Dynamic HARQ-ACK Codebook Sizing for Lower Feedback Overhead

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Traditional semi-static HARQ-ACK codebooks in wireless communication have high overhead, which affects the performance of wireless communication systems.

Innovation Solution

Implementing a dynamic HARQ-ACK codebook generation method that determines HARQ-ACK information based on parameters in DCI, such as parameter A, to reduce the number of bits required for feedback, using techniques like bitmap signaling and high-level signaling (RRC or MAC CE) to optimize codebook size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If traditional semi-static HARQ-ACK codebook is used, then feedback reliability is maintained, but overhead is excessive

Engineering Contradiction:

Improvecodebook overheadVSAvoidfeedback reliability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent transitions from a static codebook size to a dynamic codebook size that adapts to actual PDSCH transmission conditions. The codebook size is determined based on whether PDSCH was transmitted in a given slot, allowing the feedback overhead to vary dynamically rather than remaining fixed, thus reducing unnecessary overhead while maintaining reliability for actual transmissions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of codebook size from a fixed semi-static configuration to a variable parameter that is determined based on transmission conditions. By making the codebook size dependent on whether PDSCH was transmitted, the system optimizes the feedback overhead parameter to match actual needs, reducing waste while ensuring sufficient feedback capacity when transmissions occur.

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If dynamic HARQ-ACK codebook generation method is implemented, then overhead is reduced, but codebook determination complexity increases

Engineering Contradiction:

Improvefeedback bitsVSAvoidcodebook determination complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring UE with parameters and rules for codebook determination through higher-layer signaling before actual transmission occurs. The UE is pre-provided with the necessary information (such as PDSCH transmission indicators) so that during operation, the codebook size can be quickly determined using simple lookup or pre-established logic, avoiding complex real-time calculations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The UE autonomously determines the codebook size based on pre-configured parameters and transmission conditions without requiring complex external computation or signaling. The self-service mechanism allows the UE to independently assess whether PDSCH was transmitted and accordingly select the appropriate codebook size using simple determination logic, reducing overall system complexity while achieving overhead reduction.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS20260025251A1HARQ-ACK codebook management method, apparatus, and computer readable storage medium

Publication Date: 2026.01.22 ZTE CORP

AI summary

Wireless communication methods are disclosed. A wireless communication method includes determining, by user equipment (UE), HARQ-ACK information of an HARQ-ACK codebook of at least one corresponding PDSCH group according to at least one of: at least one piece of first-formatted piece DCI (downlink control information), a parameter, a first signaling, a configuration of the UE, or a preset rule; and sending the HARQ-ACK codebook to a base station (BS).