Time density and frequency density determination of phase tracking reference signals (PT-RS) in new radio (NR) systems

1. An apparatus of a User Equipment (UE), the apparatus comprising:

memory; and processing circuitry, configured to:

when transform precoding is not enabled, and if the UE is configured with a higher layer parameter phaseTrackingRS in a DMRS-UplinkConfig information element (IE):

decode, from a Next Generation Node-B (gNB), control signaling that includes a PTRS-UplinkConfig IE;

determine a time density of phase tracking reference signal (PT-RS) to be transmitted by the UE, the time density of the PT-RS determined based at least partly on a comparison between a scheduled modulation and coding scheme (MCS) and a plurality of MCS thresholds;

determine a frequency density of the PT-RS based at least partly on a comparison between a scheduled bandwidth and a plurality of resource block (RB) thresholds,

wherein a higher layer parameter timeDensity in the PTRS-UplinkConfig IE indicates the plurality of MCS thresholds,

wherein a higher layer parameter frequencyDensity in the PTRS-UplinkConfig IE indicates the plurality of RB thresholds; and

encode the PT-RS, in accordance with the time density of the PT-RS and the frequency density of the PT-RS, for a transmission of an uplink control information (UCI) report on a physical uplink shared channel (PUSCH) without uplink shared channel (UL-SCH) data.

2. The apparatus according to claim 1 , the processing circuitry further configured to:

decode downlink control information (DCI) that includes an uplink grant carrying the scheduled MCS for the transmission of the UCI report,

wherein the UCI report includes hybrid automatic repeat request-acknowledgement (HARQ-ACK) and a CSI report,

wherein the CSI report includes a CSI part 1 transmission and is configurable to include a CSI part 2 transmission;

determine the time density of the PT-RS and the frequency density of the PT-RS based at least partly on the scheduled MCS; and

encode the HARQ-ACK, the CSI part 1 transmission and/or the CSI part 2 transmission for transmission on the PUSCH without UL-SCH data in accordance with allocated resources that exclude resources for the PT-RS.

3. The apparatus according to claim 1 , the processing circuitry further configured to:

decode downlink control information (DCI) that includes an uplink grant that indicates, for the transmission of the UCI report, the scheduled MCS,

wherein the UCI report includes a CSI report,

wherein the CSI report includes a CSI part 1 transmission and is configurable to include a CSI part 2 transmission,

wherein the scheduled MCS indicated in the DCI is for the CSI part 1 transmission and/or the CSI part 2 transmission;

determine a code rate and a modulation order based on the scheduled MCS indicated in the DCI; and

encode the CSI part 1 transmission and/or the CSI part 2 transmission for transmission on the PUSCH without UL-SCH data in accordance with the time density of the PT-RS and the frequency density of the PT-RS.

4. The apparatus according to claim 1 , the processing circuitry further configured to:

as part of the determination of the time density of the PT-RS, determine a time spacing parameter as:

4 symbols, if the scheduled MCS is greater than or equal to a first MCS threshold and is less than a second MCS threshold,

2 symbols, if the scheduled MCS is greater than or equal to the second MCS threshold and is less than a third MCS threshold, and

1 symbol, if the scheduled MCS is greater than or equal to the third MCS threshold and is less than a fourth MCS threshold; and

determine that the UE is to refrain from transmission of the PT-RS if the scheduled MCS is less than the first MCS threshold.

5. The apparatus according to claim 4 , the processing circuitry further configured to:

as part of the determination of the frequency density of the PT-RS, determine a frequency spacing parameter as:

2 RBs, if the scheduled bandwidth is greater than or equal to a zeroth RB threshold and is less than a first RB threshold, and

4 RBs, if the scheduled bandwidth is greater than or equal to the first RB threshold; and

determine that the UE is to refrain from transmission of the PT-RS if the scheduled bandwidth is less than the zeroth RB threshold.

