PUCCH Format Selection for ACK/NACK Feedback in Wireless Systems
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Solution Overview
Problem
The existing 3GPP LTE-A wireless communication systems face challenges in efficiently managing and transmitting ACK/NACK feedback information with an increased number of serving cells, as they only provide three PUCCH formats, which are insufficient for handling larger payload sizes and varying channel conditions.
Innovation Solution
A method and device for selecting and transmitting ACK/NACK using either a first PUCCH format with 24 data symbols or a second PUCCH format with more than 24 data symbols, based on the size of the ACK/NACK information, to optimize the physical uplink control channel (PUCCH) format for efficient feedback transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of serving cells is increased to support more users and services, then the system capacity and data rate are improved, but the amount of feedback information (ACK/NACK) increases, requiring more PUCCH formats which increases device complexity
Solution Approach 1:
The patent changes the parameter of PUCCH format selection by introducing a new criterion based on the number of transport blocks. Specifically, when the number of transport blocks is 2 or more, PUCCH format 3 is selected; when the number is 1, PUCCH format 1a/1b is selected. This parameter-based selection rule simplifies the complexity of supporting multiple serving cells by providing a clear, automated decision mechanism.
2Adaptability or versatility
If more PUCCH formats with different payload sizes are introduced to handle increased feedback information, then the adaptability to different payload sizes is improved, but the device complexity and difficulty of format selection increase
Solution Approach 1:
The patent introduces a clear parameter-based selection rule: when the number of transport blocks is 2 or more, PUCCH format 3 is selected; when the number is 1, PUCCH format 1a/1b is selected. This straightforward parameter threshold approach provides adaptability to different payload sizes while keeping the selection process simple and deterministic.
Solution Approach 2:
The system enables self-service by allowing the terminal to automatically select the appropriate PUCCH format based on the number of transport blocks it needs to feedback. The terminal itself performs the selection without requiring complex external control or configuration, making the system adaptive while minimizing control overhead.
3Quantity of substance
If the number of data symbols in PUCCH format is increased to accommodate larger ACK/NACK payloads, then the information transmission capacity is improved, but the resource consumption and interference to other channels increase
Solution Approach 1:
The patent segments the ACK/NACK feedback into different PUCCH formats based on the number of transport blocks. For small payloads (1 transport block), it uses PUCCH format 1a/1b with fewer data symbols, conserving uplink resources. For larger payloads (2 or more transport blocks), it uses PUCCH format 3 with more data symbols, ensuring sufficient capacity. This segmentation approach optimizes resource consumption by matching the PUCCH format to the actual feedback size.
Data Source
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AI summary
Provided are a method for transmitting an ACK/NACK in a wireless communication system and a device using the same. The device receives a plurality of DL transmission blocks from a plurality of serving cells, and according to ACK/NACK information for the plurality of DL transmission block, selects a physical uplink control channel (PUCCH) format.