Continuous Phase Modulation for Non-Linear Power Amplifier Resilience
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Solution Overview
Problem
Current wireless communication systems, particularly in 5G NR, face challenges in achieving high bandwidth and energy efficiency, especially in millimeter wave scenarios with non-linear power amplifiers.
Innovation Solution
The implementation of continuous phase modulation (CPM), constrained envelope CPM (ceCPM), and multi-amplitude CPM (MACPM) with DFT precoding, allowing for flexible waveform configuration based on communication conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional modulation schemes (QAM, APSK) are used in 5G NR, then spectral efficiency is improved, but resistance to non-linear power amplifiers deteriorates
Solution Approach 1:
The patent changes the modulation parameters by introducing continuous phase modulation (CPM) with constant envelope properties. This modifies the signal characteristics to be more resilient to non-linear power amplifier distortion while maintaining spectral efficiency through optimized phase transitions and modulation indexing.
Solution Approach 2:
The patent combines multiple modulation techniques (CPM, ceCPM, MACPM) with DFT precoding to create a composite modulation scheme. This hybrid approach integrates the constant envelope benefits of CPM with the spectral efficiency of DFT-s-OFDM, achieving both high spectral efficiency and resistance to non-linear amplification.
2Adaptability or versatility
If DFT precoding is applied to enhance user multiplexing, then user multiplexing capability is improved, but device complexity increases
Solution Approach 1:
The patent segments the modulation process into distinct stages: DFT precoding stage, modulation stage, and transmission stage. By separating these functions, the system can apply user-specific DFT precoding matrices for multiplexing while keeping the actual modulation operation relatively simple, thus managing device complexity through functional decomposition.
Solution Approach 2:
The patent implements a universal DFT precoding framework that serves multiple users simultaneously with different modulation schemes (QAM, APSK, CPM). The same DFT-based precoding structure handles user multiplexing, resource allocation, and modulation scheme selection, reducing overall system complexity through multi-functionality.
3Adaptability or versatility
If flexible waveform configuration is implemented, then adaptability to communication conditions is improved, but system complexity increases
Solution Approach 1:
The patent introduces dynamic waveform configuration where the modulation scheme (QAM, APSK, CPM, ceCPM, MACPM) and DFT precoding parameters can be adaptively changed based on communication conditions such as channel quality, user mobility, and interference levels. This dynamic adaptation allows the system to optimize performance for different scenarios without requiring completely separate systems for each condition.
Data Source
AI summary
Aspects presented herein may improve communications at high bandwidth or coverage limited scenarios, which may specify high transceiver energy efficiency and robustness to non-linear power amplifiers. In one aspect, a first network node transmits first information indicative of at least one of a modulation scheme or a modulation parameter to a second network node, where the modulation scheme is from a set of modulation schemes and the modulation parameter is associated with the modulation scheme, and where the set of modulation schemes includes one or more of: APSK, QAM, CPM, ceCPM, or MACPM. The first network node, from the second network node, second information indicative of at least one of the modulation scheme or the modulation parameter associated with the modulation scheme for at least one transmission.