The expectation propagation (EP) algorithm has received significant attention recently due to its good performance and manageable computational complexity for large-scale inference problems, such as detection for massive multiple-input multiple-output (MIMO) systems. Its computational complexity depends mainly on how messages are represented for computation and passing. In this letter, we propose a low-complexity EP algorithm based on location-aware and reliability-aware strategy, shortened as LR-EP, to efficiently implement the message computation and passing. At each iteration, only the most probable symbol candidates are selected to perform message computation based on a low-complexity quadrant detection and predetermined lookup table. In the iterative process, reliable variable nodes with sufficiently high posterior probabilities are kept intact, thus reducing the less efficient message passing. Numerical results illustrate that the proposed LR-EP receiver reduces computational complexity significantly compared to the conventional EP receiver with negligible performance degradation.

中文翻译：

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基于位置感知和可靠性感知策略的低复杂度 EP 接收器


期望传播（EP）算法由于其在大规模推理问题（例如大规模多输入多输出（MIMO）系统的检测）中具有良好的性能和可管理的计算复杂性，最近受到了极大的关注。其计算复杂度主要取决于消息如何表示以进行计算和传递。在这封信中，我们提出了一种基于位置感知和可靠性感知策略的低复杂度EP算法，简称LR-EP，以有效地实现消息计算和传递。在每次迭代中，仅选择最可能的候选符号来基于低复杂度象限检测和预定查找表来执行消息计算。在迭代过程中，具有足够高后验概率的可靠变量节点保持完整，从而减少了低效的消息传递。数值结果表明，与传统的 EP 接收器相比，所提出的 LR-EP 接收器显着降低了计算复杂度，并且性能下降可以忽略不计。