Wireless devices may receive channel state information (CSI) measurement resources for a plurality of cells, including cells of a first transmission point and cells of a second transmission point. The wireless device may measure CSI for each cell, and may quantize the measured CSI jointly across the cells. The wireless device may send the jointly quantized CSI to a base station, and the jointly quantized CSI may be used in communications via the first transmission point and the second transmission point.

Disclosed are a signal method for a CoMP operation in a wireless communication system and a device therefor. Particularly, the signaling method for a CoMP operation between base stations in a wireless communication system comprises a step of transmitting, by a first base station, first CoMP information to a second base station, wherein: the first CoMP information includes CoMP hypothesis set information which is a collection of CoMP hypothesis information for one or more cells, benefit metric information associated with the CoMP hypothesis set, start system frame number (SFN) information, and start subframe number information; the CoMP hypothesis is hypothetical physical resource block (PRB) specific resource allocation information for one cell; the start SFN information indicates a start wireless frame number of the first CoMP information; and the start subframe number information can indicate a start subframe number of the first CoMP information.

Certain aspects of the present disclosure provide techniques for a basis report for compressed channel state information (CSI) feedback with a non-contiguous subband configuration. A method for wireless communication by a user equipment (UE) includes receiving a CSI report configuration configuring the UE for reporting precoding matrix information including, a plurality of selected beams, a frequency domain compression matrix for each of the beams at each of a plurality of taps in the time domain, and a subset of a plurality of linear combination coefficients associated with the frequency domain compression matrices and beams. The UE receives a configuration of non-contiguous frequency resources for CSI reporting. The UE may perform frequency domain compression of the precoding matrix information using a truncated frequency domain compression matrix or performing separate frequency domain compression of the precoding matrix information for each set of contiguous frequency resources.

Apparatuses, methods, and systems are disclosed for preparing channel state information (“CSI”). One apparatus includes a processor and a transceiver configured to communicate with a base unit over a radio access network using at least one transmission layer and determining a total number of non-zero coefficients over a set of layers. The processor determines an indication of the total number of non-zero coefficients, where determining the indication of the total number of non-zero coefficients comprises encoding the total number of non-zero coefficients by selecting a codeword from a plurality of candidate codewords. The processor prepares CSI, where the CSI comprises the indication of the total number of non-zero coefficients and the transceiver transmits the CSI to the base unit.

A method for uplink multiuser data transmission and a system for uplink multiuser multiple input multiple output are provided. The method includes: sending, by an access point (AP), indication information to at least two stations (STAs), wherein the indication information is used for indicating that the at least two STAs perform an uplink multiuser data transmission; receiving, by the AP, uplink data sent by the at least two STAs through channels from the at least two STAs to the AP, respectively; and demodulating, by the AP, the uplink data sent by the at least two STAs using receiving beams corresponding to pre-estimated channels from the at least two STAs to the AP, respectively.

Certain aspects of the present disclosure provide techniques for reporting channel state information (CSI) with spatial and time domain compression.

The present application discloses a method of channel estimation based on precoding granularity of control resource set, which is applied to a user equipment with control resource set (CORESET) configured in a non-RRC manner. The method includes: determining precoding granularity according to a determination mode among a plurality of determination modes; performing channel estimation according to the precoding granularity. The plurality of determination modes includes: determining the precoding granularity according to a resource element group (REG) bindle size in frequency domain, determining the precoding granularity according to the number of consecutive resource blocks (RBs) in frequency domain of the CORESET, and determining the precoding granularity according to network configuration information. According to the present application, the precoding granularity of the control resource set configured in a non-RRC manner can be determined, so that the user equipment can determine the precoding granularity before the RRC connection is established, and then perform channel estimation.

The present disclosure relates to methods and devices for wireless communication of an apparatus, e.g., a UE and/or a base station. In one aspect, the apparatus may measure a plurality of beams from a base station or a UE, the plurality of beams corresponding to a plurality of subbands of a wideband channel. The apparatus may also determine whether the plurality of beams include one or more candidate beam groups for each subband of the plurality of subbands. Additionally, the apparatus may transmit, upon determining that the plurality of beams include one or more candidate beam groups for at least one subband of the plurality of subbands, an indication of the one or more candidate beam groups for the at least one subband of the plurality of subbands.

Certain aspects of the present disclosure provide techniques for channel state information (CSI) reporting with frequency domain (FD) compression. A method that can be performed by a user equipment (UE) includes determining the size of the intermediate set based on one or more parameters included in the CSI report configuration, determining one or more FD bases for each layer based on the intermediate set, wherein the one or more FD bases are characterized by an M value indicative of a number of the one or more FD bases and based on the CSI report configuration, and reporting the one or more FD bases for each layer based on the size of the intermediate set.

A method in a user equipment, UE, for reporting channel state information, CSI, to a network includes determining a number of subbands of a bandwidth part, BWP, to report CSI. The method further includes determining a CSI computation time including a CSI computation delay requirement. The method further includes performing CSI estimation for a plurality of the number of subbands based on the CSI computation time. The method further includes reporting the CSI report for at least one of the number of subbands. Analogous UEs, computer programs and computer program products are also provided.