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.

Methods and apparatuses for time-domain beam-sweeping are disclosed. In one embodiment, a method implemented in a wireless device (WD) includes receiving a CSI report configuration, the CSI-RS resource configuration and the CSI report configuration mapping each of a plurality of time-do-main beam sweeping CSI-RS transmissions in the configured one CSI-RS resource to a corresponding CSI report; receiving at least one of the plurality of time-domain beam sweeping CSI-RS transmissions in the configured one CSI-RS resource; and transmitting at least one CSI report according to the mapping. In another embodiment, a method in a network node includes determining a CSI-RS resource configuration for one CSI-RS resource; determining a CSI report configuration; and transmitting the plurality of time-domain beam sweeping CSI-RS transmissions in the configured one CSI-RS resource according to the mapping.

In accordance with an example embodiment of the present invention, a method comprising: selecting, by a user equipment, a subset of linear combination coefficients from a linearized two-dimensional matrix having columns of frequency domain components and rows of spatial beams components for channel state information determination, wherein the number of linear combination coefficients in the subset is less than all of the linear combination coefficients; determining indication comprising information associated with column indices of the selected subset of linear combination coefficients from the linearized two-dimensional matrix, wherein the indication excludes the index of the column with lowest index of the linearized two-dimensional matrix; determining compressed channel state information comprising locations in the linearized two-dimensional matrix of the subset of linear combination coefficients and corresponding values of the linear combination coefficients at those locations; and reporting, from the user equipment toward the base station, the compressed channel state information.

Methods, network nodes and wireless device for setting an electrical tilt of an antenna array toward a distribution of wireless devices are disclosed. According to one aspect, a method includes for each of at least one sector of an area covered by the antenna array, determining a function of precoding matrix indicators, PMIs, received from a plurality of WDs in the sector. The method includes determining a current electrical tilt angle of the sector based on the function of PMIs. The method further includes comparing a difference between the current electrical tilt angle of the sector and a previously determined electrical tilt angle of the antenna array to a first threshold, and setting the electrical tilt angle of the antenna array based on the comparison.

Disclosed are a codebook-based signal transmission and reception method in a multi-antenna wireless communication system and an apparatus therefor. Specifically, a method for transmitting or receiving a signal on the basis of a codebook by a terminal in a 2-dimensional multi-antenna wireless communication system comprises the steps of: receiving a channel state information reference signal (CSI-RS) through a multi-antenna port from a base station; and reporting channel state information to the base station, wherein the channel state information may include a precoding matrix indicator (PMI) for indicating a precoding matrix, the PMI may include a first PMI for selecting a set of precoding matrixes from the codebook and a second PMI for selecting one precoding matrix from the set of precoding matrixes.

Disclosed are a codebook-based signal transmission and reception method in a multi-antenna wireless communication system and an apparatus therefor. Specifically, a method for transmitting or receiving a signal on the basis of a codebook by a terminal in a 2-dimensional multi-antenna wireless communication system comprises the steps of: receiving a channel state information reference signal (CSI-RS) through a multi-antenna port from a base station; and reporting channel state information to the base station, wherein the channel state information may include a precoding matrix indicator (PMI) for indicating a precoding matrix, the PMI may include a first PMI for selecting a set of precoding matrixes from the codebook and a second PMI for selecting one precoding matrix from the set of precoding matrixes.

An apparatus and method for arranging a beam in a wireless communication system are provided. An electronic device includes a memory storing codebook information, a communication module operatively connected with the memory, and a processor operatively connected with the communication module and the memory. The processor is set to provide a first beam and a first beam set including beams surrounding the first beam on the basis of the codebook information, where centers of regions covered by the beams included in the first beam set substantially form an equilateral hexagon, and transceiver data by using the first beam and the first beam set.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may select a precoding matrix of orthogonal beams. The base station may precode a channel state information reference signal (CSI-RS) transmitted to a user equipment (UE) using the precoding matrix of orthogonal beams. The base station may receive, from the UE, one or more reports that indicate one or more beam indices selected from beam indices associated with the precoding matrix of orthogonal beams. Numerous other aspects are provided.

Systems and methods are disclosed herein that related to determining and using a codebook in a virtualized Active Antenna System (AAS). In some embodiments, a first radio node that is configured to communicate with a second radio node comprises a radio interface and processing circuitry configured to transform a first codebook that is in a non-virtualized antenna domain to a second codebook that is in a virtualized antenna domain based on a port to antenna mapping matrix used to transform a signal from the virtualized antenna domain to the non-virtualized antenna domain prior to transmission of the signal in a corresponding virtualized cell or sector. The processing circuitry is further configured to receive a transmit signal from the second radio node to thereby provide a received signal and perform Precoding Matrix Indication (PMI) estimation based on the received signal using the second codebook in the virtualized antenna domain.

To employ codebook design and signaling for multiple transmit antennas, a user equipment (UE) apparatus includes a processor and a transceiver operably connected to the processor. The transceiver is configured to receive configuration information for a channel state information (CSI) process, receive configuration information for a CSI reference signal (CSI-RS) resource; receive configuration information for a MIMO type; and receive a plurality of codebook parameters when the MIMO type is non-precoded. A base station (BS) apparatus for codebook design and signaling includes a transceiver and a processor operably connected to the transceiver. The processor is configured to configure a UE with a CSI process and a CSI-RS resource, configure the UE with a MIMO type, and cause the transceiver to transmit configuration information for the CSI process, the CSI-RS resource, and the MIMO type to the UE.