论文标题
无细胞系统的试点净化的试点分配超载
Overloaded Pilot Assignment with Pilot Decontamination for Cell-Free Systems
论文作者
论文摘要
必须解决无细胞大量多输入量输出（CF-MMIMO）中的试点污染，以适应大量用户。在以前的工作中，我们研究了一种称为子空间投影（SP）的净化方法。 SP通过使用用户通道子空间的主要组件的正交性将干扰与副驾驶用户分开。非载荷试点分配（PA），其中每个无线电单元（RU）没有为不同用户分配相同的飞行员，这限制了系统的光谱效率（SE），因为SP Channel估计能够与具有几乎正交子空间的共同驾驶用户打交道。在此限制的激励下，本文介绍了针对去污的超载PA方法，以改善CF系统的总和。数值模拟表明，在高用户密度方案下，超载PA方法比非载荷PA的SE更高。
The pilot contamination in cell-free massive multiple-input-multiple-output (CF-mMIMO) must be addressed for accommodating a large number of users. In previous works, we have investigated a decontamination method called subspace projection (SP). The SP separates interference from co-pilot users by using the orthogonality of the principal components of the users' channel subspaces. Non-overloaded pilot assignment (PA), where each radio unit (RU) does not assign the same pilot to different users, limits the spectral efficiency (SE) of the system, since SP channel estimation is able to deal with co-pilot users that have nearly orthogonal subspaces. Motivated by this limitation, this paper introduces overloaded PA methods adjusted for the decontamination in order to improve the sum SE of CF systems. Numerical simulations show that the overloaded PA methods give higher SE than that of non-overloaded PA at a high user density scenario.
