Article directory
foreword
This article is the parent of [5G NR] UE reporting CSI process—CSI framework—CSI resource configuration and [5G NR] UE reporting CSI process—CSI framework—CSI report configuration. It mainly introduces and summarizes the general framework of UE reporting CSI process .
1. Overview of the CSI Framework
The process of UE reporting CSI is generally divided into two steps or stages [1] :
- First, the gNB sends the CSI-RS and/or SSB to the UE according to the CSI resource configuration .
- Secondly, the UE measures the CSI-RS and/or DM-RS (located on the PBCH of the SSB), and reports CSI to the gNB according to the CSI report configuration .
After receiving the CSI reported by the UE, the gNB can perform operations such as beam management and channel-dependent scheduling based on it.
In summary, the CSI Framework (CSI Framework) mainly includes two parts : CSI Resource Setting/Configuration and CSI Report Setting/Configuration. The CSI resource configuration mainly specifies the structure of the CSI-RS, the bandwidth occupied in the frequency domain, and the behavior in the time domain (including periodic, semi-persistent, and aperiodic). The CSI report configuration mainly specifies the CSI resource configuration associated with the CSI report, the configuration of the CSI report in the frequency domain (including the CSI report frequency band and whether the PMI/CQI report is broadband or sub-band), and the behavior of the CSI report in the time domain ( Including periodic, semi-persistent, aperiodic) and CSI-related indicators reported by UE (including CQI, PMI, CRI, SSBRI, LI, RI, L1-RSRP, L1-SINR) [1] [ 2 ] .
According to the different CSI-RS and its usage, the CSI framework, that is, the framework of CSI resource configuration and CSI report configuration, is also different, which is mainly reflected in the difference of IE at the RRC layer [3 ] :
- For the non-zero power CSI-RS ( Non -Zero Power CSI-RS, NZP CSI-RS ) and CSI-IM (Channel State Information-Interference Measurement), which are configured in CSI-MeasConfig IE under ServingCellConfig IE .
- For NZP CSI-RS used for mobility management (Mobility), it is configured in CSI-RS-ResourceConfigMobility IE.
- For zero-power CSI-RS (Zero-Power CSI-RS, ZP CSI-RS ), it is configured in the PDSCH-Config IE.
Below we focus on the general CSI configuration framework, that is, the configuration of CSI-MeasConfig IE. Regarding the configuration of NZP CSI-RS for mobility management and ZP CSI-RS for PDSCH rate matching, we will introduce it in [5G NR] UE reporting CSI process—CSI framework—CSI resource configuration .
2. CSI-MeasConfig IE configuration framework
2.1 Overview of CSI-MeasConfig IE
The CSI-MeasConfig IE is used to configure CSI-RS resources (more precisely, NZP CSI-RS and CSI-IM except for mobility management) and CSI reporting [4] .
Each CSI-MeasConfig IE contains 1 or more NZP CSI-RS resources ( NZP-CSI-RS-Resource ) and resource sets ( NZP-CSI-RS-ResourceSet ), and/or 1 or more CSI-IMs resource ( CSI-IM-Resource ) and resource set ( CSI-IM-ResourceSet ), and/or 1 or more SSB resource sets ( CSI-SSB-ResourceSet ), 1 or more CSI report configurations ( CSI-ReportConfig ), 1 or more CSI resource configurations ( CSI-ResourceConfig ), 1 or 2 trigger state lists (ie CSI-AperiodicTriggerStateList and CSI-SemiPersistentOnPUSCH-TriggerStateList ). Figure 2-1 below shows the CSI-MeasConfig IE.
About NZP-CSI-RS-Resource , NZP-CSI-RS-ResourceSet , CSI-IM-Resource , CSI-IM-ResourceSet , CSI-SSB-ResourceSet , CSI-ReportConfig , CSI-ResourceConfig , please refer to 【5G NR】 The process of UE reporting CSI - CSI framework - CSI resource configuration and [5G NR] UE reporting process of CSI - CSI framework - CSI report configuration . Below, we mainly introduce the two high-level parameters of CSI-AperiodicTriggerStateList and CSI-SemiPersistentOnPUSCH-TriggerStateList .
2.2 CSI-AperiodicTriggerStateList IE
The CSI-AperiodicTriggerStateList IE is used to configure one or more aperiodic CSI reporting trigger states for the UE, that is, CSI-AperiodicTriggerState . Each CSI-AperiodicTriggerState contains 1 or more CSI-ReportConfig associated with it , and associated NZP CSI-RS and/or CSI-IM and/or SSB resource sets for channel measurement and/or interference measurement . Figure 2-2 below shows the CSI-AperiodicTriggerStateList IE.
