The invention provides a method and apparatus for using a remote control device such as car key that generates unknown coded signal with other appliances, such as building's door, garage door or parking barriers, by demodulating and detecting time durations, sequence and other data pertaining the envelope of the unknown coded signal and storing the envelope data into a memory for comparing the stored envelope data with a data of an envelope of a newly received unknown coded signal and outputting match signal when the stored data and the newly received data match. The match signal can be used to operate locks, doors and barriers also in conjunction with systems including video interphone, alarm, emergency and access control system.