Empirical Geometry-Based Random-Cluster Model for High-Speed-Train Channels in UMTS Networks

Abstract

In this paper, a recently conducted measurement campaign for high-speed-train (HST) channels is introduced, where the downlink signals of an in-service Universal Mobile Terrestrial System (UMTS) deployed along an HST railway between Beijing and Shanghai were acquired. The channel impulse responses (CIRs) are extracted from the data received in the common pilot channels (CPICHs). Within 1318 km, 144 base stations (BSs) were detected. Multipath components (MPCs) estimated from the CIRs are clustered and associated across the time slots. The results show that, limited by the sounding bandwidth of 3.84 MHz, most of the channels contain a single line-of-sight (LoS) cluster, and the rest consists of several LoS clusters due to distributed antennas, leaking cable, or neighboring BSs sharing the same CPICH. A new geometry-based random-cluster model is established for the clusters' behavior in delay and Doppler domains. Different from conventional models, the time-evolving behaviors of clusters are characterized by random geometrical parameters, i.e., the relative position of BS to railway, and the train speed. The distributions of these parameters, and the per-cluster path loss, shadowing, delay, and Doppler spreads, are extracted from the measurement data. Index Terms-Geometry-based stochastic model, high speed train, random cluster model, time-variant channel, Universal Mobile Terrestrial System.

Channel Measurements and Models for High-Speed Train Communication Systems: A Survey

“…Correspondingly, all of the aforementioned measurements were for narrowband channels with bandwidth of 200 kHz. Wideband channel measurements with higher bandwidths, i.e., 10-100 MHz, and higher carrier frequencies, i.e., 2.1-5.2 GHz, were reported in [42], [44]- [47], [62], [63], [73]- [75], [78], [89]- [91].…”

A Simplified Multipath Component Modeling Approach for High-Speed Train Channel Based on Ray Tracing

“…The channel model is based on the channel spreading function [37]. At time , the channel spreading function is expressed as the superposition of ( ) paths…”

“…However, due to oversimplified propagation environment the parametrization work from measurements would be hard [36]. In [37] the GSCM with random-cluster is proposed in delay and Doppler domains at 2.14 GHz. And yet for the limited bandwidth, multipath components (MPCs) are unresolvable and only a LoS cluster is modeled according to LoS geometry.…”

Comparative Study of Least Square Methods for Tuning Erceg Pathloss Model

“…In most published literatures, the least square error optimization approach is mostly used [17][18][19][20][21]. There are different approaches to implement the least square optimization of pathloss model.…”