HARQ Feedback Reliability via Dynamic PUCCH Resource Switching
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Solution Overview
Problem
Current wireless communication technologies face challenges in maintaining ultra-reliable and low-latency performance, particularly in scenarios like augmented reality, factory automation, and electrical power distribution, due to issues such as HARQ-ACK dropping caused by collisions with downlink symbols, which affect the efficiency of Hybrid Automatic Repeat Request (HARQ) feedback in New Radio (NR) systems.
Innovation Solution
The implementation of alternative or substitute PUCCH resources, grouping of DL SPS PDSCH occasions for HARQ feedback compression, enhanced UCI resource elements mapping for repeated PUCCH piggybacked on PUSCH, and dynamic PUCCH resource determination for carrier aggregation, along with dynamic PUCCH carrier switching and HARQ identifier determination for multi-transport block transmissions in unlicensed spectrum, to mitigate these challenges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ feedback is transmitted using traditional PUCCH resources, then the feedback mechanism is simple, but HARQ-ACK feedback is dropped due to collisions with downlink symbols
Solution Approach 1:
The patent implements dynamic PUCCH resource determination where the network dynamically selects alternative PUCCH resources based on collision detection. The UE receives indication information about alternative PUCCH resources and uses them when collisions with downlink symbols are detected, making the system adaptive and dynamic rather than static
Solution Approach 2:
The patent introduces alternative PUCCH resources as intermediary resources that mediate between the primary PUCCH resources and the downlink symbols. When collision occurs, the system switches to these intermediary resources to transmit HARQ-ACK feedback, avoiding direct conflict with downlink transmissions
2Productivity
If multiple DL SPS PDSCH occasions are handled separately, then each occasion is processed independently, but HARQ feedback overhead increases
Solution Approach 1:
The patent merges multiple DL SPS PDSCH occasions into a single HARQ feedback transmission. Instead of transmitting separate feedback for each PDSCH occasion, the system combines them and transmits a single consolidated feedback signal, reducing overhead while maintaining processing independence
Solution Approach 2:
The patent makes the HARQ feedback mechanism universal by enabling it to handle multiple PDSCH occasions simultaneously. The same feedback mechanism serves multiple purposes (acknowledging multiple PDSCH transmissions) without requiring separate dedicated feedback paths for each occasion
3Speed
If PUCCH resources are fixed, then resource allocation is simple, but latency increases due to inability to adapt to collisions
Solution Approach 1:
The patent implements dynamic PUCCH resource determination where the network dynamically selects alternative PUCCH resources based on collision detection. The UE receives indication information about alternative PUCCH resources and uses them when collisions with downlink symbols are detected, making the system adaptive and dynamic rather than static
Solution Approach 2:
The patent prepares alternative PUCCH resources in advance by providing indication information from the network. This preliminary preparation allows the UE to quickly switch to alternative resources when collisions occur, reducing latency without requiring complex real-time resource allocation algorithms
Data Source
AI summary
Various embodiments herein relate to techniques for ultra-reliable and low latency communication (URLLC) in wireless cellular networks. For example, embodiments include hybrid automatic repeat request (HARQ) enhancements for URLLC. Additionally, embodiments include techniques for determining a HARQ identifier (ID) for multi-transport block (TB) transmissions, such as multi-TB configured grant transmissions and/or multi-TB transmissions in unlicensed spectrum.