Transmit End Modulation Adjustment via Retransmission Feedback
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Solution Overview
Problem
In communications systems, the receive end's inaccurate SNR estimation leads to poor modulation adjustment at the transmit end, resulting in inefficient data transmission due to noise variations in channels.
Innovation Solution
The transmit end determines noise variation information based on unique initial signal-to-noise ratio margins of subchannels and adjusts the signal-to-noise ratio margins accordingly, allowing for accurate dynamic modulation parameter adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the receive end estimates SNR of the channel and feeds back the result to the transmit end for modulation parameter adjustment, then the transmit end can dynamically adjust modulation parameters, but the SNR estimation by the receive end is not accurate and cannot accurately reflect noise variation, resulting in poor modulation adjustment effect
Solution Approach 1:
The patent introduces an intermediary mechanism (retransmission request feedback) between the receive end and transmit end to indirectly measure noise variation. Instead of directly estimating SNR, the receive end's modulation failure triggers retransmission requests, which the transmit end uses as a proxy indicator to infer channel noise conditions and adjust modulation parameters accordingly.
Solution Approach 2:
The patent implements a feedback loop where the receive end sends retransmission requests based on modulation success/failure, and the transmit end uses this feedback to continuously adjust modulation parameters. This closed-loop feedback system enables adaptive modulation adjustment based on actual channel conditions rather than inaccurate direct SNR estimation.
2Productivity
If the transmit end adjusts modulation parameter based on receive end's SNR estimation result, then dynamic channel adaptation is achieved, but the modulation adjustment effect is poor due to inaccurate SNR estimation
Solution Approach 1:
The system uses its own operational outcomes (retransmission requests generated during normal communication) as the basis for adjustment decisions. The transmit end monitors its own modulation success rate through retransmission request feedback and autonomously adjusts modulation parameters without relying on external SNR estimates, making the system self-correcting and more reliable.
3Device complexity
If a single signal-to-noise ratio margin is used for all subchannels, then the system is simpler to manage, but it cannot accurately reflect different noise variations in different subchannels, reducing transmission efficiency
Solution Approach 1:
The patent segments the channel into multiple subchannels, each with its own signal-to-noise ratio margin. This segmentation allows independent optimization of each subchannel based on its specific noise characteristics, improving overall transmission efficiency while maintaining manageable complexity through systematic management of the segmented parameters.
Solution Approach 2:
The patent applies different signal-to-noise ratio margins to different subchannels based on their local noise conditions. Each subchannel receives a customized margin value tailored to its specific transmission characteristics, enabling localized optimization rather than applying a uniform margin across all subchannels.
Data Source
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AI summary
Embodiments of the present invention provide a transmit end modulation adjustment method and apparatus, and a transmit end. The transmit end modulation adjustment method includes: determining a retransmission request rate of each group of subchannels according to a retransmission request received through at least two groups of subchannels, determining at least one group of subchannels whose retransmission request rate is not a hundred percent, and determining noise variation information according to an initial signal-to-noise ratio margin of the at least one group of subchannels; and adjusting a signal-to-noise ratio margin of each group of subchannels at a receive end according to the noise variation information at the receive end. According to the transmit end modulation adjustment method and apparatus, and the transmit end provided in the embodiments of the present invention, accurate dynamic adjustment of a modulation parameter at the transmit end is achieved, thereby improving a transmission effect of a communications system.