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Joint Iterative Decoding Design of Cooperative Downlink SCMA Systems.
Hao Cheng1,2, Min Zhang1, Ruoyu Su1
1School of Internet of Things, Nanjing University of Posts and Telecommunications, Nanjing 210003, China.
Entropy (Basel, Switzerland)
|July 29, 2025
Summary
This study introduces a cooperative downlink Sparse Code Multiple Access (SCMA) system to enhance reliability for cell edge users. The proposed joint iterative decoding significantly improves performance over non-cooperative SCMA.
Area of Science:
- Wireless Communication
- Signal Processing
Background:
- Sparse Code Multiple Access (SCMA) offers high spectrum efficiency and massive connectivity for future networks.
- Cell edge users in SCMA systems face performance degradation due to signal attenuation.
Purpose of the Study:
- To propose a cooperative downlink SCMA system to enhance transmission reliability for cell edge users.
- To address the open issue of multiuser detection in cooperative downlink SCMA systems.
Main Methods:
- Development of a joint iterative decoding design utilizing a factor graph from direct and relay transmissions.
- Derivation of closed-form bit-error rate (BER) performance analysis.
Main Results:
- The proposed cooperative downlink SCMA system demonstrates superior performance compared to non-cooperative systems.
- The joint iterative decoding effectively manages multiuser detection challenges.
Conclusions:
- Cooperative strategies significantly enhance SCMA performance, particularly for users at the cell edge.
- The developed iterative decoding method provides a robust solution for cooperative SCMA networks.
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