Cross-Carrier HARQ Retransmission Scheduling
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Solution Overview
Problem
In communication technologies, when user equipment (UE) fails to receive data from a base station, existing hybrid automatic repeat request (HARQ) systems often retransmit on the original carrier, which can fail due to limited channel resources in unlicensed frequency bands, leading to unsuccessful retransmissions.
Innovation Solution
The proposed method involves generating and sending a retransmission scheduling instruction to switch the retransmission to a different carrier, allowing for cross-carrier HARQ, where the base station generates a retransmission scheduling instruction after receiving failure indication from the UE and sends it on a second carrier, indicating retransmission on a third carrier, thereby optimizing resource usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If retransmission is performed on the original carrier, then the HARQ process is simple, but the retransmission success rate is low due to limited channel resources in unlicensed frequency bands
Solution Approach 1:
The patent introduces cross-carrier retransmission, moving the retransmission from the same frequency domain (original carrier) to a different frequency domain (different carrier). This dimensional change in the frequency domain allows the system to overcome channel resource limitations by utilizing alternative carriers, thereby improving retransmission success rate while managing complexity through standardized procedures.
2Reliability
If cross-carrier retransmission is implemented, then the retransmission success rate improves, but the system complexity increases
Solution Approach 1:
The patent creates a universal HARQ mechanism that can operate in multiple modes: same-carrier retransmission and cross-carrier retransmission. The system maintains a unified HARQ process framework that adapts to different transmission scenarios, allowing it to function universally across various carrier configurations without requiring separate specialized systems for each mode.
Solution Approach 2:
The patent introduces scheduling instructions as an intermediary mechanism that coordinates cross-carrier retransmission. These scheduling instructions act as a mediator between the original carrier transmission and the alternative carrier retransmission, managing the complexity by providing a standardized control interface that simplifies the coordination between multiple carriers.
3Reliability
If retransmission is performed on the same carrier, then the scheduling is simple, but the channel resource limitations in unlicensed bands cause transmission failures
Solution Approach 1:
The patent implements a dynamic scheduling mechanism that can adaptively select between same-carrier and cross-carrier retransmission based on channel conditions and resource availability. This dynamic approach allows the system to switch transmission strategies flexibly, maintaining operational simplicity through automated decision-making while improving reliability by choosing the most suitable carrier for retransmission.
Data Source
AI summary
The present invention relates to a hybrid automatic repeat request (HARQ) method and a device. The method comprises: receiving, on a first carrier of multiple carriers, failure indication information sent by user equipment (UE) indicating a transmission failure of downlink data, and then generating a retransmission scheduling command; and sending the retransmission scheduling command to the UE on a second carrier, wherein the retransmission scheduling command comprises retransmission indication information for performing a retransmission on a third carrier, wherein the first carrier and the second carrier are the same carrier or different carriers, the second carrier and the third carrier are the same carrier or different carriers, and the first carrier and the third carrier are different carriers.