PUCCH HARQ-ACK Mapping for Low-Latency Sub-Slot Feedback
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Solution Overview
Problem
Existing wireless communication systems face challenges in achieving low latency for HARQ-ACK feedback due to inefficient mapping of physical downlink shared channels (PDSCH) to physical uplink control channels (PUCCH), leading to excessive round trip times and limited flexibility in HARQ-ACK reporting.
Innovation Solution
Implementing sub-slot based HARQ-ACK codebooks and flexible PUCCH transmission characteristics, allowing for multiple PUCCH transmissions per sub-slot, including support for both 2x7-symbol and 7x2-symbol configurations, to enhance HARQ-ACK reporting efficiency and reduce latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If uplink control information is transmitted on a physical uplink shared channel, then resource utilization is improved, but transmission latency increases due to scheduling delays
Solution Approach 1:
The patent segments the uplink transmission into two distinct channels: PUSCH for bulk data transmission and PUCCH for urgent control information. This segmentation allows control information to be transmitted independently without waiting for PUSCH scheduling, thereby reducing latency while maintaining efficient resource utilization for data transmission.
Solution Approach 2:
The patent introduces PUCCH as an intermediary channel specifically for control information transmission. This intermediary bypasses the PUSCH scheduling mechanism, providing a dedicated path for control signals that eliminates scheduling delays and ensures timely transmission of control information.
2Loss of time
If control information is transmitted on a physical uplink control channel, then transmission latency is reduced, but resource utilization efficiency decreases
Solution Approach 1:
The patent applies local quality by allocating specific time-frequency resources exclusively for PUCCH transmission. This dedicated resource allocation ensures that control information receives the necessary resources without contending for bandwidth with data transmissions, optimizing control channel performance while maintaining overall system efficiency.
Solution Approach 2:
The patent implements partial action by allocating only the necessary resources for control information transmission through PUCCH, rather than requiring full PUSCH scheduling. This partial resource allocation reduces latency for control information while minimizing the impact on overall resource utilization efficiency.
3Reliability
If multiple transmissions are combined to achieve target code rate, then coding gain is improved, but transmission time increases
Solution Approach 1:
The patent applies preliminary action by performing code rate matching and combining operations in advance during the PUCCH transmission process. This allows the system to achieve the required coding gain through pre-computed combinations of control information transmissions, reducing the need for additional retransmissions and minimizing overall transmission time.
Data Source
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AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may determining a physical uplink control channel (PUCCH) transmission characteristic, wherein the PUCCH transmission characteristic is a quantity of PUCCH transmissions in a sub-slot or a format of a set of PUCCH transmissions in the sub-slot, and wherein the wireless communication device supports at least one sub-slot hybrid automatic repeat request (HARQ) acknowledgement (ACK) codebook; and reporting information identifying the PUCCH characteristic for a plurality of types of symbol codebooks. Numerous other aspects are provided.