Flexible CSI-RS to SRS Mapping for Uplink MIMO Multi-Beam
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Solution Overview
Problem
Current wireless communication technologies, such as LTE and NR, lack support for multiple beams in uplink MIMO due to rigid CSI-RS and SRS association, which limits performance in scenarios like partial channel reciprocity, asymmetric interference, and carrier aggregation.
Innovation Solution
Implement flexible CSI-RS and SRS association methods that allow for multiple beams on the uplink by configuring SRSs based on reception settings and transmission settings, enabling 1:1, X:1, and 1:X mapping configurations with CSI-RSs, and controlling transmission settings within a correlation threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If rigid CSI-RS and SRS association is used, then system simplicity is maintained, but uplink MIMO performance is limited
Solution Approach 1:
The patent implements dynamic association between CSI-RS and SRS resources, allowing the system to adaptively configure mapping relationships (1:1, X:1, or 1:X) based on channel conditions and interference characteristics. This dynamic configuration enables the system to optimize uplink MIMO performance while maintaining manageable complexity through standardized procedures.
2Device complexity
If single beam configuration is used, then configuration complexity is reduced, but performance in partial channel reciprocity scenarios is degraded
Solution Approach 1:
The patent segments the uplink transmission into multiple beams, each associated with specific CSI-RS resources. By configuring multiple SRS resources with different spatial filters and associating them with different CSI-RS resources, the system can handle partial channel reciprocity scenarios where different beams experience different channel conditions, thereby improving overall performance.
Solution Approach 2:
The patent applies local quality by allowing different beams to have different transmission settings and spatial characteristics. Each SRS resource can be configured with specific spatial filters, power control parameters, and association rules tailored to local channel conditions, enabling optimized performance for each beam while managing complexity through modular configuration.
3Adaptability or versatility
If flexible mapping configurations (1:1, X:1, 1:X) are implemented, then adaptability to different scenarios is improved, but system complexity increases
Solution Approach 1:
The patent implements dynamic mapping configurations where the association between CSI-RS and SRS resources can be flexibly set to 1:1, X:1, or 1:X relationships. This dynamic adaptability allows the system to optimize for different scenarios (full reciprocity, partial reciprocity, asymmetric interference) while maintaining standardized configuration procedures that prevent excessive complexity.
Data Source
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AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may determine a set of sounding reference signals (SRSs) based at least in part on a mapping configuration, the mapping configuration being associated with mapping the set of SRSs to a set of channel state information reference signals (CSI-RSs) received by the UE, and the set of CSI-RSs being received based at least in part on a set of reception settings, each associated with a respective CSI-RS of the set of CSI-RSs; determine, based at least in part on the set of reception settings, a set of transmission settings, each corresponding to a respective SRS of the set of SRSs; and transmit the set of SRSs based at least in part on the set of transmission settings. Numerous other aspects are provided.