LTE Performance over High Speed Railway Channel

Global System for Mobile Communications Railways (GSM-R) has been the de facto standard for wireless communications in the field of High Speed Railway (HSR). However due to the increasing requirements associated with HSR, Long Term Evolution for Railways (LTE-R) has been presented as the following wireless communication system. In this paper a complete performance analysis of LTE for HSR is carried out giving results for both Physical (PHY) and Medium Access Control (MAC) layer in order to identify appropriate Quality of Service (QoS) requirements. An adequate Rician channel model with a time-varying Doppler frequency offset has been integrated in a Downlink LTE simulator using Wireless Mobile SIMulator (WM-SIM) platform. The effect of Inter-Carrier Interference (ICI) degrades the Bit Error Rate (BER) whereas the reduced coherence time makes obsolete channel state information reducing the performance of adaptive modulation and coding (AMC). For this reason open loop Multiple Input Multiple Output (MIMO) techniques are attractive. Results illustrate the benefits of LTE in HSR scenario.