Selecting a phase tracking reference signal demodulation reference signal association bitfield length

An apparatus for wireless communication at a user equipment (UE), comprising:

• one or more memories;
• and
• one or more processors, coupled to the one or more memories, configured to cause the UE to:
• derive a first potential length for a phase tracking reference signal demodulation reference signal (PTRS-DMRS) association bitfield based at least in part on a simultaneous transmissions with multiple panels (STxMP) configuration;
• derive a second potential length for the PTRS-DMRS association bitfield based at least in part on a single transmit receive point (sTRP) configuration;
• select a finalized length for the PTRS-DMRS association bitfield as a maximum length of the first potential length and the second potential length;
• and
• communicate with a network node based at least in part on recovering information from downlink control information (DCI) based at least in part on the finalized length of the PTRS-DMRS association bitfield.

A method of wireless communication performed by a network node, comprising:

• deriving a first potential length for a phase tracking reference signal demodulation reference signal (PTRS-DMRS) association bitfield based at least in part on a simultaneous transmissions with multiple panels (STxMP) configuration;
• deriving a second potential length for the PTRS-DMRS association bitfield based at least in part on a single transmit receive point (sTRP) configuration;
• selecting a finalized length for the PTRS-DMRS association bitfield based at least in part on the first potential length and the second potential length, the selecting comprising:
• selecting, as the finalized length, a maximum length of the first potential length and the second potential length;
• and
• transmitting downlink control information (DCI) using a DCI configuration that is associated with the finalized length of the PTRS-DMRS association bitfield.