Algorithm for mitigation of impact of uplink/downlink beam mismatch

A method, comprising:

• implementing, separately for at least one downlink beam of a plurality of downlink beams of the access node, a reinforcement learning model, wherein a state, an action and a reward of the reinforcement learning model for a downlink beam are defined as follows:
• the state defines which of the plurality of uplink beams belong to a priority beam set for uplink reception from one or more source terminal devices for which said downlink beam is an optimal downlink beam,
• the action in a given state is defined as an addition of a new uplink beam of the plurality of uplink beams to the priority beam set, a removal of an uplink beam from the priority beam set or doing nothing, and
• the reward of taking a given action in a given state is calculated based on a change in uplink signal-to-noise ratio statistics of the one or more source terminal devices due to an action adjusted with a cost for taking the action;
• and
• calculating iteratively at least one optimal state defining at least one priority beam set using at least one reinforcement learning model based on uplink signal-to-noise ratio statistics derived or derivable from uplink reference signal received power statistics for signals measured using a plurality of uplink beams of the access node from a plurality of terminal devices and on a plurality of optimal downlink beams of the access node for transmission to said plurality of terminal devices.

A non-transitory computer readable medium encoded with program instructions that, when executed in hardware, cause the hardware to perform:

• implementing, separately for at least one downlink beam of a plurality of downlink beams of an access node, a reinforcement learning model, wherein a state, an action and a reward of the reinforcement learning model for a downlink beam are defined as follows:
• the state defines which of the plurality of uplink beams belong to a priority beam set for uplink reception from one or more source terminal devices for which said downlink beam is an optimal downlink beam,
• the action in a given state is defined as an addition of a new uplink beam of the plurality of uplink beams to the priority beam set, a removal of an uplink beam from the priority beam set or doing nothing, and
• the reward of taking a given action in a given state is calculated based on a change in uplink signal-to-noise ratio statistics of the one or more source terminal devices due to an action adjusted with a cost for taking the action;
• and
• calculating iteratively at least one optimal state defining at least one priority beam set using at least one reinforcement learning model based on uplink signal-to-noise ratio statistics derived or derivable from uplink reference signal received power statistics for signals measured using a plurality of uplink beams of the access node from a plurality of terminal devices and on a plurality of optimal downlink beams of the access node for transmission to said plurality of terminal devices.