Active presence signaling method for use in railroad marshalling site, involves superimposing voice signal and link assurance signal which is pseudo-sinusoidal signal obtained by filtering square signal using second order filter

摘要

The method involves superimposing a voice signal (6) and a link assurance signal (7) that is a pseudo-sinusoidal signal having a profile less sensitive to processing of a radio communication system. The pseudo-sinusoidal signal is obtained by filtering a square signal using a second order filter. The superimposed signal is transmitted from a mobile station (2) to a control station (3) of a driver (4).