N-bit Field Segmentation for UL-DL Configuration in Carrier Aggregation
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Solution Overview
Problem
Carrier aggregation-based wireless communication systems face challenges in efficiently transmitting control information and acknowledgement information on downlink/uplink signals, particularly due to variations in subframe configurations and the need for accurate timing and indexing in UL-DL configurations.
Innovation Solution
The method involves configuring user equipment (UE) with different subframe configurations for first and second cells, using an N-bit field in the UL DCI format to determine subframe indices or indicate downlink assignment indices, depending on the UL-DL configuration, allowing efficient transmission of physical uplink shared channel (PUSCH) signals and HARQ-acknowledgement payloads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple cells with different subframe configurations are configured in carrier aggregation, then system capacity and flexibility are improved, but control information transmission complexity and timing alignment difficulty increase
Solution Approach 1:
The patent segments the N-bit field in UL DCI format into different functional parts depending on the UL-DL configuration. For configuration #0, the field is segmented to determine subframe index; for configurations #1-6, the field is segmented to indicate downlink assignment index (DAI). This segmentation allows the same N-bit field to serve different purposes in different configurations, reducing overall system complexity while maintaining flexibility.
Solution Approach 2:
The patent implements dynamic interpretation of the N-bit field based on the configured UL-DL configuration. The meaning and usage of the N-bit field dynamically changes: in configuration #0 it determines subframe index for PUSCH timing, while in configurations #1-6 it indicates DAI for HARQ-ACK payload generation. This dynamic adaptation resolves the contradiction by allowing one field to serve multiple functions without increasing transmission complexity.
2Manufacturing precision
If N-bit field is used to determine subframe index in UL-DL configuration #0, then PUSCH timing accuracy is improved, but interpretation complexity across different configurations increases
Solution Approach 1:
The patent applies local quality by tailoring the interpretation of the N-bit field to the specific UL-DL configuration being used. For UL-DL configuration #0, the N-bit field is interpreted locally as subframe index to achieve accurate PUSCH timing. For UL-DL configurations #1-6, the same N-bit field is locally interpreted as downlink assignment index for HARQ-ACK payload generation. This localized interpretation approach maintains timing accuracy where needed while avoiding unnecessary complexity in other configurations.
3Manufacturing precision
If N-bit field indicates downlink assignment index in UL-DL configurations #1-6, then HARQ-ACK payload accuracy is improved, but timing determination complexity increases
Solution Approach 1:
The patent implements universality by designing the N-bit field to serve multiple functions across different UL-DL configurations. The same N-bit field structure is used universally, but its function adapts: in configurations #1-6 it indicates downlink assignment index for accurate HARQ-ACK payload generation, while in configuration #0 it determines subframe index for timing. This multi-functionality approach improves accuracy in each specific case without requiring separate fields or increasing overall complexity.
Data Source
AI summary
The present invention relates to a wireless communication system. More particularly, the present invention relates to a method in which a terminal transmits control information in a CA-based wireless communication system and to an apparatus for the method, the method comprising: a step of configuring a first cell and a second cell having different subframe configurations, the second cell has UL-DL configuration #0; a step of receiving a downlink control information (DCI) format including an N-bit field (N>1), for the second cell; and a step of transmitting a physical uplink shared channel (PUSCH) signal corresponding to the downlink DCI format through a subframe. The N-bit field indicates either an uplink (UL) index or a downlink assignment index (DAI). For PUSCH timing, in cases where a reference UL-DL configuration applied to the second cell is any one of UL-DL configurations #1 to #6, the N-bit field indicates the DAI.