Abstract: A method for surveillance of a railroad track includes equipping rail vehicles which run on the railroad track with a recording unit which takes images of the railroad track or the surroundings thereof. The images are saved and automatically processed or analyzed for specific incidents by using image detection procedures. If such an incident is detected, an action can be executed, an alarm triggered or a police investigation initiated. At the same time, it is advantageous that a flexible surveillance of the railroad track and effective procedures to prevent theft and damage along the railroad track can be achieved by using inexpensive resources. The images can also be transmitted to a central location and monitored there (e.g. continuously) by operators. A rail vehicle, an apparatus for surveillance of a railroad track and a system having a rail vehicle and a central unit are also provided.

Abstract: The orthogonal frequency division multiplexing (OFDM) method is well-known for transmitting data on electrical power supply lines. According to this method, the items of information to be transmitted are distributed among numerous carriers, and the composite signal of the modulated carrier signals is transmitted in the form of an OFDM block. Standard OFDM methods are, however, highly sensitive to strong periodic pulse jammers. According to the invention, the method is thus devised such that the OFDM blocks to be transmitted have a length of approximately 85% of the interval between two periodic disturbing pulses. The carrier interval accordingly results from the reciprocal duration of the OFDM blocks. The transmitted OFDM blocks are synchronized with pulse-shaped periodic jammers in such a manner that one block at a time is located between two disturbing pulses. The pulse-shaped jammers can be gated at the receiver.

Abstract: The orthogonal frequency division multiplexing (OFDM) method is well-known for transmitting data on electrical power supply lines. According to this method, the items of information to be transmitted are distributed among numerous carriers, and the composite signal of the modulated carrier signals is transmitted in the form of an OFDM block. Standard OFDM methods are, however, highly sensitive to strong periodic pulse jammers. According to the invention, the method is thus devised such that the OFDM blocks to be transmitted have a length of approximately 85% of the interval between two periodic disturbing pulses. The carrier interval accordingly results from the reciprocal duration of the OFDM blocks. The transmitted OFDM blocks are synchronized with pulse-shaped periodic jammers in such a manner that one block at a time is located between two disturbing pulses. The pulse-shaped jammers can be gated at the receiver.