Co-scheduled interference UE presence signaling and modulation order detection

A system comprising:

• an apparatus;
• at least one processor;
• and
• at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to:
• receive, from a network node, a configuration for one or more resource elements having zero power;
• receive downlink control information, wherein the downlink control information comprises an aperiodic indication for triggering resource elements having zero power;
• determine a number of co-scheduled user equipments in a physical downlink shared channel based on the following:
• an index associated with the one or more resource elements, a number of the one or more resource elements, and a number of the one or more resource elements triggered with the aperiodic indication;
• determine that the number of co-scheduled user equipments comprises two co-scheduled user equipments;
• for each of the two co-scheduled user equipments:
• detect at least one frequency domain resource allocation for the co-scheduled user equipment;
• detect at least one demodulation reference signal port for the co-scheduled user equipment;
• determine a frequency domain resource allocation for the co-scheduled user equipment based on the at least one detected frequency domain resource allocation and the number of co-scheduled user equipments;
• determine a demodulation reference signal port for the co-scheduled user equipment based on the at least one detected demodulation reference signal port and the number of co-scheduled user equipments;
• obtain channel estimates for the demodulation reference signal port;
• equalize the one or more resource elements having zero power on the frequency domain resource allocation for the demodulation reference signal port;
• construct a custom constellation grid for a possible modulation order for the co-scheduled user equipment;
• slice the one or more equalized resource elements based on the custom constellation grid;
• and
• determine a modulation order for the co-scheduled user equipment based on a comparison of one or more predetermined modulation order fingerprints with the one or more sliced and equalized resource elements.

A method comprising:

• receiving, from a network node, a configuration for one or more resource elements having zero power;
• receiving downlink control information, wherein the downlink control information comprises an aperiodic indication for triggering resource elements having zero power;
• determining a number of co-scheduled user equipments in a physical downlink shared channel based on the following:
• an index associated with the one or more resource elements, a number of the one or more resource elements, and a number of the one or more resource elements triggered with the aperiodic indication;
• determining that the number of co-scheduled user equipments comprises two co-scheduled user equipments;
• for each of the two co-scheduled user equipments:
• detecting at least one frequency domain resource allocation for the co-scheduled user equipment;
• detecting at least one demodulation reference signal port for the co-scheduled user equipment;
• determining a frequency domain resource allocation for the co-scheduled user equipment based on the at least one detected frequency domain resource allocation and the number of co-scheduled user equipments;
• determining a demodulation reference signal port for the co-scheduled user equipment based on the at least one detected demodulation reference signal port and the number of co-scheduled user equipments;
• obtaining channel estimates for the demodulation reference signal port;
• equalizing the one or more resource elements having zero power on the frequency domain resource allocation for the demodulation reference signal port;
• constructing a custom constellation grid for a possible modulation order for the co-scheduled user equipment;
• slicing the one or more equalized resource elements based on the custom constellation grid;
• and
• determining a modulation order for the co-scheduled user equipment based on a comparison of one or more predetermined modulation order fingerprints with the one or more sliced and equalized resource elements.