HARQ-ACK Resource Allocation Using TPC and DAI Indices
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Solution Overview
Problem
There is a need to reduce resource overhead and avoid collisions for Hybrid Automatic Repeat Request (HARQ-ACK) signal transmissions in wireless communication systems, particularly in scenarios with multiple Component Carriers (CCs) or sub-frames, where existing methods result in inefficient resource allocation and potential collisions among User Equipment (UEs).
Innovation Solution
The method involves using Transmission Power Control (TPC) and Downlink Assignment Index (DAI) Information Elements in Downlink Control Information (DCI) to determine the resource allocation for HARQ-ACK signal transmissions, where the TPC IE adjusts transmission power and the DAI IE indicates the relative order of DL SAs, allowing UEs to efficiently select resources for HARQ-ACK signal transmission based on configured resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate resources are allocated for HARQ-ACK signal transmission in response to DL SA reception in multiple DL CCs, then the reliability of HARQ-ACK transmission is improved, but the resource overhead increases
Solution Approach 1:
The patent merges the resource allocation for HARQ-ACK signals from multiple DL CCs into a single UL CC. Instead of allocating separate resources in each DL CC, the invention combines all HARQ-ACK transmissions into one uplink carrier, reducing overall resource overhead while maintaining reliable acknowledgment of downlink assignments across multiple carriers.
Solution Approach 2:
The patent makes a single UL CC resource serve multiple functions by using it to transmit HARQ-ACK signals for multiple DL CCs. This multi-functional approach allows one uplink resource to handle acknowledgments for several downlink carriers, reducing the total number of resources needed while improving resource utilization efficiency.
2Productivity
If multiple UEs transmit HARQ-ACK signals simultaneously in the same resource, then the productivity of the system is improved, but collisions occur among UEs
Solution Approach 1:
The patent introduces the TPC IE from DCI as an intermediary mechanism to mediate resource allocation among multiple UEs. The TPC field, originally intended for power control, is repurposed to indicate resource offsets, acting as a mediator that resolves potential collisions by assigning unique resource positions to different UEs based on their respective DCI assignments.
Solution Approach 2:
The patent implements dynamic resource allocation where the HARQ-ACK resource position is determined by the TPC IE value in each UE's DCI. This dynamic approach allows resources to be flexibly assigned based on current system conditions and UE-specific parameters, enabling multiple UEs to transmit simultaneously without fixed collision patterns while maintaining high system productivity.
Data Source
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AI summary
A method for transmitting, by a user equipment, a hybrid automatic repeat request acknowledgement, HARQ-ACK, the method comprising: identifying power of the HARQ-ACK based on transmission power control information in first downlink control information for a primary cell; identifying, for a time division duplexing, TDD, and a plurality of configured cells, a resource for transmission of the HARQ-ACK based on transmission power control information in second downlink control information with a downlink assignment index, DAI, value greater than 1; and transmitting the HARQ-ACK based on the resource on the primary cell.