As shown in Figure 2-2 above, each CSI-AperiodicTriggerStateList consists of at most 128 CSI-AperiodicTriggerStates ( maxNrOfCSI-AperiodicTrigger is 128), and each CSI-AperiodicTriggerState contains at most 16 CSI-AssociatedReportConfigInfo ( maxNrofReportConfigPerAperiodicTrigger is 166) Each CSI-AssociatedReportConfigInfo must contain 1 reportConfigId , corresponding to 1 CSI-ReportConfigId , through which the CSI-ReportConfigId is associated with the corresponding CSI-ReportConfig . Each CSI-AssociatedReportConfigInfo must also contain 1 resourcesForChannel , where each resourcesForChannel contains 1 nzp-CSI-RS or 1csi-SSB-ResourceSet . resourceSet in nzp-CSI-RS indicates the NZP CSI-RS resource set for channel measurement ( NZP-CSI-RS-ResourceSet ), while csi-SSB-ResourceSet indicates the SSB resource set for channel measurement ( CSI-SSB- ResourceSet ). In addition to resourcesForChannel , each CSI-AssociatedReportConfigInfo can also contain 1 csi-IM-ResourcesForInterference and/or 1 nzp-CSI-RS-ResourcesForInterference (both Optional), the former indicates the CSI-IM resource used for interference measurement set ( CSI-IM-ResourceSet ), while the latter indicates the NZP CSI-RS resource set ( NZP-CSI-RS-ResourceSet ) used for interference measurement.
Specifically, in CSI-AssociatedReportConfigInfo , the meanings of each parameter field are as follows [4] :
- reportConfigId : The ID of the CSI-ReportConfig , corresponding to the reportConfigId of a CSI-ReportConfig configured in the high-level parameter csi-ReportConfigToAddModList in the CSI -MeasConfig IE .
- resourcesForChannel：
- nzp-CSI-RS：
- resourceSet : NZP CSI-RS resource set for channel measurement, corresponding to the NZP CSI -RS resource set in nzp-CSI-RS-ResourceSetList in CSI-ResourceConfig , where CSI-ResourceConfig corresponds to the CSI-ReportConfig indicated by reportConfigId The CSI resource configuration indicated by the high-level parameter resourcesForChannelMeasurement . 1 means the first NZP CSI-RS resource set in nzp-CSI-RS-ResourceSetList , 2 means the second NZP CSI-RS resource set in nzp-CSI-RS-ResourceSetList , and so on.
- qcl-info : TCI-States reference list, which provides QCL source and QCL type for the NZP CSI-RS resources in the NZP CSI-RS resource set indicated by resourceSet .
- csi-SSB-ResourceSet : The SSB resource set used for channel measurement, corresponding to the SSB resource set in csi-SSB-ResourceSetList in CSI-ResourceConfig , where CSI-ResourceConfig corresponds to the high-level parameter resourcesForChannelMeasurement in CSI-ReportConfig indicated by reportConfigId The indicated CSI resource configuration. 1 means the first SSB resource set in csi-SSB-ResourceSetList , 2 means the second SSB resource set in csi-SSB-ResourceSetList , and so on.
- nzp-CSI-RS：
- csi-IM-ResourcesForInterference : CSI -IM resource set used for interference measurement, corresponding to the CSI-IM resource set in csi-IM-ResourceSetList in CSI-ResourceConfig , where CSI-ResourceConfig corresponds to the CSI-ReportConfig indicated by reportConfigId The CSI resource configuration indicated by the high-layer parameter csi-IM-ResourcesForInterference . 1 indicates the first CSI-IM resource set in the csi-IM-ResourceSetList , 2 indicates the second CSI-IM resource set in the csi-IM-ResourceSetList , and so on.
- nzp-CSI-RS-ResourcesForInterference : NZP CSI-RS resource set for interference measurement, corresponding to the NZP CSI-RS resource set in nzp-CSI-RS-ResourceSetList in CSI-ResourceConfig , where CSI-ResourceConfig corresponds to reportConfigId The CSI resource configuration indicated by the high layer parameter nzp-CSI-RS-ResourcesForInterference in the indicated CSI-ReportConfig . 1 means the first NZP CSI-RS resource set in nzp-CSI-RS-ResourceSetList , 2 means the second NZP CSI-RS resource set in nzp-CSI-RS-ResourceSetList , and so on.
2.3 CSI-SemiPersistentOnPUSCH-TriggerStateList IE
The CSI-SemiPersistentOnPUSCH-TriggerStateList IE is used to configure one or more PUSCH-based semi-persistent CSI reporting trigger states for the UE, that is, CSI-SemiPersistentOnPUSCH-TriggerState . Each CSI-SemiPersistentOnPUSCH-TriggerState contains only 1 CSI-ReportConfig associated with it . Figure 2-3 below shows the CSI-SemiPersistentOnPUSCH-TriggerState IE.
As shown in Figure 2-3 above, each CSI-SemiPersistentOnPUSCH-TriggerStateList consists of at most 64 CSI-SemiPersistentOnPUSCH-TriggerStates ( maxNrOfSemiPersistentPUSCH-Triggers is 64), and each CSI-SemiPersistentOnPUSCH-TriggerState only contains 1 associatedReportConfigInfo , corresponding to 1 A CSI-ReportConfigId , through which the CSI-ReportConfigId is associated with the corresponding CSI-ReportConfig .
Figure 2-4 below summarizes the general configuration framework of the entire CSI-MeasConfig IE.
