Improvement of the Cluster-Level Spatial Consistency of Channel Simulator With Reference Points Transition Method

Abstract

Spatial consistency is a basic physical characteristic of the wireless channel because the neighboring spatial positions share similar clusters, resulting in the spatial correlations of both large-scale parameters (LSPs) and small-scale parameters (SSPs). Although the existing geometry-based stochastic channel model (GSCM)-based channel simulator try to realize the spatial consistency of the channel parameters by the correlated map method or the sum-of-sinusoids (SOS) method, such a stochastic approach also results in that the change of cluster positions calculated by the SSPs appears considerable even in closely neighboring spatial positions, which violates the wide-sense stationary (WSS) conditions over a short distance. To further improve the cluster-level spatial consistency, we investigate the pattern of change of the root mean square (RMS)-delay spread (DS) and derive the continuity of RMS-DS in the entire space. Taking the continuity of RMS-DS as the optimization goal, we determine the change of clusters of the channel, i.e., cluster appearance and disappearance, when the spatial position of mobile terminal (MT) changes and propose the reference points (RPs) transition method. Specifically, we firstly choose the RPs in the target area according to the correlation distance, then generate the channels of RPs by the SOS method stochastically, and finally obtain the channel of MT through the transitions between the RPs deterministically. Simulation results demonstrate that the channel simulator with the proposed RPs transition method can achieve the spatial consistency of LSPs, SSPs, and clusters in the entire 2D or 3D space.