A Scatterer Localization Method Using Large-Scale Antenna Array Systems

As ultra-massive multiple-input multiple-output (UM-MIMO) has emerged as a key technology for millimeter-wave and terahertz communications, the spherical wave propagation should be considered for channel modeling. Therefore, it is critical to identify the locations and evolving behaviors of scatterers, i.e., the sources of the spherical wavefronts. In this contribution, a novel space-alternating generalized expectation-maximization (SAGE) based scatterer localization algorithm is proposed, where a large-scale antenna array is divided into multiple sub-arrays. Due to the decreased aperture of each sub-array, plane wave assumption can be applied to estimate the angles of departure/arrival, delays and amplitudes of multipath components (MPCs). Based on the angle variations of MPCs observed at different sub-arrays, the corresponding scatterers can be located. The proposed algorithm is verified in a simulation using a large-scale uniform circular array (UCA) system. Moreover, we apply this algorithm to an indoor measurement campaign conducted at 27-29\,GHz in a hall scenario. Dominant scatterers are identified, which can be used for the development of further geometry-based stochastic channel models

Geometry-Based Clustering Characteristics for Outdoor Measurements at 28-30 GHz

This paper presents an analysis of channel characteristics for an outdoor scenario at the frequency band of 28-30 GHz. A geometry-based clustering algorithm is proposed to group the measured multipath components (MPCs) based on the interaction points on the surrounding walls or objects obtained from Ray Tracing 3-D simulations, which is more physically interpretable than the traditional clustering algorithm. The cluster-level characteristics at a total of 15 positions along a pre-defined route covering both line-of-sight (LoS) and non-LoS (NLoS) scenarios are investigated. Moreover, power contributions of MPCs with multiple bounces (up to 7 bounces in NLoS condition) from the interaction objects (IOs) are also investigated