6. The apparatus according to claim 5 , the processing circuitry further configured to:

if either or both of the higher layer parameters timeDensity and/or frequencyDensity in the PTRS-UplinkConfig IE are configured, determine a presence of antenna ports of the PT-RS and pattern as a function of the scheduled MCS and a scheduled bandwidth in a corresponding scheduled bandwidth, in accordance with:

the time spacing parameter,

the frequency spacing parameter,

that the UE is to refrain from transmission of the PT-RS if the scheduled MCS is less than the first MCS threshold, and

that the UE is to refrain from transmission of the PT-RS if the scheduled bandwidth is less than a zeroth MCS threshold.

7. The apparatus according to claim 5 , the processing circuitry further configured to:

encode the PT-RS for transmission in accordance with the time spacing parameter and further in accordance with the frequency spacing parameter,

wherein consecutive symbols that include the PT-RS are spaced by the number of symbols of the time spacing parameter,

wherein consecutive RBs that include the PT-RS are spaced by the number of RBs of the frequency spacing parameter; and

refrain from transmission of the PT-RS if it is determined that the UE is to refrain from transmission of the PT-RS.

8. The apparatus according to claim 5 , wherein:

the MCS thresholds are in a range of MCS-0 through MCS-28 or in a range of MCS-0 through MCS-29, and

the RB thresholds are in a range of one RB through 276 RBs.

9. The apparatus according to claim 1 , the processing circuitry further configured to:

decode, from the gNB, downlink control information (DCI) that indicates the scheduled MCS.

10. The apparatus according to claim 1 , the processing circuitry further configured to:

decode, from the gNB, control signaling that indicates the scheduled bandwidth.

11. The apparatus according to claim 1 , the processing circuitry further configured to:

decode downlink control information (DCI) that includes an uplink grant that indicates a code rate for the PUSCH without UL-SCH data and a modulation order for the PUSCH without UL-SCH data; and

determine the scheduled MCS based on the code rate and the modulation order.

12. The apparatus according to claim 1 , wherein the UE is arranged to operate in accordance with a new radio (NR) protocol.

13. The apparatus according to claim 1 , wherein:

the apparatus includes a transceiver to receive the control signaling,

the processing circuitry includes a baseband processor to determine the time density of the PT-RS and/or the frequency density of the PT-RS, and

the memory is configured to store information related to the time density of the PT-RS and/or the frequency density of the PT-RS.

14. A non-transitory computer-readable storage medium that stores instructions for execution by processing circuitry of a Next Generation Node-B (gNB), the instructions to configure the processing circuitry to:

encode a PTRS-UplinkConfig IE to include:

a higher layer parameter timeDensity that indicates a plurality of MCS thresholds, and

a higher layer parameter frequencyDensity that indicates a plurality of resource block (RB) thresholds;

encode, for transmission to a User Equipment (UE), control signaling that includes the PTRS-UplinkConfig IE;

encode, for transmission to the UE, downlink control information (DCI) that includes a scheduled modulation and coding scheme (MCS) and a scheduled bandwidth;

determine a time density of phase tracking reference signal (PT-RS) to be received from the UE, the time spacing density determined based at least partly on a comparison between the scheduled MCS and the plurality of MCS thresholds; and

determine a frequency density of the PT-RS, the frequency spacing parameter determined based at least partly on a comparison between the scheduled bandwidth and the plurality of RB thresholds.

