Intra-cluster Characteristics of 28 GHz Wireless Channel in Urban Micro   Street Canyon
  This paper investigates intra-cluster channel characteristics of non line-of-sight (NLOS) 28 GHz channels in street canyon scenarios. These channel characteristics include cluster numbers, number of subpaths within each cluster, intra-cluster delay spreads, and intra-cluster angular spreads. Both measurement and ray tracing results are presented and compared. Furthermore, distribution fittings are performed and models and parameters for different intra-cluster channel characteristics are proposed. 
Shangbin Wu, Sooyoung Hur, Kuyeon Whang, and Maziar Nekovee
cs.IT math.IT