A method, by which a terminal transmits channel state information in a wireless communication system, comprises a step for performing one integrated CSI process, the step for performing one integrated CSI process comprising the steps of: receiving, from a base station, a first channel state information-reference signal related to a CSI-RS resource which is not pre-coded; reporting, to the base station, a first pre-coding matrix indicator derived on the basis of the first CSI-RS; receiving, from the base station, a second CSI-RS related to one CSI-RS resource of a beam-formed CSI-RS type; and reporting, to the base station, a second rank indicator/channel quality indicator/second PMI derived on the basis of the second CSI-RS.

A method for operating an access node includes sending, to a user equipment (UE), a frequency domain density reduction rate indicator and a frequency shift index indicator for one or more channel state indicator reference signal (CSI-RS) resources, wherein the frequency domain density reduction rate indicator indicates a number of physical resource blocks (PRBs) skipped between successive CSI-RS transmissions and the frequency shift index indicator indicates a shift of a CSI-RS starting PRB.

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.

A user apparatus that perform communication with a base station in a mobile communication system is disclosed. The user apparatus includes a transmitter that transmits capability information of the user apparatus to a base station, a receiver that receives configuration information from the base station, and a processor that determines a bit width of a rank indicator based on a maximum number of Multiple-Input Multiple-Output (MIMO) layers. Further, the configuration information received from the base station includes a parameter indicating a transmission mode and the maximum number of MIMO layers.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine to report first channel state information (CSI), wherein the first CSI is associated with a parameter that indicates a priority of the first CSI. The UE may prioritize the first CSI over a second CSI based at least in part on the parameter. The UE may transmit an indication of the first CSI and may drop the second CSI based at least in part on prioritizing the first CSI over the second CSI. Numerous other aspects are provided.

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.

Coordinate multi-point (CoMP) transmission is facilitated by resolving collisions between feedback reporting. Based upon the conditions within the network, collision resolution may be by dropping a channel report during a subframe, multiplexing channel reports from a plurality of user equipment, compressing channel reports from a plurality of user equipment, and combined reporting, either through joint reports or by using carrier aggregation, for conditions between a user equipment and a plurality of transmission points. New signaling and reporting formats facilitate selection of a collision resolution suitable for current network conditions.

A base station device, user equipment, and a method for reporting channel state information are disclosed. The base station device receives at least one piece of aperiodic channel state information (CSI) from user equipment, where the at least one piece of aperiodic CSI corresponds to an aperiodic CSI measurement result on a first reference subframe, the aperiodic CSI measurement result on the first reference subframe is an aperiodic CSI measurement result of a first downlink subframe set, and the first reference subframe is a subframe in the first downlink subframe set. The base station device effectively receives an aperiodic channel state measurement result of the downlink subframe set.

Exemplary embodiments of the present invention relates to an apparatus and method for performing periodic CSI reporting available in a system supporting a TDD-FDD aggregation operation and an FDD-TDD aggregation operation. A periodicity and an offset for periodic reporting of channel quality indicator and precoding matrix inidcator may be determined based on the cell type of a primary serving cell for a TDD-FDD carrier aggregation and an FDD-TDD carrier aggregation.

A user apparatus configured to perform communication with a base station in a mobile communication system that supports downlink spatial multiplexing, including: transmission means configured to transmit capability information of the user apparatus to the base station; reception means configured to receive configuration information from the base station; bit width determination means configured, if a parameter indicating a transmission mode corresponding to the downlink spatial multiplexing and predetermined additional information are received as the configuration information, to determine a bit width of a rank indicator based on the predetermined additional information.