3D Constellation Mapping for Non-Orthogonal Multiple Access
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Solution Overview
Problem
Current non-orthogonal multiple access technologies, such as SCMA, PDMA, and MUSA, face limitations in supporting a large number of simultaneous wireless accesses due to coding gain loss and the need for distinct codebooks or sequences, which complicates standardization and reduces detection performance when terminals use identical or low-orthogonality reference signals.
Innovation Solution
A multiple access method involving channel coding, interleaving/scrambling, multidimensional constellation modulation, and grid mapping, where transmitters process bit sequences using different interleaver, scrambler, and constellation information, and receivers decode based on corresponding patterns to distinguish users, enabling more efficient simultaneous access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If non-orthogonal multiple access technologies (SCMA, PDMA, MUSA) are used to increase the number of simultaneous wireless accesses, then the capacity for simultaneous access is improved, but coding gain is lost and detection performance deteriorates when terminals use identical or low-orthogonality reference signals
Solution Approach 1:
The patent extends traditional 2D QAM constellations into 3D constellations by adding a power dimension. Each constellation point is represented as (I, Q, P) where P is the power level. This dimensional extension allows multiple users to be multiplexed in the power domain while maintaining orthogonal reference signals, thereby improving simultaneous access capacity without sacrificing detection performance
Solution Approach 2:
The patent changes the modulation parameter space from 2D (I, Q) to 3D (I, Q, P) by introducing power as an additional modulation dimension. This parameter expansion enables more users to share the same time-frequency resources through power-domain multiplexing while maintaining reference signal orthogonality for reliable detection
2Reliability
If distinct codebooks or sequences are used for different terminals to improve detection performance, then detection accuracy is improved, but standardization complexity increases
Solution Approach 1:
The patent introduces a universal 3D QAM constellation framework that can serve multiple users simultaneously. Instead of requiring user-specific codebooks, the system uses a common 3D constellation structure where users are distinguished by their power levels and resource allocations. This universal framework simplifies standardization while maintaining detection accuracy through the enhanced dimensional separation
3Reliability
If orthogonal time-frequency resources are allocated to users to maintain detection performance, then detection reliability is preserved, but the capacity for simultaneous access is limited
Solution Approach 1:
The patent adds the power dimension to traditional time-frequency resource allocation. Users can share the same time-frequency resources while being separated in the power domain through 3D constellation mapping. This enables non-orthogonal multiple access while maintaining detection reliability through the additional dimensional separation
Solution Approach 2:
The patent merges orthogonal reference signal structures with non-orthogonal data transmission in the power domain. Reference signals maintain orthogonality for reliable detection, while data transmissions utilize power-domain multiplexing to increase user capacity. This hybrid approach combines the advantages of both orthogonal and non-orthogonal schemes
Data Source
AI summary
A multiple access method, a multiple access transmitter, and a multiple access receiver includes performing, by a transmitter, channel coding on a bit sequence to determine a coded sequence. The method also includes interleaving and/or scrambling the coded sequence, and performing multidimensional constellation modulation on the interleaved and/or scrambled sequence; performing grid mapping on the modulated symbol sequence to determine a mapped sequence, and transmitting the mapped sequence. The method also includes receiving, by a receiver, mixed signals from multiple transmitters, the mixed signals are obtained by performing, by each of the multiple transmitters, interleaving and/or scrambling, multidimensional constellation modulation and grid mapping on data. The method further includes decoding, by the receiver, mixed information according to interleaver information and/or scrambler information, multidimensional constellation information and grid mapping pattern information corresponding to each transmitter to obtain data corresponding to each transmitter.