Semi-Orthogonal Multiple Access Sub-QAM Constellation Segmentation
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Solution Overview
Problem
Current radio frequency communications systems face challenges in efficiently managing interference and decoding complexity, especially in low signal-to-noise ratio environments, and require complex control signaling across multiple user equipment (UEs) in advanced multiple access techniques like NOMA.
Innovation Solution
The implementation of semi-orthogonal multiple access (SOMA) through power and modulation domain multiple access (PMDMA), which uses joint QAM constellation mapping and power offsets to simplify decoding and control signaling, allowing UEs with high-quality channels to decode signals without interference from low-quality channels, thereby reducing processing complexity and overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If NOMA combines power optimization and superposition coding to increase information transmission, then communication capacity is improved, but decoding complexity and control signaling overhead increase
Solution Approach 1:
The patent segments the QAM constellation into multiple sub-constellations, each assigned to different UEs. This segmentation allows each UE to decode only its assigned sub-constellation, significantly reducing decoding complexity while maintaining the superposition coding structure for increased communication capacity
Solution Approach 2:
Different sub-constellations are assigned different configurable weights locally, allowing each UE to have optimized signal characteristics tailored to its channel conditions. This local quality differentiation enables simpler decoding for each UE while maintaining overall system capacity
2Productivity
If NOMA uses power optimization per UE to improve data rates, then communication efficiency is improved, but control signaling complexity increases
Solution Approach 1:
The patent uses a universal control signaling format that serves multiple UEs simultaneously. The same signaling structure is used for all UEs regardless of their assigned sub-constellations, simplifying control signaling while maintaining per-UE power optimization through the configurable weights in the constellation design
3Productivity
If hierarchical modulation is used for rate adaptive scheduling to improve throughput, then communication efficiency is improved, but decoding requirements become more complex
Solution Approach 1:
The hierarchical modulation structure is segmented into distinct sub-constellations that can be independently decoded. Each UE decodes only its assigned sub-constellation, reducing the overall decoding complexity while maintaining the rate adaptive throughput benefits of hierarchical modulation
Data Source
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AI summary
A method for operating a transmitting device using semi-orthogonal multiple access (SOMA) includes determining power allocations and sub-quadrature amplitude modulation (sub-QAM) allocations for a first receiving device and a second receiving device in accordance with channel information associated with the first receiving device and the second receiving device, and transmitting information about a first power allocation for the first receiving device, and a first sub-QAM allocation for the first receiving device to the first receiving device.