when the UE is configured for logical antenna. ports using non-collocated and/or power imbalanced transmit antennas. The UE can use the indication of signal powers in determining the Precoding Matrix Indicator (PMI) and the Channel Quality Indicator (CQI), resulting in higher accuracy link adaptation.

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 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: Embodiments provide systems and methods for interference management in wireless multi-access communication networks, and more particularly systems and methods to enable reduction and/or suppression of interference. Embodiments for interference reduction include, without limitation, systems and methods to enable interference alignment, interference avoidance, and/or joint transmission to a user equipment (UE). Embodiments for enabling suppression of interference include, without limitation, systems and methods for feedback (from a UE to a network) or feedforward (from the network to the UE) signaling to enable interference estimation at the network/UE.

Abstract: Systems and methods for establishing transmission format parameters between communication devices are provided. In some aspects, a method includes identifying, by a first base station, a first communication session with a first user equipment. A master set of transmission format parameters is shared between the first base station and the first user equipment. The method also includes assigning a first subset of the master set of transmission format parameters to the first communication session. The first subset is specifically assigned to the first communication session and specifies which of the master set of transmission format parameters is allocated for use in the first communication session. The method also includes transmitting an indicator of the first subset to the first user equipment.

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.