Abstract: Apparatuses, methods, and systems for calibrating an antenna array are disclosed. One method includes selecting an antenna element of a first antenna subarray and an antenna element of a second antenna subarray, transmitting the signal through the at least one antenna element of the first subarray having a first selected phase, transmitting the signal through the at least one antenna element of the second subarray having a second selected phase, and characterizing a relative phase offset between the antenna element of the first antenna subarray and the antenna element of the second antenna subarray, including adjusting the first selected phase or the second selected phase, and monitoring a receive signal received at a calibration antenna that includes the transmitted signal of the at least one antenna element of the first antenna subarray and the transmitted signal of the at least one antenna element of second antenna subarray.

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: 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 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: 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.

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 receiver transmissions from a serving cell that serves the receiver and from one or more neighbor cells. The transmissions are received via multiple receive antennas to produce multiple respective output signals. The multiple output signals are weighed with respective weights, and the weighted output signals are combined to produce a combined output signal. The weights are selected so as to form a composite antenna pattern having a first antenna gain in one or more first directions that point toward the neighbor cells, and a second antenna gain, lower than the first antenna gain, in a second direction that points toward the serving cell. Characteristics of the one or more neighbor cells are measured by processing the combined output signal in which the transmissions received from the serving cell are attenuated.

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. A respective channel feedback for each of the multiple cells, and a single additional rich channel feedback having a higher information content than the channel feedback computed for the multiple cells, are calculated in the terminal based on the received signals. The channel feedback for the multiple cells is transmitted on a periodic uplink control channel, and the single rich channel feedback is transmitted on an a-periodic uplink channel.

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 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 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 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: Systems, methods, apparatus, and techniques are provided for retransmitting packets of data. A Radio Link Control (RLC) layer data packet is generated, and the RLC layer data packet is converted to one or more physical (PHY) layer data packets. The one or more PHY layer data packets are transmitted. At least one of a hybrid automatic transmission request (HARQ) acknowledgement (ACK) message and a HARQ negative acknowledgment (NACK) message is received from a receiver in response to transmission of the one or more PHY layer data packets. It is determined whether the at least one of the HARQ ACK message and the HARQ NACK message represents a automatic transmission request (ARQ) ACK message or a ARQ NACK message.

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: A method for mobile telecommunication 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 enable the first cell to precode a first signal destined for the terminal in response to the channel feedback with a first precoding vector, and to enable the second cell to precode a second signal destined for the terminal in response to the channel feedback with a second precoding vector that differs in magnitude from the first precoding vector. The first and second signals convey same data. The channel feedback is transmitted from the terminal. Calculating the channel feedback includes calculating one or more of a single-user Channel Quality Indicator (CQI), a multi-user CQI, and a non-cooperative-transmission CQI.

Abstract: A method includes, in a mobile communication terminal, receiving signals from a group of cells in multiple time-frequency Resource Elements (REs). The signals include a desired signal component and an interfering signal component. A subset of the REs, in which the cells are known deterministically to transmit at least part of the interfering signal component and to not transmit the desired signal component, is identified in the terminal. An interference caused by the interfering signal component to the desired signal component is estimated in the terminal, by measuring the signals in the REs in the subset.

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: 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: 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: A method in a mobile communication terminal includes receiving signals from a serving cell and from one or more interfering cells. Respective channel responses are estimated in the terminal for the signals received from the interfering cells. A level of interference, caused by the signals of the interfering cells to a signal received from the serving cell, is derived from the channel responses. A Signal to Noise Ratio (SNR) is calculated for the signal received from the serving cell based on the level of interference caused by the signals of the interfering cells. Feedback information is produced based on the SNR and transmitted from the terminal.