HARQ-ACK Feedback Scheduling Using Variable Bitmaps
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Solution Overview
Problem
In wireless communication networks, HARQ-ACK feedback resources are often inefficiently utilized, leading to unnecessary resource usage due to the fixed size of HARQ-ACK feedback messages, which do not adapt to the varying number of code blocks requiring retransmission.
Innovation Solution
The proposed solution involves using a bitmap in the second signal for scheduling retransmissions, where each bit indicates the decoding result of a code block group, allowing for flexible configuration of the bitmap length and splitting the modulation and coding scheme field to indicate both modulation and specific code block groups to be retransmitted, enabling efficient resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed size HARQ-ACK feedback messages are used, then the feedback structure is simple, but resource usage is inefficient and wasteful
Solution Approach 1:
The patent applies dynamics by making the feedback message size variable rather than fixed. The eMBB UE dynamically determines the number of CBGs to feedback based on the actual number of code blocks that need retransmission, allowing the feedback message length to adapt to different transmission scenarios and eliminate wasted resources on unnecessary feedback bits.
Solution Approach 2:
The patent changes the parameter of feedback message size from a fixed value to a variable value. By allowing the number of feedback bits to change based on the actual retransmission needs (number of NACKed CBGs), the system optimizes resource usage while maintaining feedback functionality.
2Device complexity
If fixed size HARQ-ACK feedback messages are used, then the feedback mechanism is simple, but retransmission efficiency is reduced due to unnecessary resource allocation
Solution Approach 1:
The patent segments the feedback process by dividing the code blocks into code block groups (CBGs) and providing feedback at the CBG level rather than treating all code blocks uniformly. This segmentation allows the system to identify and retransmit only the specific CBGs that failed, improving retransmission efficiency while maintaining manageable feedback complexity.
Solution Approach 2:
The patent applies partial action by feedback only the necessary information about CBGs that need retransmission, rather than providing complete feedback for all possible CBGs. This selective feedback approach reduces unnecessary resource allocation and improves efficiency by focusing resources only on problematic code block groups.
3Loss of energy
If the number of feedback bits is reduced to match actual retransmission needs, then resource usage improves, but the feedback structure becomes more complex
Solution Approach 1:
The patent makes the feedback structure universal by designing a single feedback mechanism that can handle different numbers of CBGs and retransmission scenarios. The same feedback procedure works whether 1 or N CBGs need retransmission, eliminating the need for multiple specialized feedback structures and actually reducing overall system complexity despite variable bit lengths.
Data Source
AI summary
Apparatuses, methods, and systems are disclosed for scheduling transmission of data. One apparatus (200) includes a receiver (212) that receives (402) a first signal from a base unit for scheduling a transmission of first data. The first data includes first multiple code blocks and each code block of the first multiple code blocks is independently decodable. The apparatus (200) includes a transmitter (210) that transmits (404) the first data. The receiver (212) receives (406) a second signal from the base unit for scheduling a transmission of second data, the second data includes second multiple code block groups of the first data, each code block group of the second multiple code block groups includes third multiple code blocks, and the transmitter (210) transmits (408) the second data.