MCS Table Selection for DFT-s-OFDM Uplink Capacity
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Solution Overview
Problem
In 5G new radio (NR) communication, the existing DFT-s-OFDM waveform supports only single-layer transmission, which limits uplink capacity when using an existing MCS table for physical uplink shared channels (PUSCH), affecting demodulation thresholds and transmission reliability.
Innovation Solution
A method to determine an MCS table with the same spectral efficiency but a lower coding rate based on the number of transmission layers, using information from network devices to select an appropriate MCS table, such as the first, second, or third MCS table, to reduce demodulation thresholds and increase uplink capacity for DFT-s-OFDM waveform in PUSCH transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an existing MCS table is used for DFT-s-OFDM waveform transmission, then the transmission structure is simple, but the uplink capacity is limited and demodulation threshold is high
Solution Approach 1:
The patent changes the parameters of the MCS table by introducing a new table specifically designed for DFT-s-OFDM waveform with multi-layer transmission. This new MCS table adjusts the mapping relationship between MCS indices and modulation/coding parameters, enabling lower demodulation thresholds while maintaining spectral efficiency, thus resolving the contradiction between uplink capacity and reliability
Solution Approach 2:
The patent segments the MCS table into different versions: one for single-layer transmission and another for multi-layer transmission. By segmenting the transmission scenarios and providing dedicated MCS tables for each, the system can optimize parameters specifically for DFT-s-OFDM multi-layer transmission, improving both capacity and reliability without affecting other transmission modes
2Productivity
If DFT-s-OFDM waveform supports multi-layer transmission, then uplink capacity increases, but demodulation threshold increases and reliability decreases
Solution Approach 1:
The patent introduces parameter adjustments in the MCS table specifically for multi-layer DFT-s-OFDM transmission. By modifying the coding rate and modulation order mappings in the MCS table, the system achieves lower demodulation thresholds even when supporting multi-layer transmission, thus maintaining reliability while improving capacity
Solution Approach 2:
The patent creates a copied and adapted version of the MCS table tailored for DFT-s-OFDM waveform. This copied table inherits the structure of existing MCS tables but is customized with adjusted parameters suitable for DFT-s-OFDM characteristics, enabling multi-layer transmission with improved reliability
Data Source
AI summary
Embodiments of this application disclose a method and an apparatus for determining a modulation and coding scheme MCS table. The method includes: When a discrete fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM waveform is used for transmission of a physical uplink shared channel PUSCH, a terminal device receives first information from a network device, where the first information indicates a quantity of transmission layers of the PUSCH; and determines, based on the first information, an MCS table used for transmission of the PUSCH. According to embodiments of this application, a demodulation threshold for uplink transmission of a PUSCH is reduced, reliability of transmission of the PUSCH is improved, and an uplink capacity is increased.