Secure remote control system
First Claim
1. A method of providing security for a remote control system which includes a transmitter and a receiver, comprising the steps of:
- generating an electromagnetic radiation signal with the transmitter, the signal including a plurality of pulse pairs, each pair including a start pulse and a stop pulse, with the time interval between each start-and-stop pulse being proportional to a corresponding value in a predetermined key code sequence;
detecting the electromagnetic signal with the receiver;
deriving the key code sequence from the time intervals in the received sequence of start-and-stop pulse pairs;
comparing the derived key code sequence to a predetermined lock code sequence; and
generating a valid signal if each value in the derived key code sequence corresponds in a predetermined manner to each value in the lock code sequence by generating a valid signal if each value in the derived key code sequence is the complement of the corresponding value in the lock code sequence.
4 Assignments
0 Petitions
Accused Products
Abstract
A vehicle access transmitter and receiver pair which cooperate to implement a code transmission strategy which requires a minimum amount of energy thereby accomplishing maximum battery life while achieving operations secure from unauthorized access. The transmitter produces a string of start-and-stop pulse pairs which are each spaced in a timed interval so as to represent unique values. In operation the transmitter generates a sequence of four start-and-stop pulses with the duration of start-and-stop pulse pair proportional to the respective key code. The receiver detects the pulses and supplies them to a code comparison circuit. A lock code is stored and supplied to the code comparison circuit. During the reception time between each start-and-stop pulse in a pair, the demodulator counts up sequentially producing a vector sum of the lock code and the received code value. If the vector sum of all code valves stored and received equals zero, then a VALID signal is generated by the code comparison circuit permitting access to the vehicle via the selected path, i.e., Door, Trunk, etc.
15 Citations
10 Claims
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1. A method of providing security for a remote control system which includes a transmitter and a receiver, comprising the steps of:
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generating an electromagnetic radiation signal with the transmitter, the signal including a plurality of pulse pairs, each pair including a start pulse and a stop pulse, with the time interval between each start-and-stop pulse being proportional to a corresponding value in a predetermined key code sequence; detecting the electromagnetic signal with the receiver; deriving the key code sequence from the time intervals in the received sequence of start-and-stop pulse pairs; comparing the derived key code sequence to a predetermined lock code sequence; and generating a valid signal if each value in the derived key code sequence corresponds in a predetermined manner to each value in the lock code sequence by generating a valid signal if each value in the derived key code sequence is the complement of the corresponding value in the lock code sequence. - View Dependent Claims (2, 3, 4)
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5. A secure remote control system, comprising:
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a key transmitter for generating an electromagnetic radiation signal, the signal including a plurality of pulse pairs, each pair including a start pulse and a stop pulse, with the time interval between each start-and-stop pulse being proportional to a corresponding value in a predetermined key code sequence; a lock receiver for detecting the electromagnetic signal, the receiver including; means for deriving the key code sequence from the time intervals in the received sequence of start-and-stop pulse pairs; means for comparing the derived key code sequence to a predetermined lock code sequence; and means for generating a valid signal if each value in the derived key code sequence corresponds in a predetermined manner to each value in the lock code sequence wherein the means for generating a valid signal further comprises; means for generating a valid signal if each value in the derived key code sequence is the complement of the corresponding value in the lock code sequence. - View Dependent Claims (6, 7, 8, 9, 10)
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Specification