Novel sparse regression LDPC (SR-LDPC) codes exhibit excellent performance over additive white Gaussian noise (AWGN) channels in part due to their natural provision of shaping gains. Though SR-LDPC-like codes have been considered within the context of single-user error correction and massive random access, they are yet to be examined as candidates for coordinated multi-user communication scenarios. This article explores this gap in the literature and demonstrates that SR-LDPC codes, when combined with coded demixing techniques, offer a new framework for efficient non-orthogonal multiple access (NOMA) in the context of coordinated multi-user communication channels. The ensuing communication scheme is referred to as MU-SR-LDPC coding. Empirical evidence suggests that, for a fixed SNR, MU-SR-LDPC coding can achieve a target bit error rate (BER) at a higher sum rate than orthogonal multiple access (OMA) techniques such as time division multiple access (TDMA) and frequency division multiple access (FDMA). Importantly, MU-SR-LDPC codes enable a pragmatic solution path for user-centric cell-free communication systems with (local) joint decoding. Results are supported by numerical simulations.

翻译：新型稀疏回归LDPC（SR-LDPC）码在加性高斯白噪声（AWGN）信道上展现出卓越性能，部分归因于其天然提供的成形增益。尽管类SR-LDPC码已在单用户纠错和大规模随机接入场景中得到研究，但其作为协调多用户通信候选方案的潜力尚未被探索。本文填补了这一文献空白，证明将SR-LDPC码与编码分离技术相结合，可为协调多用户通信信道中的高效非正交多址接入（NOMA）提供全新框架。由此产生的通信方案称为MU-SR-LDPC编码。实证结果表明，在固定信噪比（SNR）下，MU-SR-LDPC编码相比正交多址接入（OMA）技术（如时分多址接入（TDMA）和频分多址接入（FDMA）），能够以更高总速率实现目标误码率（BER）。更重要的是，MU-SR-LDPC码为采用（本地）联合解码的用户中心型无小区通信系统提供了一条实用化路径。数值仿真结果验证了上述结论的有效性。