Apparatus and method for remote convenience message reception with signal strength determination

• US 6,472,999 B1
• Filed: 03/08/1999
• Issued: 10/29/2002
• Est. Priority Date: 03/08/1999
• Status: Expired due to Fees

• Current Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Lin, Xing Ping
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): DANG, HUNG Q
• Application Number:
  US09/264,555
• Time in Patent Office: 1,331 Days
• Field of Search: 340/511, 340/5.61, 340/825.69, 340/825.65, 340/3.55, 340/526, 340/10.1, 340/10.33, 340/10.4, 340/10.42, 340/572.1, 340/825.72, 340/825.57, 340/5.64, 340/5.72, 455/226.2, 455/134
• US Class Current: 340/12.18
• CPC Class Codes: G08C 17/02 using a radio link

Abstract

An apparatus (14) and an associated method determine signal strength of a received electromagnetic signal (18) that is comprised of a plurality of pulses that convey a remote convenience function request, and which causes performance of the requested function. A comparator (82) has a first input for receiving an electrical signal (78) with a voltage that varies to convey the remote convenience function request. A second input of the comparator (82) receives a threshold voltage value reference signal (86). An output of the comparator (82) provides an output signal (46) that indicates the occurrence of the voltage of the electrical signal (78) exceeding the threshold value of the reference signal (86). A microprocessor (100) and a threshold change trigger (122) of a controller portion (48) adjust the threshold voltage value of the reference signal (86). A microprocessor (52) and a count memory (126) of the controller portion (48) monitor the output signal (46) of the comparator (82) during adjustment of the threshold voltage value of the reference signal (86) to determine strength of the electromagnetic signal (18).

Claims

1. An apparatus for determining signal strength of a received electromagnetic signal comprised of a plurality of pulses that convey a remote convenience function request, and for causing performance of the requested function, said apparatus comprising:

a comparator having a first input for receiving an electrical signal with a voltage that varies to convey the remote convenience function request, a second input for receiving a threshold voltage value, and an output for providing an output signal indicative of the occurrence of the voltage of the electrical signal exceeding the threshold value;

means for adjusting the threshold voltage value; and

means for monitoring the output signal of the comparator during adjustment of the threshold voltage value to determine strength of the electromagnetic signal;

wherein the output signal of said comparator has a pulse for each occurrence of the voltage of the electrical signal exceeding the threshold value, said means for monitoring includes means for counting the pulses of the output signal.

2. An apparatus as set forth in claim 1, including means for calculating strength of the electromagnetic signal using the counted pulses.

3. An apparatus as set forth in claim 2, wherein the electromagnetic signal has a start portion, the start portion has a predetermined number of pulses and exists for a predetermined duration, the predetermined duration is divided into a plurality of time increments, said means for adjusting includes means for increasing the threshold voltage value by a predetermined amount at an end of every time increment.

4. An apparatus as set forth in claim 3, wherein within said means for calculating, the signal strength is based upon:

5. A method of determining signal strength of an electromagnetic signal, that is comprised of a plurality of pulses that convey a remote convenience function request and that is intended for causing performance of the requested function, said method comprising:

a comparing an electrical signal, that has a voltage which varies to convey the remote convenience function request, with a threshold voltage value;

outputting an output signal indicative of the occurrence of the voltage of the electrical signal exceeding the threshold value wherein the output signal has a pulse for each occurrence of the voltage of the electrical signal exceeding the threshold voltage value;

adjusting the threshold voltage value; and

monitoring the output signal during adjustment of the threshold voltage value to determine strength of the electromagnetic signal wherein the step of monitoring the output signal includes the step of counting the pulses of the output signal.

6. An apparatus for determining signal strength of a received electromagnetic signal and for providing a strength signal indicative of the determined signal strength of the received electromagnetic signal, said apparatus comprising:

a comparator having a first input for receiving an electrical signal, a second input for receiving a threshold voltage value, and an output for providing an output signal indicative of the occurrence of the voltage of the electrical signal exceeding the threshold voltage value, the output signal of said comparator having a pulse for each occurrence of the voltage of the electrical signal exceeding the threshold value;

means for adjusting the threshold voltage value; and

means for monitoring the output signal of the comparator during adjustment of the threshold voltage value to determine signal strength of the electromagnetic signal, said means for monitoring including means for counting the pulses of the output signal and means for providing a strength signal indicative of the signal strength of the electromagnetic signal in response to the counted pulses.