HARQ Feedback Codebook Handling for SBFD Multi-PDSCH Reception

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In 5G communication systems, the increased interference and reduced resource blocks in Subband-Fully-Duplex (SBFD) symbols lead to higher error rates for physical downlink shared channels (PDSCH), complicating hybrid automatic repeat request (HARQ) feedback due to unpredictable interference and differing antenna configurations.

Innovation Solution

A method for HARQ feedback in user equipment (UE) involving receiving configurations for symbol types, determining reception behaviors, and performing binary AND operations on HARQ-ACK information bits based on symbol type and time domain resource allocations to mitigate interference and error rates, using type-1 and type-2 HARQ-ACK codebooks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the BS transmits and receives simultaneously in SBFD symbols, then resource utilization is improved, but self-interference increases requiring complex antenna configurations

Engineering Contradiction:
Improveresource utilizationVSAvoidantenna configuration
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the HARQ feedback process into separate handling for SBFD and non-SBFD symbols. The network configures different reception behaviors for different symbol types, allowing the UE to apply specific HARQ feedback rules (such as different codebook types or feedback timing) tailored to each symbol type's characteristics, thereby managing the complexity introduced by simultaneous transmission and reception in SBFD symbols

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic adaptation by allowing the network to configure reception behaviors that can be restricted to specific symbol types. The UE dynamically adjusts its HARQ feedback generation and transmission based on the symbol type (SBFD or non-SBFD) and the configured reception behavior, enabling flexible response to changing interference conditions while maintaining efficient resource utilization

Inventive Principle:
Principle #15Dynamics

2Productivity

If PDSCH is transmitted in SBFD symbols, then resource utilization is improved, but error rate increases due to interference and reduced resource blocks

Engineering Contradiction:
Improveresource utilizationVSAvoiderror rate
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The network performs preliminary configuration by providing the UE with reception behavior configurations, multi-PDSCH reception configurations, and HARQ ACK codebook type configurations before PDSCH transmission. This allows the UE to pre-prepare appropriate HARQ feedback mechanisms based on the expected symbol type and interference conditions, improving reliability through proactive error management

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameters of HARQ feedback based on symbol type. For SBFD symbols, the network can configure different HARQ ACK codebook types (type1 or type2), different feedback timing, or even restrict reception behavior to exclude SBFD symbols from certain HARQ processes. These parameter changes allow the system to adapt to the higher error rates in SBFD symbols while maintaining overall resource utilization

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If binary AND operation is performed on PDSCH decoding results from SBFD and non-SBFD symbols, then HARQ ACK information is generated, but the impact of higher error rates in SBFD symbols affects overall accuracy

Engineering Contradiction:
ImproveHARQ feedback generationVSAvoidHARQ ACK accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent segments the HARQ feedback generation process by symbol type. Instead of uniformly applying binary AND operation to all PDSCH decoding results, the network can configure separate reception behaviors for SBFD and non-SBFD symbols. This allows the UE to generate HARQ ACK information bits separately for each symbol type or apply different processing rules, preventing the higher error rates in SBFD symbols from disproportionately affecting the overall HARQ ACK accuracy

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The network configuration acts as an intermediary that mediates between the raw PDSCH decoding results and the final HARQ ACK information. By introducing configurable reception behaviors and codebook types, the network can filter, weight, or separately process decoding results from SBFD symbols before combining them with non-SBFD results, thereby mitigating the impact of SBFD-related errors on overall HARQ feedback accuracy

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4693984A1Method of HARQ feedback and user equipment using the same
Publication Date: 2026.02.11 IND TECH RES INST
  • EP4693984A1 patent drawingFigure 1
  • EP4693984A1 patent drawingFigure 2
  • EP4693984A1 patent drawingFigure 3

AI summary

A method of hybrid automatic repeat request (HARQ) feedback and a user equipment are provided. The method includes: receiving a first configuration from a network, wherein the first configuration indicates a reception behavior; receiving a second configuration from the network, wherein the second configuration indicates a multiple physical downlink shared channels (multi-PDSCHs) reception; receiving a third configuration from the network, wherein the third configuration indicates a HARQ acknowledgment (ACK) codebook type; and transmitting a HARQ feedback according to the first configuration, the second configuration, and the third configuration.