Data receiving system e.g. for motor vehicle locking system or immobiliser

摘要

The system has a receiver unit inside the vehicle which receives and demodulates a code signal modulated and transmitted by a portable code transmitter. A code detection unit measures the time between two pulses of the demodulated code signal at the start of the signal and within a period essentially shorter than the duration of the entire code signal. The measured interval is compared with desired values; if coincidence is detected with one desired value the entire code signal is passed for further processing. A comparison unit detects the coded information and compares it with a desired code. A control unit triggers a release signal if the codes agree.