HARQ-ACK Retransmission Timing Using MCS Field Offsets
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Solution Overview
Problem
Existing wireless communication systems face challenges in managing downlink control information (DCI) size, spectrum efficiency, implementation complexity, and reliability of Hybrid Automatic Repeat Request-Acknowledgement (HARQ-ACK) transmission, particularly in high-frequency bands like terahertz bands of 6G mobile communication technologies.
Innovation Solution
The method involves receiving configuration information for HARQ-ACK retransmission via higher layer signaling, identifying an offset for the retransmission using a modulation and coding scheme (MCS) field in DCI, and performing the retransmission on a slot identified by this offset, thereby optimizing HARQ-ACK behavior and ensuring consistency between the UE and the base station.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the DCI format includes separate fields for HARQ-ACK retransmission timing indication, then the timing accuracy is improved, but the DCI size increases
Solution Approach 1:
The patent combines the HARQ-ACK retransmission timing indication with the existing MCS field in DCI. By merging these functions into a single field, the patent achieves accurate timing indication without increasing the overall DCI size, thus resolving the contradiction between timing precision and control overhead.
Solution Approach 2:
The MCS field in DCI is given multi-functionality by using it to indicate both modulation and coding scheme information and HARQ-ACK retransmission timing. This allows the same field to serve multiple purposes, eliminating the need for separate timing indication fields and reducing DCI overhead while maintaining timing accuracy.
2Reliability
If configuration information for HARQ-ACK retransmission is transmitted via higher layer signaling, then the reliability is improved, but the implementation complexity increases
Solution Approach 1:
The patent segments the configuration information transmission into two parts: essential parameters are configured via higher layer signaling for reliability, while dynamic timing information is conveyed through physical layer DCI for efficiency. This segmentation reduces overall implementation complexity while maintaining reliability for critical parameters.
Solution Approach 2:
The patent introduces an intermediary mechanism where the MCS field in DCI acts as a mediator between higher layer configuration and physical layer HARQ-ACK retransmission timing. This intermediary allows efficient physical layer operation while relying on reliable higher layer configuration, balancing reliability and complexity.
3Productivity
If the MCS field is reused for timing indication, then the spectrum efficiency is improved, but the measurement precision of MCS may be affected
Solution Approach 1:
The patent applies dynamics by allowing the interpretation of the MCS field to change based on context. When HARQ-ACK retransmission timing indication is needed, the field dynamically serves that purpose; otherwise, it maintains its traditional MCS function. This dynamic usage optimizes spectrum efficiency without permanently sacrificing MCS precision.
Solution Approach 2:
The patent changes the parameter interpretation of the MCS field based on operational context. By dynamically adjusting what the field represents (either MCS parameters or timing offset), the system achieves spectrum efficiency through field reuse while maintaining the precision needed for actual MCS transmission when required.
Data Source
AI summary
Methods and apparatuses are provided in a wireless communication system. Configuration information regarding a hybrid automatic repeat and request-acknowledgement (HARQ-ACK) retransmission is received from a base station (BS) via higher layer signaling. Downlink control information (DCI) is received from the BS. An offset for the HARQ-ACK retransmission is identified as a value of a modulation and coding scheme (MCS) field included in the DCI, based on the configuration information. The HARQ-ACK retransmission is performed on a slot identified based on the offset.