Railway cab signalling by track circuits and spread spectrum modulations

Track circuits are the traditional and perhaps the most important way to provide railway traffic control and train safety. However, electromagnetic interferences from solid state traction power applications and increased transmission capacity requirements are calling for new architecture and design. In this paper, spread spectrum modulations are considered, in order to provide interference rejection and multiple access capabilities. In particular, the possibility of providing track circuits suitable to work indifferently on networks equipped with different traction power systems is investigated