Intra-slot PUCCH Repetition for Multi-TRP Reliability

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Solution Overview

Problem

Current PUCCH reliability for PUCCH formats 1, 3, and 4 can be improved with inter-slot repetition over multiple TRPs, but this introduces extra delays, and there is a need to balance reliability and latency, especially for Ultra-Reliable Low Latency (URLLC) applications, as well as determining the number of repetitions for mixed eMBB and URLLC traffic.

Innovation Solution

Intra-slot PUCCH repetition is performed multiple times within a slot, each toward a different TRP, with a different repetition associated with a TRP, and the number of repetitions is adjusted based on the associated PDSCH and traffic type, using spatial relations or unified TCI states to optimize reliability and latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If inter-slot repetition over multiple TRPs is used to improve PUCCH reliability, then reliability is improved, but latency increases

Engineering Contradiction:
ImprovePUCCH reliabilityVSAvoidlatency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The PUCCH transmission is segmented into multiple repetitions within a single slot, each directed toward a different TRP. This segmentation allows the transmission to be distributed across multiple spatial paths simultaneously, achieving diversity gain for reliability while maintaining low latency by completing all repetitions within the same slot boundary.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from inter-slot repetition (time dimension) to intra-slot repetition toward multiple TRPs (spatial dimension). By adding the spatial dimension through multiple TRPs within the same slot, the system achieves both reliability improvement and latency reduction, as all repetitions occur within the same slot rather than spanning multiple slots.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the number of PUCCH repetitions is increased to improve reliability, then reliability is improved, but resource consumption and battery usage increase

Engineering Contradiction:
ImprovePUCCH reliabilityVSAvoidbattery efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adapts the number of PUCCH repetitions based on traffic type requirements. For URLLC traffic, more repetitions are configured to ensure high reliability, while for eMBB traffic, fewer repetitions are used to conserve battery and reduce resource consumption. This dynamic adaptation allows the system to optimize the trade-off between reliability and energy usage according to actual service needs.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4193542B1System and methods of pucch enhancement with intra-slot repetitions towards multiple trps
Publication Date: 2024.04.17 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP4193542B1 patent drawingFigure 1~2
  • EP4193542B1 patent drawingFigure 3
  • EP4193542B1 patent drawingFigure 4

AI summary

Systems and methods are disclosed for Physical Uplink Control Channel enhancement. In one embodiment, a method performed by a user equipment in the wireless communication network that includes multiple Transmission and Receiving Points (TRPs), each associated with a spatial relation or a Transmission Configuration Indication (TCI) state, includes receiving, from a base station, a configuration of a first and second spatial relations or a configuration of a first and second TCI states for an uplink channel resource, and an indication of N transmission repetitions of the uplink channel. Also, the method includes transmitting the uplink channel in N consecutive sub-slots, and applying the first spatial relation or the first TCI state to the uplink channel transmission repetitions in a first subset of the sub-slots and applying the second spatial relation or the second TCI state to the uplink channel transmission repetitions in a second subset of the sub-slots.