In an aspect of the present invention, a method for reporting channel state information (CSI) of a UE in a wireless communication system includes: receiving, from an eNB, CSI-RS resource information related to a CSI-RS resource to which a channel state information-reference signal (CSI-RS) is mapped; receiving the CSI-RS transmitted through one or more antenna ports from the eNB based on the received CSI-RS resource information; and reporting CSI generated based on the received CSI-RS to the eNB, in which the CSI-RS resource is configured by aggregating a plurality of CSI-RS resources, and the aggregated CSI-RS resources are respectively positioned in different subframes on a time axis or in different resource blocks on a frequency axis.

A base station and mobile device (UE) may coordinate transmission of reference signals and reception of corresponding channel state information (CSI) reports. If a periodic reference signal is scheduled for transmission outside the on-duration period of the UE, even if the reference signal corresponds to a periodic CSI report scheduled to be transmitted by the UE during the on-duration period, the base station may not transmit the periodic reference signal, thereby allowing the UE not to prematurely exit a low-power state. The base station may instead transmit an aperiodic reference signal at a specified point in time later than the scheduled transmission of the periodic reference signal. The UE may receive the aperiodic reference signal and either transmit the periodic CSI report or an aperiodic CSI report in response, depending on how close to the start of the on-duration period the transmission of the periodic CSI report is scheduled.

Apparatuses and methods are disclosed for supporting a UE in reporting of a selection of an NZP CSI-RS resource to an eNB supporting FD-MIMO communication. Each NZP CSI-RS resource is associated with a unique NZP CRI (or Beam Index) on a given serving cell. The UE may select an NZP CSI-RS resource for CSI calculation and reporting to the eNB based on processed CSI-RS signals received at an antenna of the UE from the eNB of a serving cell of the UE based on a CSI-RS resource configuration for the UE signaled from the eNB. The UE may report a CRI and a CSI of the selected NZP CSI-RS resource to the eNB of the serving cell of the UE based on a CRI reporting configuration of the UE signaled from the eNB.

Embodiments of the present invention provide a method and device for reducing complexity of channel quantization. The method comprises: determining, on the basis of whether a measurement feedback parameter configured by a channel state information (CSI) process satisfies a predetermined condition, a CSI report time-domain position and a time interval requirement parameter Nrpt-ref for a CSI reference resource time-domain position, or determining a CSI trigger time-domain position and a time interval requirement parameter Nrpt-ref for a CSI reference resource time-domain position; determining, according to the determined time interval requirement parameter Nrpt-ref and the CSI report time-domain position, the CSI reference resource time-domain position, or determining, according to the determined time interval requirement parameter Nrpt-ref and the CSI trigger time-domain position, the CSI reference resource time-domain position; and performing CSI quantization according to the determined CSI reference resource time-domain position.

Various embodiments include an apparatus to be employed by an enhanced Node B (eNB), the apparatus comprising communication circuitry to receive, from a user equipment (UE), feedback information and control circuitry, coupled with the communication circuitry, to identify a codeword from a three-dimensional codebook based on the feedback information received from the UE, wherein the communication circuitry is further to precode data to be transmitted to the UE based on the codeword. An apparatus to be employed by a UE and additional methods are described.

A method performed by a User Equipment(UE) is performed. The UE obtains (202) a beam reporting configuration. The beam reporting configuration defines a beam reporting procedure for determining an optimal beam for each of different sub-bands of a system bandwidth. The UE measures (204) different reference signals transmitted by the network node. The measured different reference signals correspond to each of the different sub-bands according to the beam reporting configuration. The UE then determines (206) a preferred beam for each of the different sub-bands based on the corresponding received reference signals.

An electronic device at a base station end includes a processing circuit, the processing circuit being configured to: configure, in response to request signalling from a user equipment, an aperiodic beam-forming reference signal relevant to a first beam group for the user equipment, wherein the first beam group is determined by a base station according to channel state information periodically fed back by the user equipment; generate downlink control information, so as to indicate that the user equipment feeds back beam selection information according to the aperiodic beam-forming reference signal; determine, according to the beam selection information, one or a plurality of candidate beams and one or a plurality of corresponding second pre-coding codebooks; and determine an effective pre-coding codebook based on the one or multiple second pre-coding codebooks.

Embodiments herein relate to a method performed by wireless device for applying a Channel State Information, CSI, filtering in a wireless communication network. The wireless device determines a recommended CSI filtering based on measurements of one or more received reference signals from a radio network node. The wireless device transmits, to the radio network node, a first indication of the determined recommended CSI filtering. The wireless device receives, from the radio network node or another radio network node, a first configuration of CSI filtering; and uses the received first configuration for applying CSI filtering.

An electronic device at a base station end includes a processing circuit, the processing circuit being configured to: configure, in response to request signalling from a user equipment, an aperiodic beam-forming reference signal relevant to a first beam group for the user equipment, wherein the first beam group is determined by a base station according to channel state information periodically fed back by the user equipment; generate downlink control information, so as to indicate that the user equipment feeds back beam selection information according to the aperiodic beam-forming reference signal; determine, according to the beam selection information, one or a plurality of candidate beams and one or a plurality of corresponding second pre-coding codebooks; and determine an effective pre-coding codebook based on the one or multiple second pre-coding codebooks.

Using channel state information (CSI), e.g., rank information, precoding matrix index, etc., that is reported periodically by a user equipment, a complexity of reporting of aperiodic CSI reporting can be reduced, by reducing a search space of a codebook used for the aperiodic CSI reporting, when the UE is configured with periodic and aperiodic CSI reporting. A periodic configuration of a mobile device is facilitated for transmissions of channel state data periodically, and, in response to sending a reference signal, first channel state data of the channel is received according to the periodic configuration. Based on the first channel state data, an aperiodic configuration of the mobile device can be facilitated for transmissions of the channel state data aperiodically according to aperiodic requests received by the mobile device. Then, second channel state data can be received by the network device according to the aperiodic configuration.