论文标题
部分可观测时空混沌系统的无模型预测
Multidimensional orthogonal matching pursuit: theory and application to high accuracy joint localization and communication at mmWave
论文作者
论文摘要
通常,贪婪的方法,尤其是正交匹配的追求,是广泛应用中最常用的稀疏恢复技术。这些方法的复杂性高度依赖于所选的字典大小以表示稀疏信号。当词典必须很大才能实现高精度重建时,贪婪的策略可能会导致过于良好的复杂性。在本文中,我们首先提出了一种新型的稀疏恢复问题的制定,其中稀疏信号由一组独立和较小的词典代表而不是大型单个字典表示。然后,我们通过多维词典得出了低复杂性多维正交匹配追踪(MOMP)策略。投影步骤是在字典的每个维度上迭代执行的,同时固定所有其他维度以在合理的复杂性下实现高精度估计。最后,我们提出了高分辨率时域通道在毫米波(MMWave)频率上的问题,作为可以用MOMP解决的多维稀疏恢复问题。后来,将通道估计值转换为高精度用户位置估计,利用了一种利用室内通道的特定几何形状的新定位算法。模拟结果表明,在现实的3D场景中运行时,MOMP在毫米波频率下高精度定位的有效性,而实用的MIMO架构可在MMWave上可行,并且不采取完美的同步假设来简化问题。
Greedy approaches in general, and orthogonal matching pursuit in particular, are the most commonly used sparse recovery techniques in a wide range of applications. The complexity of these approaches is highly dependent on the size of the dictionary chosen to represent the sparse signal. When the dictionary has to be large to enable high accuracy reconstructions, greedy strategies might however incur in prohibitive complexity. In this paper, we propose first the formulation of a new type of sparse recovery problems where the sparse signal is represented by a set of independent and smaller dictionaries instead of a large single one. Then, we derive a low complexity multdimensional orthogonal matching pursuit (MOMP) strategy for sparse recovery with a multdimensional dictionary. The projection step is performed iteratively on every dimension of the dictionary while fixing all other dimensions to achieve high accuracy estimation at a reasonable complexity. Finally, we formulate the problem of high resolution time domain channel estimation at millimeter wave (mmWave) frequencies as a multidimensional sparse recovery problem that can be solved with MOMP. The channel estimates are later transformed into high accuracy user position estimates exploiting a new localization algorithm that leverages the particular geometry of indoor channels. Simulation results show the effectiveness of MOMP for high accuracy localization at millimeter wave frequencies when operating in realistic 3D scenarios, with practical MIMO architectures feasible at mmWave, and without resorting to perfect synchronization assumptions that simplify the problem.