User Equipment CSI Grouping for Subband Full-Duplex Interference
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Solution Overview
Problem
In subband full duplex (SBFD) systems, the increased coverage and reduced latency of uplink channels lead to interference with downlink channels, degrading the performance of user equipment (UE) and base stations.
Innovation Solution
The UE estimates channel state information for grouped subbands based on interference in downlink channels, generating subband groups and reporting CSI to the base station, allowing for differentiated precoder designs to mitigate interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If uplink channels use the same time domain resources as downlink channels in SBFD system, then coverage and capacity of uplink channels increase, but interference to downlink channels occurs
Solution Approach 1:
The patent divides the frequency spectrum into multiple subbands and groups them into subband groups. By estimating channel states separately for each subband group rather than treating the entire bandwidth uniformly, the system can identify and isolate interference-affected subbands from clean subbands, enabling targeted interference mitigation while maintaining overall uplink coverage
Solution Approach 2:
The patent applies different channel estimation and reporting strategies to different subband groups based on their local interference characteristics. Subbands experiencing uplink interference receive different handling than subbands without interference, allowing the system to optimize performance locally in each subband group while maintaining global system operation
2Productivity
If traditional channel estimation method is used in SBFD system, then downlink channel capacity is maintained, but performance degrades due to uplink interference
Solution Approach 1:
The patent implements dynamic channel estimation that adapts to varying interference conditions. The system continuously monitors interference in different subband groups and adjusts channel estimation parameters accordingly, allowing the downlink capacity to be maintained in non-interfered subbands while mitigating performance degradation in interfered subbands
Solution Approach 2:
The patent utilizes CSI feedback from the UE to the base station to identify interference patterns in different subband groups. This feedback mechanism enables the base station to adjust downlink transmission strategies based on real-time interference conditions, maintaining reliability while preserving downlink capacity where possible
3Measurement precision
If CSI is reported for each individual subband, then channel estimation accuracy is maximized, but overhead increases
Solution Approach 1:
The patent merges adjacent subbands into subband groups for channel estimation and reporting purposes. By combining multiple subbands into groups and reporting CSI at the group level rather than individual subband level, the system reduces reporting overhead while maintaining sufficient channel estimation accuracy through the grouped approach
Data Source
AI summary
An operating method of a user equipment (UE) in a subband full duplex (SBFD) system, the method including receiving a channel state information-reference signal (CSI-RS) from a base station (BS), generating a plurality of subband groups by grouping, based on interference to downlink channels, a plurality of subbands included in the downlink channels, based on interference to the downlink channels, and generating CSI of the plurality of subband groups, based on the CSI-RS.