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.