A novel handoff decision algorithm in TD-LTE based train-ground communication system
Communication Based Train Control (CBTC) system is a kind of advanced train automatic control system that integrates radio communication and automation control technology. Handoff happens frequently in CBTC train ground communication system, which may result in communication interrupt and long latency. In this paper, we propose a new handoff decision algorithm based on improved Grey Verhulst model for the Time Division-Long Term Evolution (TD-LTE) based train-ground communication system. The proposed handoff decision algorithm can be used under free space and leaky coaxial cable equipped environment. Improved Grey Verhulst model is used to predict the Reference Signal Receiving Power (RSRP) values from two Radio Remote Units (RRU). Compared with traditional Verhulst model, improved Grey Verhulst model can optimize parameters to eliminate the inherent errors in data sequence prediction. The handoff decision action is performed based on the predicted RSRP values. Simulation results show that the proposed handoff decision algorithm can decrease ping-pong handoff and improve the handoff delay compared with the traditional A3 event based scheme in LTE systems.