Methods, apparatus and systems are disclosed. One representative method implemented by a wireless transmit/receive unit includes determining a first beamforming matrix; sending, to a network entity, an indication of the first beamforming matrix; and receiving, from the network entity, an indication of a second beamforming matrix determined by the network entity from at least the first beamforming matrix for beamforming data for transmission.

A communication device for providing a channel state information, CSI, feedback in a wireless communication system includes a transceiver to receive, from a transmitter a radio signal via a time-variant, frequency-selective MIMO channel, the radio signal including downlink reference signals according to a reference signal configuration including a number of antenna ports, and downlink signals including the reference signal configuration; and a processor. The processor estimates an explicit CSI in the frequency domain using measurements on the downlink reference signals on the radio channel, selects a Doppler-delay precoder matrix (W) for a composite Doppler-delay-beam three-stage precoder, calculates either one or more of a channel quality indicator, CQI, and/or a precoder matrix indicator, PMI, and/or a rank indicator, RI, and reports to the transmitter the CSI feedback including either one or more of the CQI, and/or the PMI and/or the RI.

Provided are a method and an apparatus for reporting channel state information (CSI) by a user equipment in a wireless communication system. According to the present invention, the user equipment may receive configuration information related with the CSI from a base station and measure the CSI based on the configuration information. Thereafter, the user equipment includes reporting the CSI to the base station and the CSI includes a rank indicator (RI), a channel quality indicator (CQI), and an indicator indicating the number of amplitude coefficients other than 0 and the second part includes a precoding matrix indicator (PMI).

A method for a user equipment (UE) to report channel state information in a wireless communication system is disclosed. The method comprises if a plurality of bandwidth parts (BWPs) is configured for a reporting of the channel state information, constructing the channel state information based on at least one representative channel state information element per each bandwidth part, and reporting the channel state information to a base station, wherein the channel state information includes first channel state information including enhanced wideband per BWP (eWB) commonly related to channel state information of the plurality of bandwidth parts, and second channel state information related to channel state information of each bandwidth part included in the plurality of bandwidth parts.

Apparatuses and methods for precoding matrix indicator (PMI)-based data beam nulling with a channel state information (CSI) report. An apparatus includes a transceiver configured to communicate via a wired or wireless communication medium and a processor coupled to the transceiver. The processor is configured to identify restricted PMI beams in a nulling direction for supported ranks; receive, via the transceiver from a user equipment (UE), a CSI report including a rank, a PMI, and channel quality indicator (CQI) feedback; and determine whether the reported PMI is restricted. The processor is further configured to select an alternative PMI among a number of unrestricted PMIs for the reported rank; boost a reported CQI if a reduced transmit power is configured; and select a modulation coding scheme (MCS) and generate a precoder for a data beam based on at least one of: the CSI report, the alternative PMI, and the boosted CQI.

Methods, apparatus and systems are disclosed. One representative method implemented by a wireless transmit/receive unit includes determining a first beamforming matrix; sending, to a network entity, an indication of the first beamforming matrix; and receiving, from the network entity, an indication of a second beamforming matrix determined by the network entity from at least the first beamforming matrix for beamforming data for transmission.

A network node is configured to receive and/or estimate respective precoder information for a plurality of wireless devices. A respective orthogonal projection matrix is determined for each of the plurality of WDs based at least in part on the precoder information of all other WDs of the plurality of WDs. A respective modified precoder matrix is determined for each of the plurality of WDs based at least in part on the respective orthogonal matrix and precoder information for each WD of the plurality of WDs. A composite precoder matrix is determined based at least in part on the modified precoder matrices for each of the plurality of WDs. A transmission beam shape is then determined for use in transmission to at least one of the plurality of WDs based on the composite precoder matrix.

Enhanced channel state information (CSI) feedback is disclosed for full dimensional multiple input, multiple output (FD-MIMO) operations. In one aspect, a single CSI process is defined that is configured with an azimuth and elevation CSI-reference signal (RS) ports. A user equipment (UE) will send a precoding matrix indictor (PMI) report including a precoding matrix indicator (PMI) for the azimuth ports and a PMI for the elevation ports. One of the PMIs is assigned a low rank. The base station will use the two PMIs to create a whole channel precoding matrix. In another aspect, a single CSI process is configured having a plurality of CSI-RS resources. The UE generates channel measurement information for each of the CSI-RS resources, but only sets a CSI report to the base station of a subset of the total number of resources.

The present disclosure relates to a method, performed by a user equipment (UE), for reporting channel state information (CSI) in a wireless communication system and an apparatus therefor. According to the present disclosure, the UE receives a channel state information reference signal (CSI-RS) from a base station through a multiple antenna port; and reports the CSI to the base station, wherein the CSI includes a precoding matrix indicator for a codebook generated by linear combination, wherein the codebook is generated based on a specific parameter set, and wherein the specific parameter set is differently set/applied based on at least one of a rank value or at least one layer index of a specific rank.

A communication device according to an embodiment is capable of communicating with another communication device via a first network and a second network each transmitting radio signal data by different communication methods. The communication device includes: a first communicator capable of communicating with another communication device via the first network; a second communicator capable of communicating with another communication device via the second network; a delay parameter acquirer to acquire a delay parameter of the first network; and a delay parameter reflector to reflect the delay parameter of the first network acquired by the delay parameter acquirer on a delay parameter of the second network.