Investigation of MIMO Channel Characteristics in Tunnel at 1.4725 and 6 GHz

Abstract

In recent years, high-speed railway and subway are being built rapidly in China. Tunnel scenario is a major scenario in some of the high-speed railways and most of the subways. Channel characteristic is the decisive condition of wireless communication system design in tunnel. The availability of multiple-input multiple-output (MIMO) in tunnel is an important issue in the next generation communication network. This paper presents results from a wideband measurement campaign at center frequency of 1.4725 and 6 GHz in a tunnel laboratory. The path loss, root-mean-square delay spread (RMS-DS) characteristics by single-input single-output (SISO) measurement and the angle spread, channel matrix singular values, and MIMO capacity at various link distances by MIMO measurement are illustrated. and these provide insights for MIMO system deployment. And also, the threshold of singular value for channel matrix rank reduction is given.