EP 0515860 A3 19930818 - APPARATUS AND METHOD OF ELECTRONIC DUPLICATION PREVENTION OF REMOTE ENTRY SIGNAL
Title (en)
APPARATUS AND METHOD OF ELECTRONIC DUPLICATION PREVENTION OF REMOTE ENTRY SIGNAL
Publication
Application
Priority
US 70586991 A 19910526
Abstract (en)
[origin: EP0515860A2] A remote entry device for enabling vehicle access which utilizes a friend/foe screening technique comprising an initial sequence of four paired pulses transmitted sequentially. Each pair is transmitted at respectively larger amplitudes which have been selected as appropriate for communication at a corresponding distance of transmission. Upon receipt, the receiver amplifies the pulses and effects a screening process which is a result of the band pass properties of the preamplifier. The output of the preamplifier is then supplied to a microprocessor as pairs of signals which are compared to a reference pair. Once an appropriate pulse pair is received, a window is opened and the specific vehicle code may be transmitted and correspondingly received in serial fashion. Upon receipt of an appropriate friend/foe signal and I.D. code, the central locking command may be actuated to implement the intended command. <IMAGE>
IPC 1-7
IPC 8 full level
G01S 7/48 (2006.01); G01S 17/74 (2006.01); G07C 9/00 (2006.01)
CPC (source: EP)
G07C 9/00182 (2013.01); G07C 2009/00785 (2013.01)
Citation (search report)
- [A] EP 0017448 A1 19801015 - WALTON CHARLES A
- [A] GB 2196203 A 19880420 - APT CONTROLS LTD
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
EP 0515860 A2 19921202; EP 0515860 A3 19930818; JP H05196734 A 19930806
DOCDB simple family (application)
EP 92107365 A 19920430; JP 13351092 A 19920526