Multi-TRP CSI Feedback Repetition for FR2 Blocking Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In New Radio (NR) systems, there is no support for repetition of Semi-Persistent CSI (SP-CSI) and periodic CSI reporting, leading to reliability issues, particularly in frequency range 2 (FR2) due to channel blocking, and CSI feedback is only sent to a single Transmission/Reception Point (TRP).
Innovation Solution
Implement a method to repeat CSI feedback over multiple TRPs by configuring multiple spatial relations or uplink TCI states for SP-CSI on PUSCH, SP-CSI on PUCCH, and periodic CSI on PUCCH, ensuring transmission occurs over different TRPs to enhance reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CSI feedback is sent to a single TRP, then the system complexity is low, but the reliability is poor due to channel blocking in FR2
Solution Approach 1:
The patent segments the CSI feedback transmission by directing it to multiple different TRPs (Transmission Reception Points) instead of a single TRP. This segmentation allows the feedback to reach at least one TRP even if another is blocked, thereby improving reliability without requiring complex redundancy mechanisms at the transmitter side.
Solution Approach 2:
The patent introduces spatial diversity by transmitting CSI feedback to multiple TRPs located at different spatial positions. This dimensional approach (adding spatial distribution) allows the system to overcome line-of-sight blocking issues in FR2 by providing alternative transmission paths through different spatial locations.
2Reliability
If multiple spatial relations are configured for SP-CSI on PUSCH, then the reliability improves by transmitting over multiple TRPs, but the device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring multiple spatial relations (SRBs) and associating them with different TRPs before actual CSI transmission occurs. This pre-configuration allows the UE to quickly switch between different spatial paths when needed, improving reliability without requiring complex real-time decision-making mechanisms.
Solution Approach 2:
The patent introduces dynamics by enabling the UE to dynamically select and switch between different spatial relations based on transmission conditions and TRP availability. This dynamic switching capability allows the system to adapt to changing channel conditions and maintain reliable communication without permanent complex configurations.
3Reliability
If CSI feedback is repeated over multiple TRPs, then the reliability in FR2 scenarios improves, but the loss of time for configuration and transmission increases
Solution Approach 1:
The patent reduces configuration time by performing preliminary actions - pre-configuring multiple spatial relations and TRP associations during initial system setup or connection establishment. This pre-configuration eliminates the need for time-consuming configuration processes during actual CSI transmission, thus reducing time loss while maintaining the ability to transmit to multiple TRPs for improved reliability.
Data Source
AI summary
Systems and methods for reliable Channel State Information (CSI) feedback towards multiple Transmission/Reception Points (TRPs) are provided. In some embodiments, a wireless device receives a configuration for one or more of: Semi-Persistent CSI (SP-CSI) reporting on PUCCH comprising a first PUCCH resource; SP-CSI reporting on PUSCH comprising a reporting periodicity and slot offset; and periodic CSI reporting on PUCCH comprising a second PUCCH resource activated with a third and a fourth spatial relations or uplink TCI states, and a reporting periodicity and slot offset. The wireless device also receives an appropriate activation command and transmits SP-CSI in a PUCCH resource; a periodic CSI in a PUCCH resource; and/or a SP-CSI in a PUSCH resource. In this way, reliability of SP-CSI on PUSCH, or SP-CSI on PUCCH, or periodic CSI on PUCCH can be improved by repeating the SP-CSI or periodic CSI over multiple TRPs.