HARQ-ACK Codebook Partitioning for 5G Inter-Cell Mobility
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Solution Overview
Problem
In 5G New Radio (NR) systems, especially in Massive MIMO scenarios, the inter-cell handover process is hindered by beam-based communications, leading to increased delay and inefficiency due to the need for frequent CORESET configuration updates, which complicates HARQ-ACK codebook determination and Downlink Assignment Index interpretation across multiple cells.
Innovation Solution
A method and device for determining HARQ-ACK codebooks in multi-TRP environments under L1/2 mobility management, where information blocks with specific indices are used to indicate resource sets, and signaling fields are employed to determine the number of HARQ-ACK bits, allowing for simultaneous control signal reception from multiple cells and separate feedback of HARQ-ACKs based on quasi-colocated reference signal resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If beam-based communications are used in Massive MIMO scenarios, then communication quality is enhanced through narrow beamforming, but inter-cell handover delay increases and system efficiency decreases
Solution Approach 1:
The patent segments the HARQ-ACK codebook into multiple groups, each associated with a specific CORESETPoolIndex. This segmentation allows independent handling of feedback for different control resource sets, enabling faster handover by avoiding complete codebook reconfiguration while maintaining beamforming quality.
Solution Approach 2:
The patent introduces dynamic TCI-State activation and deactivation mechanisms that allow the system to adaptively switch between different beam configurations during handover. This dynamic approach enables quick transition between cells without requiring full RRC reconfiguration, reducing handover delay while maintaining communication quality.
2Adaptability or versatility
If CORESET configuration is updated frequently to support inter-cell mobility, then mobility management capability is improved, but system complexity and RRC signaling overhead increase
Solution Approach 1:
The patent pre-configures multiple TCI-States and associates them with different CORESETPoolIndexes before handover occurs. During handover, the system simply activates the pre-configured TCI-State corresponding to the target cell, avoiding complex real-time configuration updates and reducing both system complexity and signaling overhead.
Solution Approach 2:
The patent creates a universal HARQ-ACK codebook structure that can handle multiple CORESETPoolIndexes and TCI-States through a unified framework. This universal approach allows the system to manage inter-cell mobility with a single codebook mechanism rather than requiring separate codebooks for each cell, reducing overall system complexity.
3Productivity
If HARQ-ACK feedback is combined across multiple TRPs, then feedback efficiency is improved, but reliability decreases due to beam blockage from a single TRP
Solution Approach 1:
The patent segments the HARQ-ACK codebook into multiple groups, where each group corresponds to a specific CORESETPoolIndex and can be independently transmitted. This segmentation ensures that if one TRP's beam is blocked, the HARQ-ACK feedback for other TRPs remains intact, maintaining reliability while preserving feedback efficiency through structured organization.
Solution Approach 2:
The patent applies different feedback strategies to different parts of the codebook based on local conditions. Each codebook group is associated with specific TCI-States and can be transmitted through appropriate beams, ensuring that feedback reliability is optimized for each local TRP configuration while maintaining overall system efficiency.
Data Source
AI summary
The present disclosure provides a method and device used in nodes for wireless communications. The node firstly receives K information blocks, K being a positive integer greater than 1, each of the K information blocks comprises a first-type index and at least one second-type index; and then receives a first signaling and a second signaling respectively in a first resource set and a second resource set; and transmits first UCI in a physical layer channel on a first cell, the first cell being capable of bearing a HARQ-ACK associated with the first signaling; the first UCI comprises a HARQ-ACK associated with a second signaling. The present disclosure improves the method and device for design of HARQ-ACK codebook grouping to optimize the system performance.