Terminal Device Rate Matching via Layer Capability Signaling
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Solution Overview
Problem
In LTE radio systems, there is a mismatch between the actual and assumed operations of base station and terminal devices regarding bit width of Rank Indicator (RI), rate matching of code blocks, and soft channel bit storage, leading to potential communication failures.
Innovation Solution
A terminal device is designed to transmit capability information including maximum numbers of layers supported for Hybrid Automatic Repeat reQuest (HARQ) processing, allowing for appropriate rate matching of code blocks based on configured transmission modes and information received from the base station, ensuring accurate communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the terminal device transmits only a single UE category indicating maximum HARQ buffer size, then the signaling overhead is reduced, but the base station cannot accurately determine the appropriate rate matching configuration for different transmission modes
Solution Approach 1:
The patent segments the UE category information into two separate indicators: first UE category information indicating the maximum number of soft channel bits for HARQ processing, and second UE category information indicating the maximum number of layers supported. This segmentation allows the base station to independently determine rate matching configuration based on the first UE category while the terminal determines RI bit width based on the second UE category, resolving the contradiction between reduced signaling and improved adaptability.
2Device complexity
If the terminal device assumes a fixed maximum number of layers for RI bit width determination, then the terminal processing is simplified, but the RI bit width may not match the actual layers used in different transmission modes causing communication failures
Solution Approach 1:
The patent introduces dynamic adaptability by providing the second UE category information that indicates the maximum number of layers supported by the terminal. This allows the RI bit width to be dynamically adjusted according to the actual transmission mode and number of layers being used, rather than assuming a fixed maximum. The base station uses this information to correctly interpret the RI feedback, ensuring communication reliability while keeping terminal processing manageable through standardized determination rules.
3Manufacturing precision
If the base station configures rate matching based on the terminal's actual capabilities, then data transmission accuracy is improved, but the terminal must provide detailed capability information increasing signaling overhead
Solution Approach 1:
The patent extracts the essential capability information needed for rate matching into a separate first UE category indicator that specifies the maximum number of soft channel bits for HARQ processing. This extracted information is sufficient for the base station to determine the appropriate rate matching configuration without requiring the terminal to report all possible capability parameters, thus improving data transmission accuracy while minimizing signaling overhead.
Data Source
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AI summary
A terminal device decodes a code block of a transport block, and in a case that a first transmission mode is configured, a rate matching for the code block is processed based on a first total number of soft channel bits; in a case that a second transmission mode is configured and first information is configured, a rate matching for the code block is processed based on the first total number of soft channel bits; and in a case that the second transmission mode is configured and the first information is not configured, a rate matching for the code block is processed based on a second total number of soft channel bits. Here, the first information indicates the maximum number of layers associated with PDSCH transmission.