Uplink Control Information Resource Allocation in Multi-Cell Wireless Systems
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Solution Overview
Problem
The increasing number of user equipment (UEs) and the corresponding uplink control information in wireless communication systems pose a challenge due to limited resources, necessitating an efficient method for the base station (BS) to receive uplink control information.
Innovation Solution
The method involves configuring multiple serving cells, including a primary cell (PCell) and secondary cells (SCells), and transmitting acknowledgement (ACK)/negative acknowledgement (NACK) information using a specific serving cell in the uplink subframe, allowing for efficient use of resources by dropping physical uplink shared channel (PUSCH) transmission and receiving ACK/NACK information on the physical uplink control channel (PUCCH) if necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple serving cells are configured to handle increasing uplink control information, then the system can support more user equipment and control channels, but the resource availability per cell decreases and complexity increases
Solution Approach 1:
The patent segments uplink control information by dividing it into two groups: first ACK/NACK information associated with the primary cell (PCell) and second ACK/NACK information associated with secondary cells (SCells). This segmentation allows independent handling and transmission strategies for each group, managing the increasing control information volume without proportionally increasing overall system complexity.
Solution Approach 2:
The patent introduces a new dimension for resource allocation by allowing ACK/NACK information to be transmitted on different uplink channels (PUCCH or PUSCH) depending on the information group and channel availability. This dimensional flexibility in transmission paths enables efficient resource utilization across multiple serving cells without linearly increasing system complexity.
2Quantity of substance
If physical uplink shared channel (PUSCH) transmission is maintained for data while also transmitting ACK/NACK information, then data transmission continues, but resource availability for control information decreases
Solution Approach 1:
The patent implements dynamic resource allocation where the transmission channel for ACK/NACK information (PUCCH or PUSCH) is determined based on real-time conditions including whether PUSCH transmission is configured and the group association of the ACK/NACK information. This dynamic approach optimizes resource availability by adaptively selecting transmission paths rather than statically dedicating resources.
Solution Approach 2:
The patent changes the transmission parameter (channel selection) based on the configuration state. When PUSCH transmission is configured for the first group, second ACK/NACK information is transmitted on PUCCH; when PUSCH is not configured or for first ACK/NACK information, PUSCH is used. This parameter change optimizes resource utilization by matching transmission mode to operational context.
3Reliability
If ACK/NACK information is transmitted on physical uplink control channel (PUCCH) by dropping PUSCH transmission, then control information reliability improves, but data transmission efficiency decreases
Solution Approach 1:
The patent applies partial action by selectively dropping PUSCH transmission only when necessary for specific ACK/NACK information groups (second group when PUSCH is configured for first group). This partial approach maintains data transmission for other channels and conditions, preserving overall system productivity while ensuring control information reliability where needed.
Solution Approach 2:
The patent applies different transmission strategies to different ACK/NACK information groups based on their association with specific cells. First ACK/NACK information (PCell) and second ACK/NACK information (SCells) are handled differently, allowing local optimization of reliability versus productivity trade-offs for each cell group rather than applying a uniform approach system-wide.
Data Source
AI summary
The present invention determines a PUCCH resource based on which serving cell ACK/NACK information is related to, when a user device set as a plurality of serving cells transmits the ACK/NACK information. Moreover, if a PUCCH transmission time matches with a PUSCH transmission time, the present invention does not piggy back ACK/NACK information to PUSCH but transmits the ACK/NACK information through PUCCH.