5G • 5G-Advanced (Rel-18)
Sub-Band CSI Reporting
High-Resolution Sub-Band Channel State Information Reporting
Provides fine-grained frequency-selective channel state reporting per resource block group, maximizing multi-user MIMO scheduling accuracy.
Technical Explanation
In wideband 5G channels, multi-path frequency selectivity causes channel characteristics to vary significantly across an 80 MHz carrier. Rel-18 sub-band CSI reporting provides flexible granularity, allowing UEs to report precise precoding matrix indicators (PMI) and CQI for localized resource blocks, enabling schedulers to achieve high multi-user spatial isolation.
Key Functions
- Reports fine-grained PMI and CQI values per localized physical resource block group
- Overcomes frequency-selective multipath fading across wideband 5G carriers
- Maximizes multi-user MIMO spatial multiplexing gains by minimizing inter-user leakage
- Supports adaptive reporting granularity balancing feedback overhead against accuracy
Specifications
3GPP TS 38.214 (Rel-18)
Interfaces
Uu (PUCCH/PUSCH)
Related 5G Concepts
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