Patent ID: 8902931

Claim:
A track circuit apparatus for a train, the track circuit apparatus comprising: a ground-based transmitter that is installed corresponding to each of a plurality of block sections divided from a track circuit formed by rails, digitally modulates transmission data at a carrier frequency predetermined and common for each of the block sections, and modulates by assigning different pseudo random noise (PN) codes to adjacent block sections and transmits the data; and a ground-based receiver or an on-train receiver that demodulates received data corresponding to a block section based on the carrier frequency of one of reception signals received from the block section and the PN code assigned to the block section, an interface of the ground-based transmitter, for signal connection to the track circuit of the block section corresponding to the ground-based transmitter per block section; and an interface of the ground-based receiver, for signal connection to the track circuit of the block section corresponding to the ground-based receiver per block section, wherein the interface of the ground-based transmitter or the interface of the ground-based receiver comprises an impedance matching circuit that matches the impedance of the track circuit to the impedance of the ground-based transmitter or ground-based receiver to facilitate transmission and reception.