Downlink Assignment Index for Multicarrier Feedback Bundling
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Solution Overview
Problem
In wireless communication systems, particularly in SC-FDMA and relaxed SC-FDMA, there is ambiguity in communicating retransmission feedback for multiple single carrier assignments, making it difficult to determine whether a downlink resource grant is received or lost, which affects the accuracy of HARQ feedback.
Innovation Solution
The use of a Downlink Assignment Index (DAI) to specify an index or identifier for each downlink resource grant, allowing for the detection of missing grants and bundling of feedback parameters based on power requirements to reduce transmission power, thereby clarifying the feedback process and improving resource management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If feedback for multiple carriers is transmitted separately, then feedback accuracy is improved, but transmission power consumption increases
Solution Approach 1:
The patent combines feedback for multiple carriers into a single bundled feedback transmission. Instead of sending separate feedback messages for each carrier, the system aggregates the feedback information and transmits it together, reducing the number of transmissions and associated power consumption while maintaining feedback accuracy through proper indication mechanisms.
2Use of energy by moving object
If feedback parameters are bundled, then transmission power is reduced, but ambiguity in detecting lost downlink resource grants increases
Solution Approach 1:
The patent introduces a Downlink Assignment Index (DAI) as an intermediary element within the bundled feedback. The DAI carries indication information about the number of downlink resource grants and their sequence, enabling the receiver to detect lost grants unambiguously even when feedback parameters are bundled together. This intermediary structure resolves the ambiguity problem while preserving the power-saving benefits of bundling.
3Measurement precision
If separate feedback is transmitted for each carrier, then lost grant detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent implements a universal DAI structure that can handle feedback for multiple carriers simultaneously. The DAI is designed to work across different carrier configurations and feedback scenarios, providing a single standardized mechanism for lost grant detection that replaces the need for carrier-specific detection procedures, thereby reducing device complexity while maintaining detection accuracy.
Data Source
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AI summary
Systems and methodologies are described that facilitate indicating feedback parameters for multiple single carrier assignments, multicarrier assignments, and/or the like according to single carrier-frequency division multiple access (SC-FDMA), relaxed SC-FDMA, etc. Feedback in relaxed SC-FDMA can be bundled by a mobile device to conserve power. In addition, a downlink assignment indicator (DAI) can be utilized to detect and indicate lost grants.