Uplink Control Information Transmission in TDD Carrier Aggregation
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in transmitting control information, particularly in Time Division Duplex (TDD) systems, where resource management for uplink control information is challenging due to differing configurations between cells.
Innovation Solution
A method for transmitting uplink control information in a wireless communication system supporting carrier aggregation in TDD, involving the generation of HARQ-ACK sets for multiple cells and transmitting a combined bit value in an uplink subframe, where the maximum value between cells determines the number of downlink subframes corresponding to the uplink subframe, allowing efficient resource management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate HARQ-ACK sets are generated for each cell with different UL-DL configurations, then each cell can be managed independently, but the overall control information transmission becomes complex and resource management becomes difficult
Solution Approach 1:
The patent merges multiple HARQ-ACK sets from different cells into a single unified HARQ-ACK message for transmission in the uplink subframe. This combining approach reduces the number of separate transmissions needed while maintaining the ability to handle different UL-DL configurations through the use of a common value M that determines the number of downlink subframes for resource allocation.
Solution Approach 2:
The patent creates a universal resource allocation mechanism using value M that works across cells with different UL-DL configurations. This single value M serves multiple functions: it determines the number of downlink subframes for multiple cells simultaneously, enables unified PUCCH resource allocation, and provides a common framework for HARQ-ACK transmission across heterogeneous cell configurations.
2Productivity
If the number of downlink subframes is determined separately for each cell, then each cell's specific configuration is optimized, but resource management across aggregated cells becomes inefficient
Solution Approach 1:
The patent changes the parameter approach from cell-specific downlink subframe counts to a unified value M that applies across all aggregated cells. This parameter change enables efficient resource management by allowing the system to handle different UL-DL configurations through a single controlling parameter that determines PUCCH resource allocation for all cells simultaneously.
3Reliability
If multiple PUCCH resources are allocated for different cells, then each cell's control information can be transmitted independently, but resource overhead and system complexity increase
Solution Approach 1:
The patent combines multiple cell-specific HARQ-ACK transmissions into a single unified PUCCH transmission. By merging the control information from multiple cells into one message transmitted on a single PUCCH resource, the system reduces resource overhead while maintaining reliability through the unified transmission approach.
Data Source
AI summary
A wireless communication system is disclosed. A method for transmitting uplink control information in a wireless communication system supporting carrier aggregation and operating in TDD includes: generating a first HARQ-ACK (hybrid automatic repeat request—acknowledgement) set for a first cell using a value M; generating a second HARQ-ACK set for a second cell using the value M; and transmitting a bit value corresponding to a third HARQ-ACK set including the first HARQ-ACK set and the second HARQ-ACK set in an uplink subframe n, wherein M=max(M1, M2), max(M1, M2) representing a value being equal to or larger than not smaller between M1 and M2, wherein M1 corresponds to the number of downlink subframes corresponding to the uplink subframe n in the first cell, and M2 corresponds to the number of downlink subframes corresponding to the uplink subframe n in the second cell, wherein the first cell and the second cell have different UL-DL configurations.