Channel state information reference signal configuration for high velocity
A method of providing channel state information (CSI) reference signal (RS) configuration is proposed to support high velocity in new radio (NR) systems. A CSI-RS resource can be configured with a bursty period in which the same CSI-RS resource is repeatedly transmitted over time. Any two repetitions of the CSI-RS resource are not overlapped in time. For periodic and semi-persistent CSI-RS, the repetitions of CSI-RS in the bursty period can be signalled by radio resource control (RRC) signaling. For aperiodic CSI-RS, the CSI-RS repetitions in the bursty period can be indicated by the triggering downlink control information (DCI). UE can acquire Doppler-domain information based on the CSI-RS repetition to facilitate high velocity scenarios in 5G NR systems.
1 . A method comprising:
receiving, by a user equipment (UE), channel state information reference signals (CSI-RS) configuration information for periodic or semi-persistent CSI-RS transmission from a base station (BS);
determining a CSI-RS resource with a CSI-RS periodicity, wherein a CSI-RS is repeatedly transmitted during a bursty period within each CSI-RS period, wherein the bursty period is shorter than its corresponding CSI-RS period;
measuring a number of CSI-RS repetitions of a downlink channel that is received during the bursty period; and
estimating a CSI of the downlink channel based on the measurements on the number of CSI-RS repetitions.
2 . The method of claim 1 , wherein the CSI-RS repetition is signalled by a slot index s, a slot gap d and a number N, wherein the CSI-RS resource is repeated every d slots totally N times, starting from slot s.
3 . The method of claim 1 , wherein the CSI-RS repetition is signalled by a symbol index s, a symbol gap d and a number N, wherein the CSI-RS resource is repeated every d symbols totally N times, starting from symbol s within the first slot of the bursty period.
4 . The method of claim 1 , wherein the CSI-RS repetition in the bursty period is signalled by a number of slots and a symbol position within each slot.
5 . The method of claim 1 , wherein each configured bursty period has the same number of CSI-RS repetitions for CSI-RS resources in the same CSI-RS resource set.
6 . The method of claim 1 , wherein the number of CSI-RS repetitions is updated by MAC-CE for semi-persistent CSI-RS transmission.
7 . The method of claim 1 , wherein the UE is configured with a higher layer parameter for CSI reporting, wherein a required number of processing units O CPU =KN, where K is the number of CSI-RS resources, and N is the number of CSI-RS repetitions.
8 . A User Equipment (UE) comprising:
a receiver that receives channel state information reference signals (CSI-RS) configuration information for periodic or semi-persistent CSI-RS transmission from a base station (BS);
a control circuit that determines a CSI-RS resource with a CSI-RS periodicity, wherein a CSI-RS is repeatedly transmitted during a bursty period within each CSI-RS period, wherein the bursty period is shorter than its corresponding CSI-RS period;
a measurement circuit that measures a CSI-RS repetition of a downlink channel that is received during the bursty period; and
a CSI computation circuit that estimates a CSI of the downlink channel based on the measurements on the CSI-RS repetition.
9 . The UE of claim 8 , wherein the CSI-RS repetition is signalled by a slot index s, a slot gap d and a number N, wherein the CSI-RS resource is repeated every d slots totally N times, starting from slot s.
10 . The UE of claim 8 , wherein the CSI-RS repetition is signalled by a symbol index s, a symbol gap d and a number N, wherein the CSI-RS resource is repeated every d symbols totally N times, starting from symbol s within the first slot of the bursty period.
11 . The UE of claim 8 , wherein the CSI-RS repetition in the bursty period is signalled by a number of slots and a symbol position within each slot.
12 . The UE of claim 8 , wherein each configured bursty period has the same number of CSI-RS repetitions for CSI-RS resources in the same CSI-RS resource set.
13 . The UE of claim 8 , wherein the number of CSI-RS repetitions is updated by MAC-CE for semi-persistent CSI-RS transmission.
14 . The UE of claim 8 , wherein the UE is configured with a higher layer parameter for CSI reporting, wherein a required number of processing units O CPU =KM, where K is the number of CSI-RS resources, and N is the number of CSI-RS repetitions.
15 . A method comprising:
receiving, by a user equipment (UE), channel state information reference signals (CSI-RS) configuration information for aperiodic CSI-RS transmission from a base station (BS);
determining a triggering condition for an aperiodic CSI-RS transmission, wherein a CSI-RS is repeatedly transmitted during a bursty period, wherein the bursty period is shorter than its corresponding CSI-RS period;
measuring a number of CSI-RS repetitions of a downlink channel that is received during the bursty period; and
estimating a CSI of the downlink channel based on the measurements on the number of CSI-RS repetitions.
16 . The method of claim 15 , wherein the UE receives a downlink control information (DCI) for triggering the aperiodic CSI-RS transmission.
17 . The method of claim 16 , wherein the number of CSI-RS repetitions is indicated by the triggering DCI.
18 . The method of claim 16 , wherein the triggering DCI occurs in slot n, and the number of CSI-RS repetitions starts from slot n+X, wherein X is the CSI-RS triggering offset.
19 . The method of claim 18 , wherein the CSI-RS triggering offset X is configured by a radio resource control (RRC) signaling.
20 . The method of claim 15 , wherein the UE is configured with a higher layer parameter for CSI reporting, wherein a required number of processing units O CPU =KN, where K is the number of CSI-RS resources, and N is the number of CSI-RS repetitions.