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A Low-Complexity Codebook Optimization Scheme for Sparse Code Multiple Access
DOI:10.1109/TCOMM.2022.3150416.png)
摘要
En 中文
Sparse code multiple access (SCMA) is a promising non-orthogonal multiple access technique to support massive connectivity for future wireless Internet of Things (IoT) networks. As the main feature of SCMA, modulation and spread spectrum is embedded into codebook mapping, offering significant codebook shaping gains to mitigate inter-cell interference. Maximizing the constellation-constrained average mutual information (AMI) is an effective way for SCMA codebook optimization. However, deriving a closed-form expression of the AMI is analytically intractable, while it is computationally costly to estimate the AMI by numerical methods. To address this challenge, this paper first derives a lower bound of the AMI with a closed-form expression. On this basis, we propose a novel codebook optimization method referred to as joint bare bones particle swarm optimization (JBBPSO) through maximizing the AMI lower bound. The proposed low-complexity method jointly optimizes the mother codebook including basic constellation and other non-zero-dimensional constellations, and the rotation angles of multiple users. Numerical results show that our proposed optimized codebooks outperform the state-of-the-art SCMA codebooks in terms of both the lower bound and the error performance.
Keyword:
Optimization
Wireless communication
NOMA
Codes
Closed-form solutions
Modulation
Downlink
Sparse code multiple access (SCMA)
codebook design
average mutual information (AMI)
lower bound
joint bare bones particle swarm optimization (JBBPSO)
期刊
IF:
8.3
论文数:
1.2W
被引数:
4.1W
机构
引用论文
An Uplink SCMA Codebook Design Combining Probabilistic Shaping and Geometric Shaping
IEEE ACCESS
IF3.6

