PUSCH Multi-TRP Scheduling Using UL TCI State Indication
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Solution Overview
Problem
Existing NR systems lack efficient mechanisms for PUSCH transmission to multiple Transmission/Reception Points (TRPs), particularly in scenarios requiring high reliability like URLLC, due to limited flexibility in beam management and resource allocation.
Innovation Solution
Implementing UL TCI states for PUSCH scheduling, allowing multiple TRPs to be targeted by indicating different TCI states in UL DCI, enabling flexible spatial relations for PUSCH transmission and redundancy version application across TRPs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional single-TRP PUSCH scheduling is used, then system complexity is low, but transmission reliability is insufficient for high-reliability scenarios like URLLC
Solution Approach 1:
The patent segments the PUSCH transmission by dividing it into multiple repetitions, where each repetition can be independently scheduled and transmitted to different TRPs. This segmentation allows the system to achieve diversity gain across multiple transmission paths while maintaining manageable complexity through independent handling of each segment.
Solution Approach 2:
The patent introduces a new dimension to PUSCH scheduling by enabling multi-TRP transmission. Instead of relying on a single transmission path, the system extends the transmission dimension to include multiple spatial paths (different TRPs), thereby improving reliability without proportionally increasing system complexity.
2Area of stationary object
If multiple TCI states are indicated for multi-TRP transmission, then transmission coverage is improved, but DCI overhead increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring TCI states through higher-layer signaling before actual PUSCH transmission. This allows the DCI to reference pre-established TCI configurations rather than transmitting complete TCI state information, thereby reducing DCI overhead while maintaining the ability to indicate multiple TRPs for enhanced coverage.
3Reliability
If PUSCH repetitions are scheduled across multiple slots, then transmission reliability is enhanced, but transmission latency increases
Solution Approach 1:
The patent applies dynamics by making the PUSCH repetition structure flexible and adaptable. The system can dynamically adjust the number of repetitions, their timing, and target TRPs based on channel conditions and reliability requirements. This dynamic approach allows the system to achieve necessary reliability while minimizing latency by adapting to real-time conditions rather than using fixed, conservative repetition schemes.
Data Source
AI summary
Systems and methods to support Physical Uplink Shared Channel (PUSCH) multi-Transmission/Reception Point (TRP) scheduling are provided. In some embodiments, the wireless device performs one or more of: obtaining a configuration for Transmission Configuration Indicator (TCI) states for Uplink (UL) PUSCH scheduling; activating/deactivating a subset of configured TCI states). If two TCI states are indicated, the wireless device transmits two different PUSCHs each corresponding to one of the indicated TCI states. If one TCI state is indicated, the wireless device transmits a single PUSCH corresponding to the indicated TCI state. The wireless device maps indicated TCI states to the transmission occasions or actual repetitions is preconfigured via higher layer parameter(s) or is given by a predefined rule. The wireless device applies a Transmitted Precoding Matrix Indicator (TPMI) to transmission occasions or actual repetitions associated with each indicated TCI state based on a signaled value and/or a predefined value.