Adaptive MCS and TBS Table Selection for 256QAM Data Transmission
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Solution Overview
Problem
In mobile communications systems, existing methods struggle to maximize frequency spectrum efficiency and system throughput due to challenges in adapting modulation and coding schemes to changing channel conditions, particularly when using 256QAM, and do not effectively utilize different user equipment attributes.
Innovation Solution
A base station selects one of multiple MCS and TBS tables based on user equipment attributes, including the inclusion of a 256-QAM modulation scheme, to determine the optimal modulation and coding settings for data transmission, thereby improving frequency spectrum efficiency and system throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a relatively high MCS level is used in a relatively bad channel state, then the throughput is improved, but the frame error rate becomes relatively high
Solution Approach 1:
The patent implements adaptive modulation and coding by dynamically selecting MCS levels based on real-time channel quality indicators (CQI). The base station adjusts the MCS level adaptively according to channel conditions, transitioning between different modulation and coding schemes to optimize both throughput and reliability under varying channel states.
Solution Approach 2:
The patent changes the MCS level parameter based on channel quality feedback. By monitoring CQI reports from user equipment and adjusting the MCS level accordingly, the system modifies transmission parameters (modulation order, coding rate) to achieve optimal performance for current channel conditions.
2Reliability
If a relatively low MCS level is used in a relatively good channel state, then the frame error rate is reduced, but the throughput is affected
Solution Approach 1:
The system dynamically adjusts MCS levels upward when channel conditions improve, as indicated by better CQI reports. This adaptive behavior ensures that the system exploits good channel conditions to achieve higher throughput while maintaining acceptable error rates, rather than operating with conservative fixed parameters.
Solution Approach 2:
The patent modifies transmission parameters by selecting higher MCS levels when channel quality is good. This parameter adjustment allows the system to increase spectral efficiency and throughput during favorable channel conditions while maintaining reliability through appropriate coding rates.
3Productivity
If 256QAM is used for PDSCH transmission, then the frequency spectrum efficiency is improved, but the control signaling complexity increases
Solution Approach 1:
The patent segments the MCS index space to accommodate 256QAM. By dividing the MCS table into different sections or using specific index ranges for 256QAM, the system enables high-order modulation while maintaining structured control signaling. This segmentation allows UEs to efficiently interpret MCS indices without requiring complete reconfiguration of the control signaling framework.
Solution Approach 2:
The patent extends the existing MCS indication mechanism to support multiple modulation schemes including 256QAM. By designing the MCS table and indication method to be universal across different modulation orders (QPSK, 16QAM, 64QAM, 256QAM), the system achieves high spectrum efficiency with 256QAM while reusing the same control signaling structure, thereby avoiding excessive complexity.
Data Source
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AI summary
Embodiments of the present invention provide a data transmission method, a base station and user equipment. The method includes: selecting one MCS table from at least two modulation coding scheme MCS tables to determine an MCS, and selecting one TBS table from at least two transport block size TBS tables to determine a TBS, where at least one MCS table of the at least two MCS tables includes an MCS corresponding to 256 quadrature amplitude modulation QAM; and sending service data to user equipment based on the determined MCS and the determined TBS. Frequency spectrum efficiency of the system can be maximized and a system throughput can be improved.