Method and device for increasing the security against transmission errors in an information transmission system

US4138676A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Friedbert Becker · Lexington, US
• Wilhelm Grafinger · Munich, DE
• Bernhard Hildebrandt

Key dates

• Filing date: Mar 11, 1977
• Grant date: Feb 6, 1979
• Expiry date: Mar 11, 1997

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B61L25/045
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and device for increasing security with respect to transmission faults in an information-transmission system, particularly for the railroad field, in which an interrogation device and a passive response device are movable relative to one another, and the interrogation device transmits an interrogation signal, which can be periodically swept through a predetermined frequency band, preferably in the microwave range, and which during a read operation, receives during several periods from the passive response device, a frequency-selectively reflected interrogation signal, in accordance with a k-digit information item to be transmitted, which signal forms the response signal, with the response signals being suitably identified and one of a series thereof, preferably that with the least errors therein, being suitably through-connected for subsequent utilization, in which not only is the response signal with the fewest errors utilized, but of the signals having the same minimum number of errors, that response signal which had the highest input signal strength at the time of receipt of the interrogation device.