ARQ Status Report Timing Alignment in Mobile Communication
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Solution Overview
Problem
In mobile communication systems, the combination of ARQ and HARQ often results in unnecessary retransmissions due to inaccuracies in estimating the occurrence time of status reports, particularly because the HARQ ACK/NACK signal reliability is low and scheduling delays can misalign the status report generation and transmission times.
Innovation Solution
The ARQ receiving entity generates and sends status reports at a transmission opportunity indicated by the HARQ processor, and the ARQ transmitting entity estimates the status report occurrence time by accounting for scheduling delays, ensuring that the status report generation time is aligned with the transmission time, thereby preventing unnecessary retransmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the ARQ receiving entity sends status reports at transmission opportunities indicated by the HARQ processor, then the transmission timing is optimized for system efficiency, but the status report generation time may be misaligned with the actual reception time, causing inaccuracies in estimating the occurrence time
Solution Approach 1:
The ARQ receiving entity generates the status report in advance at the actual reception time of the HARQ packet, before the transmission opportunity indicated by the HARQ processor. This preliminary generation ensures that the status report occurrence time accurately reflects when the packet was actually received, while still allowing transmission at the optimal system-scheduled time without causing timing misalignment errors.
2Device complexity
If the system uses HARQ scheduling to manage transmissions, then resource allocation is optimized, but scheduling delays cause misalignment between status report generation and transmission times
Solution Approach 1:
The status report is generated preliminarily at the actual reception time of the HARQ packet, before the scheduling delay occurs. The HARQ processor then transmits the packet containing the status report at the scheduled transmission opportunity. This approach eliminates timing misalignment errors because the status report occurrence time accurately reflects the actual reception time, not the delayed transmission time.
3Ease of operation
If the ARQ transmitting entity estimates status report occurrence time based on HARQ packet reception time, then the estimation process is simplified, but the reliability of the estimate decreases due to low HARQ ACK/NACK signal reliability
Solution Approach 1:
The patent extracts the status report generation from the HARQ transmission timing and anchors it to the actual HARQ packet reception time at the ARQ receiving entity. This separation ensures that the status report occurrence time is determined by the reliable actual reception event rather than the unreliable HARQ ACK/NACK signaling or scheduled transmission time, thereby improving estimation reliability while maintaining process simplicity.
Data Source
AI summary
Methods and apparatuses are provided for transmitting a status report by a receiving device including an automatic repeat request (ARQ) entity and a hybrid ARQ (HARQ) processor, in a mobile communication system. The method includes transmitting, by the HARQ processor, a packet provided from the ARQ entity to a receiving device; receiving, by the HARQ processor, a packet including a status report including a reception status of the transmitted packet from the receiving device; and providing, by the HARQ processor, the status report to the ARQ entity. The status report is generated, by an ARQ entity of the receiving device at a transmission opportunity indicated by a HARQ processor of the receiving device, in response to the status report being triggered based on at least one triggering condition by the ARQ entity of the receiving device.