A base station may transmit to a device an indication of codebook subset restriction (CBSR), which includes at least a restriction on a frequency basis. The device may receive the indication of CBSR, and may transmit to the base station channel state information (CSI) according to the received indication of CBSR. The indication of CBSR may also include a restriction on a spatial basis and restrict the device from reporting the CSI based on a subset of the frequency basis in addition to the spatial basis per configuration of the base station. The indication of CBSR may include a separately configured maximum allowed amplitude of a weighting coefficient for the spatial basis and the frequency basis, where the weighting coefficient is associated with a column vector of a precoding matrix used by the base station and the device. The number of frequency bases and the frequency compression units may be determined based on a number of different criteria, for example the number of antennas, the number of subbands, etc.

One embodiment provides an electronic device comprising an antenna. The electronic device comprises: an array antenna including a plurality of antenna elements; a transceiver circuit operatively coupled to the array antenna and configured to control a signal of a millimeter wave band applied to the array antenna; and a processor operatively coupled to the transceiver circuit and configured to control the transceiver circuit. The processor can emit a signal to a second electronic device through one antenna element of the plurality of antenna elements, select an optimum antenna element on the basis of a data rate in the second electronic device which has received the signal, and communicate with the second electronic device through the selected antenna element.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive, from a base station, a downlink message via multiple receive antennas including a first group of receive antennas associated with a first antenna panel and a second group of receive antennas associated with a second antenna panel. The UE may generate two or more CSI reports based on receiving the downlink message, where each CSI report is associated with at least one of the first antenna panel or the second antenna panel. The UE may select at least one of the two or more CSI reports to transmit to the base station. In some examples, the UE may receive (e.g., via control signaling) a CSI report configuration and may select the at least one CSI report for transmission based on the CSI report configuration.

A method of channel state information (CSI) report can include receiving a CSI report configuration at a user equipment (UE) from a base station. The CSI report configuration indicates CSI reference signal (CSI-RS) resources configured for transmitting CSI-RSs from multiple transmission and reception points (TRPs). An CSI-RS measurement process can be performed at the UE based on the CSI-RSs transmitted from the multiple TRPs using the CSI-RS resources indicated by the CSI report configuration. A CSI report can be transmitted from the UE to the base station based on the CSI report configuration. The CSI report includes information of one or more phase differences or one or more amplitude differences among the CSI-RSs transmitted from the multiple TRPs.

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.

Aspects of the subject disclosure may include, for example, determining a coherence block for each user equipment (UE) of a plurality of UEs being served by the first cell, resulting in a plurality of coherence blocks, responsive to the determining, identifying a smallest coherence block from the plurality of coherence blocks, identifying a pilot sequence length based on the smallest coherence block, determining a plurality of orthogonal pilot sequences based on the identifying the pilot sequence length, designating, from the plurality of orthogonal pilot sequences, a first group of orthogonal pilot sequences for use in the first cell, and distributing, to each neighboring cell of a plurality of neighboring cells adjacent to the first cell, a respective group of orthogonal pilot sequences from a remainder of the plurality of orthogonal pilot sequences, to prevent pilot contamination between the first cell and the plurality of neighboring cells. Other embodiments are disclosed.

The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.

A method for a channel state information (CSI) feedback comprises receiving CSI feedback configuration information for the CSI feedback including a spatial channel information indicator based on a linear combination (LC) codebook, wherein the spatial channel information comprises at least one of a downlink channel matrix, a covariance matrix of the downlink channel matrix, or at least one eigenvector of the covariance matrix of the downlink channel matrix; deriving the spatial channel information indicator using the LC codebook that indicates a weighted linear combination of a plurality of basis vectors or a plurality of basis matrices as a representation of at least one of a downlink channel matrix, a covariance matrix of the downlink channel matrix, or at least one eigenvector of the covariance matrix of the downlink channel matrix; and transmitting over an uplink channel, the CSI feedback including the spatial channel information indicator.

A method and network node for timing error estimation and compensation for Fifth Generation (5G) New Radio (NR) downlink (DL) systems with uncalibrated antennas are provided. According to one aspect, a method in a network node includes transmitting a first Channel State Information Reference Signal (CSI-RS) having a first timing compensation and transmitting a second CSI-RS having a second timing compensation, receiving a CSI-RS resource indicator (CRI) in a CSI report from a wireless device (WD), and determining from the CRI which of the first and second timing compensation results in a greater spectrum efficiency.