Channel state information (CSI) is reduced for a multi input multi output (MIMO) channel, in which feeding back a part of the CSI matrix is sufficient to align interference in a MIMO network. A feedback dimension quantifies a cost of the CSI feedback of the interference in the MIMO network. A feedback profile is determined that achieves a tradeoff between degrees of freedom, antenna resources and the cost of the feedback. The feedback profile parameterizes a feedback function, which determines how the CSI matrices are fed back to the transmitter. The precoders of the network are adaptive to only the partial CSI knowledge at the transmitter.

Embodiments of systems and methods for flexible Channel State Information (CSI) feedback in a cellular communications network are disclosed. In some embodiments, a base station configures a wireless device with a set of CSI-RS resources, dynamically configures a CSI-RS resource from the set of CSI-RS resources for measurement, and receives a CSI report from the wireless device determined from the CSI-RS resource dynamically configured for measurement. In this manner, the base station is enabled to dynamically configure and re-configure the CSI-RS resource(s) for measurement by the wireless device, which in turn provides flexible CSI feedback that is particularly well-suited for embodiments in which the base station transmits beamformed CSI-RS.

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 contemplate methods and systems for determining and communicating channel state information (CSI) for one or more transmission points (or CSI reference signal resources). Embodiments further contemplate determining transmission states may include applying at least one CSI process for channel state information (CSI) reporting. Embodiments also contemplate aperiodic and/or periodic reporting of one or more report types (e.g., rank indicator (RI)) of CSI, perhaps based on one or more reporting modes that may be configured for each of the one or more CSI process.

A method of Coordinated Multipoint (CoMP) communication between a base station having a plurality of points with at least one user equipment (UE). At least one UE receives at least one transmission from the base station having the plurality of points. This UE measures downlink channel state information for each of the plurality of points including a rank indicator (RI), a precoding matrix indicator (PMI) and a channel quality indicator (CQI). This UE transmits the downlink channel state information in an uplink feedback channel to the base station.

A Virtual Antenna Mapping (VAM) method of a base station and a transmission apparatus equipped with M physical antennas and Q Transceiver Units (TXRUs) are provided. The method includes transmitting Reference Signals (RSs) arranged differently according to respective VAM patterns to a terminal in a transmission mode supporting N logical antennas; receiving a feedback including information regarding a VAM pattern selected as a result of channel measurement with respect to the RSs transmitted according to the VAM pattern from the terminal; and transmitting a signal to the terminal through the M physical antennas by applying the selected VAM pattern, wherein the selected VAM pattern maps N data streams corresponding to the N logical antennas to the M physical antennas through the Q TXRUs.

Provided are a method and device for feeding back and receiving channel information. The method comprises: determining a candidate resource set, selecting M resources from the candidate resource set, and transmitting at least one of indication information or channel state information of the selected M resources to a first communication node, where M is a positive integer; a selection criterion for selecting the M resources from the candidate resource set is determined in at least one of following manners: a selection criterion or a selection criterion set is agreed with the first communication node, and a selection criterion or a selection criterion set is obtained according to received indication information transmitted by the first communication node, and the selection criterion set comprises at least one selection criterion.

The present specification provides a method for reporting aperiodic channel state information (CSI) in a wireless communication system. Specifically, a method performed by the terminal comprises a step of receiving configuration information with respect to at least one reporting setting from a base station; a step of receiving control information indicating a measurement resource (MR) associated with the aperiodic CSI report from the base station; a step of computing aperiodic CSI on the basis of a particular reporting setting associated with the control information; and a step of transmitting the aperiodic CSI to the base station through a physical uplink control channel (PUCCH).

Wireless communication techniques for utilizing beam-specific RSSI and CO in NR-U wireless communication are discussed. A UE may receive from a base station a first set of one or more RSSI measurement configuration parameters associated with a first reception beam as well as a second set of one or more RSSI measurement configuration parameters associated with a second reception beam. The second reception beam may be different than the first reception beam. The UE may transmit a report including at least one of a first indication of one or more RSSI measurements performed using the first reception beam based, at least in part, on the first set of one or more RSSI measurement configuration parameters or a second indication of one or more other RSSI measurements performed using the second reception beam based, at least in part, on the second set of one or more RSSI measurement configuration parameters.

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.