ACK/NACK Bundling in Multi-Carrier PUCCH Format 1b
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Solution Overview
Problem
In multi-carrier wireless communication systems, existing technologies face challenges in efficiently transmitting acknowledgment (ACK) and negative acknowledgment (NACK) feedback with scheduling requests, particularly in LTE systems, where the number of ACK/NACK bits can become significant due to downlink transmissions on multiple component carriers, leading to limited uplink resources and increased overhead.
Innovation Solution
The solution involves bundling ACK/NACK feedback across multiple component carriers, using techniques such as spatial bundling and mapping of ACK instances to bit values, allowing for increased effective bits to be conveyed using available scheduling request (SR) resources, particularly through PUCCH Format 1b messages, which enables efficient transmission of ACK/NACK feedback even with limited resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ACK/NACK feedback is transmitted for each component carrier separately, then feedback granularity is improved, but uplink resource consumption increases
Solution Approach 1:
The patent segments ACK/NACK feedback transmission by introducing separate PUCCH resources for different feedback types (ACK-only, NACK-only, ACK/NACK combinations). This allows the system to maintain fine-grained feedback for each component carrier while optimizing resource usage by grouping similar feedback patterns together, thus resolving the contradiction between feedback granularity and resource consumption.
Solution Approach 2:
The patent introduces a new dimension to feedback transmission by adding a resource selection dimension. Instead of transmitting all feedback on a single resource, the system selects from multiple PUCCH resources based on the feedback pattern, effectively increasing the information capacity without proportionally increasing resource consumption. This dimensional approach allows efficient scaling with the number of component carriers.
2Quantity of substance
If the number of PUCCH resources is increased to support more component carriers, then feedback capacity is improved, but system complexity increases
Solution Approach 1:
The patent makes PUCCH resources universal by designing them to handle multiple feedback types (ACK, NACK, DTX) and multiple component carrier configurations. Each PUCCH resource can serve different purposes depending on the feedback pattern, reducing the total number of resources needed compared to having dedicated resources for each feedback type and carrier combination.
Solution Approach 2:
The patent changes the parameter of resource allocation from static to dynamic, where the selected PUCCH resource depends on the actual feedback pattern generated. This parameter change allows the system to adapt resource usage to actual needs, increasing feedback capacity without proportionally increasing the configured resource pool size.
3Productivity
If ACK/NACK bundling is applied across multiple component carriers, then resource efficiency is improved, but feedback precision deteriorates
Solution Approach 1:
The patent introduces dynamic feedback reporting where the level of bundling varies based on channel conditions and traffic patterns. The system can switch between bundled and non-bundled feedback modes, allowing it to optimize between resource efficiency and feedback precision dynamically rather than using a fixed bundling approach.
Solution Approach 2:
The patent applies partial bundling where only certain component carriers or certain feedback types are bundled while others remain separate. This selective approach maintains precision for critical feedback (e.g., NACKs that require retransmission) while applying bundling to less critical feedback to improve resource efficiency.
Data Source
AI summary
Methods, systems, devices, and computer program products are described which facilitate the transmission and reception of acknowledgment/negative acknowledgment (ACK/NACK) feedback associated with downlink data transmissions in a multi-carrier wireless communication system. Scheduling request resources may be utilized to enable the transmission of ACK/NACK feedback for the multiple component carriers when a positive scheduling request is present and the techniques described may be utilized to improve the efficiency of control channel signaling in different system configurations.