Abstract: A method is disclosed for multi-user multiple-input multiple-output (MU-MIMO) operation of an access node serving a plurality of user devices. The method comprises acquiring a speed category for a user device of the plurality of user devices and controlling the MU-MIMO operation in relation to the user device based on the speed category. In some embodiments, controlling the MU-MIMO operation in relation to the user device based on the speed category comprises one or more of: controlling reference signal transmission for the user device based on the speed category and controlling MU-MIMO group affiliation of the user device based on the speed category. In some embodiments, controlling reference signal transmission for the user device based on the speed category comprises controlling a duration of a time interval between subsequent reference signal transmissions for the user device based on the speed category. Corresponding apparatus and network node are also disclosed.

Abstract: A method is disclosed for multi-user multiple-input multiple-output (MU-MIMO) operation of an access node serving a plurality of user devices. The method comprises acquiring a speed category for a user device of the plurality of user devices and controlling the MU-MIMO operation in relation to the user device based on the speed category. In some embodiments, controlling the MU-MIMO operation in relation to the user device based on the speed category comprises one or more of: controlling reference signal transmission for the user device based on the speed category and controlling MU-MIMO group affiliation of the user device based on the speed category. In some embodiments, controlling reference signal transmission for the user device based on the speed category comprises controlling a duration of a time interval between subsequent reference signal transmissions for the user device based on the speed category. Corresponding apparatus and network node are also disclosed.

Abstract: A method for wireless communication is disclosed, wherein an access node is configured to transmit signals using beamforming to a user device, wherein transmitting signals using beamforming comprises transmitting signals using a selected beam of a plurality of available beams, and wherein beam tracking comprises measurements by the user device on a candidate set of beams of the plurality of available beams for beam selection. The method comprises predicting a future trajectory for the user device, and determining the candidate set of beams based on the predicted future trajectory. In some embodiments, determining the candidate set of beams based on the predicted future trajectory comprises giving preference to available beams covering the predicted future trajectory.

Abstract: A method for wireless communication is disclosed, wherein an access node is configured to transmit signals using beamforming to a user device, wherein transmitting signals using beamforming comprises transmitting signals using a selected beam of a plurality of available beams, and wherein beam tracking comprises measurements by the user device on a candidate set of beams of the plurality of available beams for beam selection. The method comprises estimating at least one of a distance from the access node to the user device and a velocity parameter of the user device, and adjusting one or more of a beam tracking measurement frequency, a beam tracking measurement periodicity, the beam tracking measurement period, and a beam tracking measurement interval based on at least one of the estimated distance from the access node to the user device and the estimated velocity parameter of the user device.