15. The non-transitory computer-readable storage medium according to claim 14 , the instructions to further configure the processing circuitry to:

as part of the determination of the time density of the PT-RS, determine a time spacing parameter as:

4 symbols, if the scheduled MCS is greater than or equal to a first MCS threshold and is less than a second MCS threshold,

2 symbols, if the scheduled MCS is greater than or equal to the second MCS threshold and is less than a third MCS threshold, and

1 symbol, if the scheduled MCS is greater than or equal to the third MCS threshold and is less than a fourth MCS threshold;

determine that the UE is to refrain from transmission of the PT-RS if the scheduled MCS is less than the first MCS threshold;

as part of the determination of the frequency density of the PT-RS, determine a frequency spacing parameter as:

2 RBs, if the scheduled bandwidth is greater than or equal to a zeroth RB threshold and is less than a first RB threshold, and

4 RBs, if the scheduled bandwidth is greater than or equal to the first RB threshold; and

determine that the UE is to refrain from transmission of the PT-RS if the scheduled bandwidth is less than the zeroth RB threshold.

16. The non-transitory computer-readable storage medium according to claim 15 , the instructions to further configure the processing circuitry to:

decode the PT-RS, the PT-RS received from the UE in accordance with the time spacing parameter and further in accordance with the frequency spacing parameter,

wherein consecutive symbols that include the PT-RS are spaced by the number of symbols of the time spacing parameter,

wherein consecutive RBs that include the PT-RS are spaced by the number of RBs of the frequency spacing parameter.

17. An apparatus of a User Equipment (UE), the apparatus comprising:

memory; and processing circuitry, configured to:

decode, from a Next Generation Node-B (gNB), control signaling that includes a PDSCH-Config information element (IE) that configures the UE with a list of up to M Transmission Configuration Indication (TCI) states to decode a physical downlink shared channel (PDSCH) according to a detected physical downlink control channel (PDCCH) with downlink control information (DCI) intended for the UE and a given serving cell, wherein M depends on a capability of the UE,

wherein each TCI state includes one or more parameters for configuring a quasi-colocation relationship between one or two downlink reference signals and demodulation reference signal (DM-RS) ports of the PDSCH;

decode, from the gNB, downlink control information (DCI) that indicates a TCI state, from the list of up to M TCI states, to be used by the UE;

detect the PDCCH, wherein for DM-RS of the PDCCH, the TCI indicated in the DCI indicates a quasi co-location type that is one of: QCL-TypeA and QCL-TypeD; and

decode the PDSCH, wherein for DM-RS of the PDSCH, the TCI indicated in the DCI indicates a quasi co-location type that is one of: QCL-TypeA and QCL-TypeD.

18. The apparatus according to claim 17 , wherein:

for the DM-RS of the PDCCH, the TCI indicated in the DCI indicates a quasi co-location type that is:

QCL-TypeA with a channel state information reference signal (CSI-RS) resource in an NZP-CSI-RS-ResourceSet configured with higher layer parameter trs-Info and, when applicable, QCL-TypeD with the same CSI-RS resource, or

QCL-TypeA with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher layer parameter trs-Info and, when applicable, QCL-TypeD with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with a higher layer parameter repetition, or

QCL-TypeA with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured without the higher layer parameter trs-Info and without the higher layer parameter repetition, when QCL-TypeD is not applicable.

19. The apparatus according to claim 17 , wherein:

for the DM-RS of the PDSCH, the TCI indicated in the DCI indicates a quasi co-location type that is:

QCL-TypeA with a channel state information reference signal (CSI-RS) resource in an NZP-CSI-RS-ResourceSet configured with higher layer parameter trs-Info and, when applicable, QCL-TypeD with the same CSI-RS resource, or

QCL-TypeA with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher layer parameter trs-Info and, when applicable, QCL-TypeD with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with a higher layer parameter repetition, or

QCL-TypeA with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured without the higher layer parameter trs-Info and without the higher layer parameter repetition and, when applicable, QCL-TypeD with the same CSI-RS resource.

20. The apparatus according to claim 17 , wherein:

if either CSI-RS resource in an NZP-CSI-RS resource set or phase tracking reference signals (PT-RS) is not configured,

for the DM-RS of the PDSCH, the TCI indicated in the DCI does not indicate a quasi-co-location type in which the DM-RS is quasi co-located with a CSI-RS resource that is not quasi co-located with a synchronization signal block (SSB).