A wireless device may support a plurality of channel state information (CSI) processes. The wireless device may send an indication of a number of supported CSI processes to a first base station. The first base station may send to the wireless device a handover command, instructing the wireless device to handover to a second base station. The handover command may comprise configuration parameters for CSI processes associated with the second base station. The configuration parameters may be based on the number of CSI processes supported by the wireless device.

Methods, apparatus, and systems for wireless communications are disclosed. A first base station may receive one or more message from a second base station. The messages may include downlink beamforming information elements for a downlink cell. Each downlink beamforming information element may be associated with a respective group of resource blocks of a plurality of groups of resource blocks in the downlink cell. The first base station may select a first beamforming codeword for at least one group of resource blocks of the plurality of groups of resource blocks based on the downlink beamforming information associated with the at least one group of resource blocks. The first base station may transmit, to a wireless device, signals on the at least one group of resource blocks employing the first beamforming codeword.

Aspects presented herein may enable a receiving device to receive high frequency signals with a simpler receiver to reduce the overall complexity and cost associated with the receiver. In one aspect, an apparatus receives a reference signal from a second wireless device. The apparatus measures amplitude and phase of the reference signal relative to a set point. The apparatus transmits channel flattening information in a precoding feedback to the second wireless device, the precoding feedback including at least a difference between the amplitude of the reference signal and the set point for a sub-band.

Aspects presented herein may enable a receiving device to receive high frequency signals with a simpler receiver to reduce the overall complexity and cost associated with the receiver. In one aspect, an apparatus receives a reference signal from a second wireless device. The apparatus measures amplitude and phase of the reference signal relative to a set point. The apparatus transmits channel flattening information in a precoding feedback to the second wireless device, the precoding feedback including at least a difference between the amplitude of the reference signal and the set point for a sub-band.

Methods, apparatus, and systems for wireless communications are disclosed. A first base station may receive one or more message from a second base station. The messages may include downlink beamforming information elements for a downlink cell. Each downlink beamforming information element may be associated with a respective group of resource blocks of a plurality of groups of resource blocks in the downlink cell. The first base station may select a first beamforming codeword for at least one group of resource blocks of the plurality of groups of resource blocks based on the downlink beamforming information associated with the at least one group of resource blocks. The first base station may transmit, to a wireless device, signals on the at least one group of resource blocks employing the first beamforming codeword.

Aspects described herein relate to wireless communications. According to some aspects, a first base station may coordinate with a second base station to select beamforming codewords. The first base station may receive an index indicating beamforming codewords used by a second base station. The first base station may select a beamforming codeword for use in transmitting signals to a wireless device based on the beamforming codeword indicated by the second base station.

Various embodiments disclosed herein provide for a base station device that can determine which layers should be mapped to codewords in a multi-layer, multi-antenna transmission. The base station device can transmit reference signals to a user equipment device, with each reference signal associated with a respective codeword to layer mapping combination, and the user equipment can send channel state information associated with each reference signal back to the base station device, and the base station device can rank each combination in terms of spectral efficiency or capacity and/or throughput. The base station device can inform the user equipment of the ranked combinations by sending a bit map with the ranked combinations to the user equipment device.

Embodiments of the present disclosure relate to a method, device and computer readable medium for user selection for MU-MIMO communications. In example embodiments, the method comprises for a set of candidate terminal devices, performing scheduling by: obtaining a set of received signals; determining a set of measurements for relevance among the candidate terminal devices based at least on the set of received signals and channel estimation for the set of candidate terminal devices; determining a maximum measurement in the set of measurements; and updating the set of candidate terminal devices by removing a candidate terminal device associated with the maximum measurement from the set of candidate terminal devices.

A wireless device may support a plurality of channel state information (CSI) processes. The wireless device may send an indication of a number of supported CSI processes to a first base station. The first base station may send to the wireless device a handover command, instructing the wireless device to handover to a second base station. The handover command may comprise configuration parameters for CSI processes associated with the second base station. The configuration parameters may be based on the number of CSI processes supported by the wireless device.

A wireless device may support a plurality of channel state information (CSI) processes. The wireless device may send an indication of a number of supported CSI processes to a first base station. The first base station may send to the wireless device a handover command, instructing the wireless device to handover to a second base station. The handover command may comprise configuration parameters for CSI processes associated with the second base station. The configuration parameters may be based on the number of CSI processes supported by the wireless device.