AI 中文总结
本文针对采用软输出极化码的MIMO大规模无授权随机接入系统，设计基于ODMA的传输方案，提出分层模式检测与联合解码算法，兼顾多类增益并降低复杂度，仿真显示其鲁棒性强。
AI 中文摘要
本文研究采用软输出（SO）极化码的多输入多输出（MIMO）大规模无授权随机接入（URA）系统中，开关键控多址（ODMA）传输方案的设计。首先，在ODMA框架下引入一种三段式导频解耦编码方案，该方案在不增加传输开销的情况下降低了数据段的编码速率，提升了整体系统性能。基于该架构，开发了一种分层模式检测框架：先通过相关运算识别出传输模式的粗粒度候选集，在此基础上开发了一种基于消息传递（MP）的模式检测算法，迭代估计传输模式的后验概率，随后采用最大后验概率（MAP）估计以获得精确的模式检测结果。此外，研究了一种基于极化解码器逐位SO信息的联合模式检测与数据解码算法，利用极化解码器提供的后验概率信息优化模式检测，提升准确性。同时，借助连续消除列表极化解码器的逐位SO信息，开发了一种基于MP的迭代解码算法，显著增强解码性能。所提方案同时利用了解耦ODMA框架的传输增益、短块长体制下极化码的编码增益以及SO信息实现的迭代解码增益，且通过分层检测框架大幅降低了计算复杂度。仿真结果表明，所提方案具备强鲁棒性……
英文摘要
This paper investigates the design of the on-off division multiple access (ODMA) transmission scheme for multiple-input multiple-output (MIMO) massive unsourced random access (URA) systems with soft-output (SO) polar codes. First, a three-segment pilot-uncoupled coding scheme is introduced under the ODMA framework, which reduces the coding rate of the data segment without increasing the transmission overhead, improving the overall system performance. Building upon this architecture, a hierarchical pattern detection framework is developed. Specifically, a coarse-grained candidate set of transmission patterns is first identified through correlation operations. Based on this, a message-passing (MP)-based pattern detection algorithm is developed to iteratively estimate the posterior probabilities of transmission patterns, followed by the \textit{maximum a posteriori} (MAP) estimation to obtain the precise pattern detection result. Furthermore, a joint pattern detection and data decoding algorithm based on the bit-wise SO information of polar decoder is investigated, where the posterior probability information provided by the polar decoder is exploited to refine the pattern detection and contribute to an improved accuracy. In addition, by leveraging bit-wise SO information of the successive cancellation list polar decoder, an MP-based iterative decoding algorithm is developed to significantly enhance the decoding performance. The proposed scheme simultaneously exploits the transmission gain of uncoupled-ODMA framework, the coding gain of polar codes in the short-blocklength regime, and the iterative decoding gain enabled by SO information, while the computational complexity is significantly reduced through the hierarchical detection framework. Simulation results demonstrate that the proposed scheme achieves strong robustness ...
Comments15 pages, 9 figures, this paper has been accepted by the IEEE Transactions on Wireless Communications
