Uplink Control Information Transmission in TDD Carrier Aggregation
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Solution Overview
Problem
Wireless communication systems face inefficiencies in transmitting uplink control information in Time Division Duplexing (TDD) systems, particularly in managing resources and accurately acknowledging downlink signals across multiple subframes and component carriers.
Innovation Solution
A method and apparatus for efficiently transmitting uplink control information by determining the number of ACK/NACK bits using a predetermined 2-bit field in the DCI format, incorporating the value indicated by the VDAIUL and ceiling function, and transmitting this information through the PUSCH, while also considering the number of PDSCH and PDCCH signals received across multiple downlink subframes and component carriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of ACK/NACK bits is increased to acknowledge more downlink signals in TDD systems with carrier aggregation, then the reliability of downlink acknowledgment is improved, but the uplink control channel resource consumption increases
Solution Approach 1:
The patent segments the ACK/NACK feedback by introducing a counter DAI (Downlink Assignment Index) that divides the acknowledgment process into manageable units corresponding to different downlink subframes and component carriers. This segmentation allows the system to handle multiple downlink signals systematically while controlling the total feedback size.
Solution Approach 2:
The patent adds temporal and frequency dimensions to the ACK/NACK feedback structure by incorporating counter DAI values that track downlink assignments across multiple subframes and component carriers. This multi-dimensional approach enables efficient resource management while maintaining comprehensive acknowledgment coverage.
2Productivity
If the system supports more component carriers and downlink subframes, then the system capacity and throughput are improved, but the complexity of managing ACK/NACK feedback increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring the counter DAI values in downlink assignments before ACK/NACK feedback is generated. This allows the UE to systematically track and manage downlink assignments across multiple component carriers and subframes, reducing the complexity of feedback management while supporting higher system capacity.
3Measurement precision
If the ACK/NACK feedback includes all received PDCCH and PDSCH signals, then the measurement precision of downlink signal acknowledgment is improved, but the transmission time and resource overhead increase
Solution Approach 1:
The patent introduces the counter DAI as an intermediary element that bridges downlink assignments and uplink ACK/NACK feedback. This intermediary tracks the number of received PDCCH and PDSCH signals systematically, ensuring accurate acknowledgment while enabling efficient resource allocation and reducing feedback transmission overhead through structured reporting.
Data Source
AI summary
A method and a communication device are described for transmitting uplink control information in a wireless communication system supporting carrier aggregation. At least one of a plurality of physical downlink control channels (PDCCHs) indicating downlink semi-persistent scheduling (SPS) release or physical downlink shared channels (PDSCHs) is received in a plurality of downlink subframes according to an uplink (UL)- downlink (DL) configuration for time division duplex (TDD);. A PDCCH with a downlink control information (DCI) format for UL scheduling including a 2-bit field is received. Acknowledgement (ACK)/negative acknowledgement (NACK) information corresponding to the at least one PDCCH indicating downlink SPS release or the PDSCHs is transmitted through a physical uplink shared channel (PUSCH) based on the received PDCCH with the DCI format for UL scheduling.