Default aperiodic channel state information reference signal beam for same numerology triggering

A method of wireless communication at a user equipment (UE), comprising:

• receiving downlink control information (DCI) in a physical downlink control channel (PDCCH), the DCI triggering reception of aperiodic (AP) channel state information (CSI) reference signal (RS) (CSI-RS) and reporting of CSI, the PDCCH having a first numerology and the AP CSI-RS having a second numerology;
• determining, when a control resource set (CORESET) is configured on an active bandwidth part (BWP) of a serving cell for receiving the AP CSI-RS and when the first numerology is the same as the second numerology, a default AP CSI-RS beam for receiving the AP CSI-RS based on a beam used for receiving the CORESET with a lowest identifier (ID) in a latest monitored slot of the active BWP of the serving cell;
• and
• determining, otherwise when the first numerology is the same as the second numerology, the default AP CSI-RS beam for receiving the AP CSI-RS based on a quasi-co-located (QCL) assumption of a physical downlink shared channel (PDSCH) transmission control indicator (TCI) state with a lowest ID on the active BWP of the serving cell for receiving the AP CSI-RS.

An apparatus for wireless communication at a base station, comprising:

• a memory;
• and
• at least one processor coupled to the memory and configured to:
• transmit, to a user equipment (UE), downlink control information (DCI) in a physical downlink control channel (PDCCH), the DCI triggering reception of aperiodic (AP) channel state information (CSI) reference signal (RS) (CSI-RS) and reporting of CSI, the PDCCH having a first numerology and the AP CSI-RS having a second numerology;
• and
• transmit, to the UE, the AP CSI-RS, the first numerology being the same as the second numerology, wherein a scheduling offset between a last symbol of the PDCCH carrying the triggering DCI and a first symbol of the AP CSI-RS is smaller than a beam-switch-timing threshold reported by the UE.