Techniques and examples of overhead reduction for linear combination codebook and feedback mechanism in mobile communications are described. A user equipment (UE) receives from a base station of a network one or more reference signals via a communication link between the UE and the base station. The UE constructs a channel state information (CSI) feedback by utilizing a correlation of channel responses in a frequency domain to reduce feedback overhead. The UE then transmits the CSI feedback to the base station.

A method for reporting a channel state of a downlink channel transmitted through two-dimensionally arranged N.sub.t number of antenna ports, according to one embodiment of the present disclosure, is performed by a terminal, and the method comprises the steps of: receiving a reference signal (RS) configuration for measuring a channel for the two-dimensionally arranged N.sub.t number of antenna ports, wherein the RS is code division multiplexed (CDM) and is transmitted through the N.sub.t number of antenna ports; and receiving the RS by using the received RS configuration, and calculating channel state information on a downlink channel so as to report the channel state information to a serving cell, wherein the reported channel state information includes a precoding matrix for the transmission of the RS, and the precoding matrix for the transmission of the RS can be subset of a codebook for a precoding matrix for the data transmission of the N.sub.t number of antenna ports.

Disclosed is a method by which a terminal transmits channel status information (CSI) feedback in a wireless communication system. Particularly, the method for transmitting CSI feedback comprises the steps of: setting, through an upper layer signal, one CSI process having a periodic reference signal and an aperiodic reference signal; receiving, from a base station, an aperiodic CSI feedback request message related to the one CSI process; generating, in response to the aperiodic CSI feedback request message, aperiodic CSI feedback on the basis of the aperiodic reference signal; and transmitting the aperiodic CSI feedback to the base station.

There is provided mechanisms for configuring an antenna system having individual antenna elements arranged in at least two antenna subarrays. Each pair of antenna subarrays has a respective first spatial separation. Each pair of the individual antenna elements has a respective second spatial separation. A method is performed by a network device. The method includes obtaining channel measurements for each of the at least two antenna subarrays. Channel covariance information between the subarrays using the obtained channel measurements is determined. Channel covariance information between all individual antenna elements of the antenna system is determined by interpolating the channel covariance information between the subarrays according to a spatial relation between all first spatial separations and all second spatial separations. Combining of the individual antenna elements of the antenna system is controlled based on the determined channel covariance information between all the individual antenna elements.

The present invention relates to a wireless communication system and, more specifically, to a method and an apparatus for reporting channel status information (CSI). Particularly, the method by which a terminal in the wireless communication system reports the CSI, comprises the steps of: receiving a reference signal from a base station; and reporting, to the base station, the CSI generated by using the reference signal, wherein the CSI includes channel information for a plurality of antenna ports mapped according to a first parameter, and the first parameter is a value related to vertical domain antenna ports indicated through upper layer signaling.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The UE receives RSs from a base station. The UE determines, based on the RSs, a second CSI indicator indicating a first precoding configuration of the base station optimized to at least one of improve signal power or reduce interference in an elevation dimension. The UE determines, based on the RSs, a second CSI indicator indicating a second precoding configuration of the base station optimized to at least one of improve the signal power or reduce interference in an azimuth dimension. The UE transmits, to the base station, a first CSI report including at least the first CSI indicator.

An electronic device for a first communication device equipped with a plurality of antennas of a wireless communication system includes a processing circuit configured to configure a first transmission from the first communication device to a second communication device based on a plurality of sets of first sub-configuration parameters separately, so that a specific set of first sub-configuration parameters are determined based on information related to the first transmission; configure a second transmission from the first communication device to a second communication device based on a plurality of sets of second sub-configuration parameters separately; and configure a subsequent transmission from the first communication device to a second communication device based on a specific set of first configuration parameters which are determined based on combination of the specific set of first sub-configuration parameters and the specific set of second sub-configuration parameters.

Embodiments of the present disclosure provide a method and apparatus for multi-input multi-output MIMO communications in a wireless communication network. The method comprises: receiving, from a device, long-term precoding information for the MIMO communication, the long-term precoding information indicating a first group of beams for a first antenna polarization, and a second group of beams for a second antenna polarization (S201); receiving, from the device, short-term precoding information for use in the MIMO communication, the short-term precoding information indicating beams selected respectively from the first group of beams and the second group of beams for different antenna polarizations (S202); constructing a precoding matrix for the MIMO communication according to the long-term precoding information and short-term precoding information (S203); and transmitting data encoded according to the precoding matrix to the device (S204). Embodiments of the present disclosure further provide a method in a receiving side of MIMO, and a corresponding apparatus.

For CSI reporting mechanisms, a user equipment (UE) includes a transceiver and a processor operably connected to the transceiver. The transceiver is configured to receive channel state information (CSI) process configuration information including at least one beamformed type associated with a plurality of non-zero-power (NZP) CSI reference signal (CSI-RS) resource configurations and receive a CSI-RS resource index (CRI) reporting configuration. The processor is configured to calculate, in response to receipt of the configuration information, a CRI and a channel quality indicator (CQI). The transceiver is further configured to report the CRI and the CQI by transmitting the CRI and the CQI on an uplink channel.

A method for feeding back information about a channel between antenna arrays is provided, which includes: receiving, by a first network device, channel information of NM sub-channels that is sent by a second network device, where an antenna array of the first network device includes M subarrays, an antenna array of the second network device includes N subarrays, a channel between the antenna array of the first network device and the antenna array of the second network device includes the NM sub-channels, M and N are positive integers and are not both 1, and the M subarrays and the N subarrays each include at least two antennas; and generating channel information of the channel between the antenna array of the first network device and the antenna array of the second network device according to the channel information of the NM sub-channels that is from the second network device.