Uplink Waveform Selection for 5G Terminal Devices
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Solution Overview
Problem
Current wireless communications systems face challenges in selecting the appropriate waveform for terminal devices to optimize performance, particularly in fifth-generation systems supporting both CP-OFDM and DFT-S-OFDM waveforms, which affects signal-to-noise ratio and throughput.
Innovation Solution
A network side device measures signal-to-noise ratios for terminal devices using multiple RANKs, calculates modulation and coding efficiencies, and selects a target waveform type (CP-OFDM or DFT-S-OFDM) based on historical waveforms and RANKs, optimizing modulation and coding schemes to improve uplink throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed waveform (CP-OFDM) is used for all terminal devices, then the system implementation is simple, but the uplink throughput and signal-to-noise ratio performance deteriorate
Solution Approach 1:
The patent implements dynamic waveform selection where the base station determines the appropriate waveform (CP-OFDM or DFT-S-OFDM) for each terminal device based on real-time channel conditions, RANK values, and signal-to-noise ratios. This dynamic adaptation resolves the contradiction by allowing the system to switch between fixed simplicity and optimized performance based on operational requirements.
Solution Approach 2:
The patent changes the waveform parameter based on multiple factors including RANK values (1 or 2), signal-to-noise ratio thresholds, and historical waveform selections. By adjusting this critical parameter dynamically, the system achieves both implementation simplicity through standardized selection criteria and improved throughput through condition-based optimization.
2Productivity
If waveform selection is optimized for each terminal device, then uplink throughput and signal-to-noise ratio improve, but the system complexity and calculation overhead increase
Solution Approach 1:
The patent employs preliminary action by pre-establishing selection criteria and thresholds for waveform determination. The base station uses pre-defined rules based on RANK values, signal-to-noise ratio comparisons, and historical waveform data to make rapid decisions without complex real-time calculations, thus improving throughput while controlling complexity.
Solution Approach 2:
The patent implements feedback mechanisms where the base station monitors terminal device performance, channel conditions, and waveform selection outcomes. This feedback loop allows the system to refine waveform selections based on actual performance data, achieving improved throughput through iterative optimization while maintaining manageable complexity through learned patterns.
3Measurement precision
If multiple RANKs are measured and modulation and coding efficiency is calculated for each, then waveform selection accuracy improves, but the calculation overhead and processing time increase
Solution Approach 1:
The patent applies partial action by measuring signal-to-noise ratios for multiple RANKs (typically 1 and 2) and calculating modulation and coding efficiency selectively based on the measurement results. Rather than exhaustive analysis of all possible parameters, the system performs targeted measurements and calculations only when they directly impact the waveform selection decision, thus improving accuracy while minimizing time loss.
Data Source
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AI summary
A waveform selection method and a device are disclosed. The method includes: obtaining an uplink signal sent by a terminal device; measuring, based on the obtained uplink signal sent by the terminal device, N corresponding first signal-to-noise ratios when the terminal device sends the uplink signal by using N RANKs; calculating a first modulation and coding efficiency corresponding to each first signal-to-noise ratio; calculating, based on the first modulation and coding efficiency corresponding to each first signal-to-noise ratio, a second modulation and coding efficiency corresponding to each RANK; selecting a target modulation and coding efficiency from second modulation and coding efficiencies corresponding to the N RANKs; determining a target modulation and coding scheme based on the target modulation and coding efficiency and a historical waveform; determining a target modulation scheme based on a target RANK and the target modulation and coding scheme; and determining, based on the target modulation scheme and the RANK, a waveform type currently selected for the terminal device, where the waveform type includes CP-OFDM or DFT-S-OFDM. A proper waveform can be selected for the terminal device by using this solution, thereby improving a spectrum utilization rate.