Multi-User Detection Based on Expectation Propagation for the Non-Coherent SIMO Multiple Access Channel
Multi-User Detection Based on Expectation Propagation for the Non-Coherent SIMO Multiple Access Channel
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DOI：
10.1109/twc.2020.3000419
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发表时间：
2020-09-01
影响因子：
10.4
通讯作者：
Schniter, Philip
中科院分区：
文献类型：
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作者：
Ngo, Khac-Hoang;Guillaud, Maxime;Schniter, Philip
研究了空间相关瑞利块衰落下具有一般信令的非相干单输入多输出(SIMO)多址接入信道。我们提出了一种新的软输出多用户检测器，它只使用关于信道分布的知识来计算每个传输信号的近似边缘后验。我们的检测器基于期望传播(EP)近似推理，在用户数、接收天线数和信道相干时间方面具有多项式复杂度。我们还提出了该检测器的两个简化方案，降低了复杂度。在Grassman信令的情况下，所提出的检测器的性能优于基于投影的干扰抑制的最先进的非相干检测器。在导频辅助信令的情况下，EP检测器在符号误码率方面优于一些传统的基于相干导频的检测器，包括球形译码和联合信道估计-数据检测方案。我们基于EP的检测器可产生真实后验的精确近似，从而获得高可实现的总和速率。当将这些检测器的软输出用于Turbo信道解码器时，根据误码率进一步观察这些检测器的增益。
We consider the non-coherent single-input multiple-output (SIMO) multiple access channel with general signaling under spatially correlated Rayleigh block fading. We propose a novel soft-output multi-user detector that computes an approximate marginal posterior of each transmitted signal using only the knowledge about the channel distribution. Our detector is based on expectation propagation (EP) approximate inference and has polynomial complexity in the number of users, number of receive antennas and channel coherence time. We also propose two simplifications of this detector with reduced complexity. With Grassmannian signaling, the proposed detectors outperform a state-of-the-art non-coherent detector with projection-based interference mitigation. With pilot-assisted signaling, the EP detector outperforms, in terms of symbol error rate, some conventional coherent pilot-based detectors, including a sphere decoder and a joint channel estimation-data detection scheme. Our EP-based detectors produce accurate approximates of the true posterior leading to high achievable sum-rates. The gains of these detectors are further observed in terms of the bit error rate when using their soft outputs for a turbo channel decoder.