Radio transmission path

摘要

In the wireless transmission of information between a receiving station in a track-bound vehicle and fixed-point transmitting stations, the problem arises of supplying the transmitting stations with power in an economical and reliable fashion. The method proposed here uses a signal transmitted from the mobile receiving station for supplying power to the fixed transmitting station and also the carrier signal, to which the information of the fixed transmitting station is added by modulation and which is then radiated back in the direction of the mobile receiving station. The signal transmitted from the mobile receiving station can be provided with auxiliary modulation in order to identify clearly the polling receiving station. If a band-spreading method is used for the auxiliary modulation, the immunity to interference of the transmission can be further increased.