Data collision detection device and method

• US 7,352,771 B2
• Filed: 10/06/2003
• Issued: 04/01/2008
• Est. Priority Date: 10/08/2002
• Status: Active Grant

• Current Assignee: Colder Products Company (Dover Corporation)
• Original Assignee: Colder Products Company (Dover Corporation)
• Inventors: Garber, Richard Stewart
• Primary Examiner(s): Ngo; Ricky Q.
• Assistant Examiner(s): Hailu; Kibrom T
• Application Number:
  US10/679,946
• Publication Number:
  US 20040130438A1
• Time in Patent Office: 1,639 Days
• Field of Search: 370/445, 370/447, 370/242, 370/252, 370/446, 375/360, 375/361, 375/282
• US Class Current: 370/445
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10029 the collision being resolved in the time domain, e.g. using binary tree search or RFID responses allocated to a random time slot

Abstract

A data collision detection device that includes a means for de-modulating at least one carrier signal corresponding to a received modulated subcarrier signal from at least one data transmitter to recover the subcarrier signal from the carrier signal. A microcontroller is operatively connected with the means for recovering a subcarrier signal. The microcontroller includes a means for decoding a recovered subcarrier signal. The means for decoding the recovered subcarrier signal is capable of interpreting signal transitions in the recovered subcarrier signal, and is capable of detecting data collisions in the recovered subcarrier signal when in the presence of a plurality of modulated subcarrier signals.

Claims

1. A data collision detection device for decoding received signals from data transmitters, comprising:

a means for de-modulating at least one modulated carrier signal corresponding to a received signal from at least one data transmitter; and

a module operatively coupled with the means for de-modulating, the module including a means for decoding a recovered subcarrier signal recovered from the means for de-modulating, the means for decoding the recovered subcarrier signal being capable of interpreting signal transitions in the recovered subcarrier signal and being capable of detecting a data collision within the recovered subcarrier signal in the presence of a plurality of modulated carrier signals detected in the recovered subcarrier signal;

wherein the means for decoding a recovered subcarrier signal includes a means for counting a number of transitions before and after a bit-center of the recovered subcarrier signal; and

wherein the means for decoding a recovered subcarrier signal is configured to detect a data collision when the number of transitions before the bit-center and the number of transitions after the bit-center are substantially equal.

2. A data collision detection device for decoding received signals from data transmitters, comprising:

a module configured to de-modulate at least one modulated carrier signal conesponding to a received signal from at least one data transmitter to recover a subcarrier signal from the carrier signal; and

a microcontroller operatively coupled to the module, the microcontroller being configured to count a number of transitions before and after a bit-center of the subcarrier signal and thereby detect a data collision;

wherein the microcontroller is configured to detect a data collision when the number of transitions before the bit-center and the number of transitions after the bit-center are substantially equal.

3. A method for detecting data collisions using a data collision detection device, comprising:

de-modulating a received signal to recover a subcarrier signal;

decoding the recovered subcarrier signal to interpret signal transitions in the recovered subcarrier signal; and

detecting a presence of data collisions in the recovered subcarrier signal, including;

determining a bit-center;

counting a number of transitions before and after the bit-center; and

determining the presence of data collisions when the number of transitions before the bit-center and the number of transitions after the bit-center are substantially equal.

4. The method of claim 3, wherein the step of decoding the recovered subcarrier signal further comprises:

determining a bit-center;

measuring a number of transitions before and after the bit-center;

detecting a logic 1 when the number of transitions before the bit-center is substantially greater than the number of transitions after the bit-center; and

detecting a logic 0 when the number of transitions after the bit-center is substantially greater than the number of transitions before the bit-center.

5. The method of claim 3, further comprising sorting signals transmitted from a plurality of data transmitters that are detected in the recovered subcarrier signal.

6. A method for detecting data collisions, comprising:

providing a data collision detection device including a means for de-modulating a received signal corresponding to at least one carrier signal from at least one data transmitter to recover a subcarrier signal from the received signal, and a microcontroller operatively connected with the means for de-modulating and including a means for decoding the subcarrier signal;

de-modulating the received signal to the subcarrier signal using the means for de-modulating the received signal to recover the subcarrier signal;

transferring the recovered subcarrier signal to the microcontroller;

decoding the recovered subcarrier signal using the means for decoding the recovered subcarrier signal to interpret signal transitions in the recovered subcarrier signal; and

detecting the presence of data collisions resulting from the decoding and interpretation of the recovered subcarrier signal, including;

determining a bit-center;

measuring a number of transitions before and after the bit-center; and

determining the presence of data collisions when the number of transitions before the bit-center and the number of transitions after the bit-center are substantially equal.

7. The method of claim 6, wherein the step of decoding the recovered subcarrier signal further comprises:

determining a bit-center;

measuring a number of transitions before and after the bit-center;

detecting a logic 1 when the number of transitions before the bit-center is substantially greater than the number of transitions after befere the bit-center; and

detecting a logic 0 when the number of transitions after the bit-center is substantially greater than the number of transitions before the bit-center.

8. The method of claim 6, further comprising sorting signals transmitted from a plurality of data transmitters that are detected in the recovered subcarrier signal.