NB-IoT MCS-to-TBS Mapping for 16 QAM Compatibility
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Solution Overview
Problem
The existing mapping relationship between MCS indexes and TBS indexes in NB-IoT does not support 16 QAM, affecting system performance, particularly in good channel conditions where TBS indexes with smaller values are underutilized.
Innovation Solution
A data transmission method that restricts the number of TBS indexes with smaller values and utilizes more TBS indexes with larger values in the mapping relationship between MCS indexes and TBS indexes, ensuring compatibility with 16 QAM and maintaining system performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing mapping relationship between MCS indexes and TBS indexes is used, then the system maintains backward compatibility with QPSK modulation, but it cannot support 16 QAM modulation which limits transmission rate improvement
Solution Approach 1:
The patent changes the mapping relationship parameters between MCS indexes and TBS indexes to support higher order modulation. Specifically, it redefines the mapping table to accommodate 16 QAM modulation by adjusting which TBS indexes are assigned to which MCS indexes, enabling the system to utilize higher transmission rates while maintaining compatibility with existing QPSK operations through selective mapping configuration
2Ease of operation
If more TBS indexes with smaller values are included in the mapping relationship, then the system maintains compatibility with existing protocols, but TBS indexes with larger values that could support 16 QAM are underutilized
Solution Approach 1:
The patent introduces dynamic selection capability where the system can adaptively choose between different mapping relationships based on channel conditions and modulation requirements. The mapping between MCS indexes and TBS indexes becomes dynamic rather than fixed, allowing the system to utilize TBS indexes with larger values when 16 QAM is employed, while still maintaining protocol compatibility through configurable mapping tables that can be selected based on operational context
3Productivity
If a new mapping relationship between MCS and TBS is defined to support 16 QAM, then transmission rate can be improved, but system complexity increases due to reconfiguration requirements
Solution Approach 1:
The patent designs a universal mapping framework that can accommodate both QPSK and 16 QAM modulation modes within a single configurable system. The same DCI structure and MCS field are used, but the mapping relationship between MCS indexes and TBS indexes can be reconfigured to support different modulation modes. This multi-functional approach allows the system to achieve higher transmission rates with 16 QAM while maintaining compatibility with existing QPSK operations, reducing the need for separate dedicated systems
Data Source
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AI summary
A data transmission method, a data transmission apparatus and a storage medium. The data transmission method comprises: acquiring a first parameter, wherein the first parameter is used for indicating a modulation and coding scheme (MCS) index; according to a mapping relationship table between the MCS index and a transport block size (TBS) index, determining the TBS index, wherein the mapping relationship table comprises a first number of TBS indexes, and the number of TBS indexes smaller than a preset TBS index value in the first number of TBS indexes is less than a second number thereof; and according to the determined TBS index, determining a TBS. By means of the present disclosure, a TBS index with a larger index value and an MCS index can be used for mapping during a data transmission process, so as to be compatible with a 16 QAM communication requirement and guarantee the system performance.