Anti-theft protection system for a motor vehicle

摘要

In a portable transmitter, an item of code information is modulated with each of two different carrier frequencies. In a receiver, a single item of code information is demodulated by logic operation from all of the code signals which are received. If the item of code information agrees with an expected item of desired code information, a release signal is produced. As a result of the separate transmission in two different transmitting channels, the item of code information is transmitted redundantly, as a result of which the item of code information is still reliably received even if there is disturbance of a transmitting channel.