Pseudo N-Order Modulation for QAM-APSK Compatibility
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Solution Overview
Problem
Current constellation modulation schemes, such as QAM and APSK, are not compatible, leading to complex hardware design requirements due to differing transceiver structures, and existing APSK modulation is not adopted in standards like 5G, limiting compatibility and efficiency in high spectral efficiency and low PAPR scenarios.
Innovation Solution
An electronic device performs pseudo N-order first-type modulation on input bit sequences, where N symbols are part of M symbols from a second-type modulation, using bit-to-symbol mapping formulas or tables to simulate APSK from QAM, ensuring compatibility and reducing PAPR while maintaining high spectral efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If QAM modulation is used to achieve high spectral efficiency, then spectrum utilization is improved, but PAPR increases causing nonlinear distortion in high-power amplifiers
Solution Approach 1:
The patent extracts a subset of constellation points from the QAM modulation scheme to create a new modulation format. Specifically, it selects only those QAM constellation points that lie on circles with radii corresponding to APSK modulation, thereby extracting the low-PAPR property from the QAM scheme while maintaining high spectral efficiency through the remaining dense constellation structure.
Solution Approach 2:
The patent applies local quality by creating different regions in the constellation diagram with different properties. The selected constellation points form circular patterns (APSK-like) that provide low PAPR characteristics, while the overall dense packing maintains high spectral efficiency. This local structural optimization resolves the contradiction between global spectral efficiency and local PAPR control.
2Object-generated harmful factors
If APSK modulation is used to reduce PAPR, then nonlinear distortion is reduced, but compatibility with high spectral efficiency schemes like QAM decreases
Solution Approach 1:
The patent creates a universal modulation scheme that serves multiple functions: it maintains compatibility with existing QAM systems by using a subset of QAM constellation points, provides low PAPR characteristics like APSK for reduced nonlinear distortion, and enables flexible adaptation between different spectral efficiency requirements. This multi-functional approach resolves the compatibility issue.
Solution Approach 2:
The patent embeds APSK-like circular constellation structures within the larger QAM constellation framework. The selected constellation points form nested circular patterns that preserve the low-PAPR property, while these nested structures are contained within the overall QAM grid, maintaining compatibility with QAM-based systems and enabling seamless integration.
3Reliability
If different transceiver structures are designed for different modulation methods, then modulation performance is optimized, but hardware complexity increases
Solution Approach 1:
The patent designs a universal transceiver structure that can handle both QAM and the new hybrid modulation scheme using the same hardware components. By formulating the modulation as a subset selection from QAM constellation points, the system uses a single set of modulators, demodulators, and signal processing units, eliminating the need for separate hardware chains and reducing overall system complexity.
Solution Approach 2:
The patent achieves different modulation performances through parameter changes rather than structural changes. By adjusting which QAM constellation points are selected and how they are mapped to symbols, the system can adapt between different spectral efficiency modes and PAPR requirements using the same hardware, thereby optimizing performance without increasing hardware complexity.
Data Source
AI summary
The present disclosure provides an electronic device and a modulation method. The electronic device includes: a receiving unit, which is configured to obtain a first input bit sequence; and a control unit, which is configured to perform pseudo N-order first type modulation on the first input bit sequence, wherein N first symbols that may be obtained by means of the pseudo N-order first type modulation are a portion of second symbols that may be obtained by means of M-order second type modulation, M and N are positive integers, and M is greater than N.