Methods and apparatuses for CSI reporting mechanisms are provided. A user equipment (UE) includes a transceiver and a processor operably connected to the transceiver. The transceiver is configured to receive information indicating a channel state information reference signal (CSI-RS) resource configuration, uplink-related downlink control information (DCI), and a CSI-RS associated with a selected CSI-RS resource in a same subframe as the uplink-related DCI. The processor configured to determine, in response to a CSI request included in the uplink-related DCI, an aperiodic CSI in reference to the CSI-RS. The transceiver is further configured to report the aperiodic CSI by transmitting the aperiodic CSI 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, sub-channel 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 panels, an antenna array of the second network device includes N panels, the channel between the first network device and the second network device includes the NM sub-channels, M is a positive integer that is greater than or equal to 2, N is and N is a positive integer, M and N are not to be 1 at the same time, and the M panels and the N panels each includes at least two antennas; generating channel information of the channel between the first network device and the second network device according to the sub-channel channel information of the NM sub-channels.

A method for transmitting and receiving a signal based on a codebook in a multi-antenna wireless communication and a device therefor are disclosed. Specifically, a method for transmitting and receiving a signal by a UE on the basis of a codebook in a 2-dimensional multi-antenna wireless communication system includes: receiving a channel state information-reference signal (CSI-RS) from an eNB through multiple antenna ports; and reporting channel state information to the eNB, wherein the channel state information includes a precoding matrix indicator (PMI), the PMI includes a first PMI for selecting a precoding matrix set from the codebook and a second PMI for selecting a precoding matrix from the precoding matrix set, pairs of indexes of a first dimension and indexes of a second dimension of precoding matrices belonging to the precoding matrix set are (x,y), (x+2,y), (x,y+1) and (x+1,y+1), and x and y are integers which are not negative numbers.

Disclosed are a method for transmitting and receiving channel state information in a multi-antenna wireless communication system, and an apparatus therefor. Particularly, a method by which user equipment (UE) reports channel state information in a two-dimensional multi-antenna wireless communication system comprises the steps of: receiving, from a base station, a channel state information reference signal (CSI-RS) through a multi-antenna port; and reporting the channel state information to the base station, wherein a plurality of codewords, which are used for generating a pre-coding matrix selected by the UE in a codebook for reporting the channel state information, are specified by the channel state information and, after power coefficients are applied to each of the plurality of codewords, the pre-coding matrix can be generated based on a linear combination of the plurality of codewords to which the power coefficients are applied.

The disclosure pertains to a method for operating a terminal (10) in a wireless communication network, the method comprising performing reporting based on a configuration, the configuration indicating the timing of reporting of first angular transmission information and/or indicating the timing of reporting of second angular transmission information. The disclosure also pertains to related methods and devices.

A method, in a radio network node, comprises identifying, among a predetermined codebook of precoding matrix codewords, a subset of precoding matrix codewords that are not to be reported by the wireless device in channel-state-information, CSI, feedback, and transmitting, to the wireless device, a bitmap identifying the subset of precoding matrix codewords that are not to be reported by the wireless device; where each bit in the bitmap corresponds to only one combination of a first dimension index l.sub.1 and a second dimension index l.sub.2 out of the possible combinations of the first dimension index l.sub.1 and the second dimension index l.sub.2, and where the first dimension index l.sub.1 and the second dimension index l.sub.2 identify a two-dimensional beam, the two-dimensional beam being defined by a vector of complex numbers comprised within at least one column of a precoding matrix codeword in the codebook.

A communication device for providing an explicit channel state information, CSI, feedback in a wireless communication system includes a transceiver to receive, from a transmitter a radio signal via a radio time-variant frequency MIMO channel, the radio signal including downlink reference signals according to a reference signal configuration, and downlink signals including the reference signal configuration, and a processor. The processor estimates the CSI using measurements on the downlink reference signals of the radio channel according to the reference signal configuration over one or more time instants/slots, constructs a frequency-domain channel tensor using the CSI estimate, performs a higher-order principal component analysis, HO-PCA, on the channel tensor, identifies a plurality of dominant principal components of the channel tensor, thereby obtaining a compressed channel tensor, and reports to the transmitter the explicit CSI including the dominant principal components of the channel tensor.

A method for operating a user equipment (UE) comprises receiving configuration information for at least one channel state information reference signal (CSI-RS) resource that comprises P.sub.CSIRS CSI-RS ports; receiving configuration information for channel state information (CSI) feedback that is based on Q precoding dimensions, wherein: there is a mapping between the P.sub.CSIRS CSI-RS ports and the Q precoding dimensions, and P.sub.CSIRS?Q; measuring the P.sub.CSIRS CSI-RS ports; determining a measurement for the Q precoding dimensions based on the mapping and the measurement for the P.sub.CSIRS CSI-RS ports; determining a CSI feedback based on the measurement for the Q precoding dimensions; and transmitting, over an uplink (UL) channel, the determined CSI feedback.

The present invention discloses a channel state information (CSI) feedback method and related device for an FD MIMO system, and is configured to support the scenario in which various CSI related information needs to be fed back after a CSI measurement in an FD MIMO system. The method comprises: a terminal receives a CSI feedback configuration group indicated by a base station and configuration information for performing a CSI feedback based on the CSI feedback configuration group; and the terminal performs a CSI measurement and feedback according to the CSI feedback configuration group and the configuration information, wherein the CSI feedback configuration group comprises at least one CSI feedback configuration, and the CSI feedback configuration is a downlink signal configuration for a downlink CSI measurement and feedback.

The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). The present disclosure relates to a method and device for reporting channel state information. The method for a terminal according to the present disclosure comprises the steps of: receiving feedback configuration information from a base station; measuring a channel state using a reference signal received from the base station; and reporting channel state information using two subsamplings at a reporting time which is determined on the basis of the feedback configuration information.