Communication system including diversity antenna queuing

• US 5,842,118 A
• Filed: 12/18/1996
• Issued: 11/24/1998
• Est. Priority Date: 12/18/1996
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Communications, Inc. (Micron Technology, Inc.)
• Inventors: Wood, Clifton W. Jr.
• Primary Examiner(s): LE, THANH C
• Application Number:
  US08/772,173
• Time in Patent Office: 706 Days
• Field of Search: 455/41, 455/59, 455/62, 455/67.1, 455/73, 455/575, 455/101, 455/103, 455/106, 455/133, 455/272, 455/277.1, 455/277.2, 455/288.1, 340/825.54, 342/42, 342/43, 342/44, 342/50, 342/51, 375/267, 375/299
• US Class Current: 455/101
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• 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: H04B 7/0608 Antenna selection according to transmission parameters
• CPC Class Codes: H04B 7/0808 comparing all antennas before reception

Abstract

A wireless communications system comprising a first transponder having a plurality of selectable antennas, and having a stack including locations holding data representing antennas, the stack defining an order in which antennas will be used to attempt communication; a second transponder configured to communicate with the first transponder, wherein the first transponder uses an antenna defined by data in one location of the stack for communication with the second transponder, and, if successful communication with the second transponder is not established, the transponder uses an antenna defined by data in another location of the stack.

Claims

1. A wireless communications system comprising:

a first transponder adapted to be coupled to one of a plurality of selectable antennas, and having a stack including locations holding data representing at least three antennas, the stack defining an order in which antennas will be used to attempt communication; and

a second transponder configured to communicate with the first transponder, wherein the first transponder uses an antenna defined by data in one location of the stack for communication with the second transponder, and, if successful communication with the second transponder is not established, the first transponder uses different antennas in successive communications attempts, in the defined order, and wherein the first transponder rearranges the stack after a successful communication if the successful communication did not occur using the antenna defined by data in the first mentioned location of the stack.

2. A wireless communications system in accordance with claim 1 wherein the first transponder communicates with the second transponder using backscatter communications.

3. A wireless communications system in accordance with claim 1 wherein the first transponder communicates with the second transponder using backscatter communications, wherein the first transponder employs separate receive and transmit antennas, and wherein the respective locations of the stack store data representing antenna pairs including one transmit antenna and one receive antenna.

4. A wireless communications system in accordance with claim 1 wherein the second transponder comprises an integrated circuit including a transmitter, a receiver, and a microprocessor.

5. A wireless communications system in accordance with claim 1 wherein the second transponder comprises a radio frequency identification device including memory storing data identifying the second transponder.

6. A wireless communications system in accordance with claim 1 wherein the first transponder rearranges the stack if successful communication is not established using the antenna defined by data in the first mentioned location of the stack such that data representing an antenna using which successful communications is established is moved to the first mentioned location of the stack.

7. A wireless communications system in accordance with claim 1 wherein the first transponder rearranges the stack if successful communication is not established using the antenna defined by data in the first mentioned location of the stack such that data representing an antenna using which successful communications is established is moved closer to the first mentioned location of the stack.

8. A wireless communications system in accordance with claim 1 and further comprising a plurality of transmit antennas, and wherein one of the transmit antennas is spaced apart from another of the transmit antennas by at least one wavelength.

9. A wireless communications system in accordance with claim 8 and further comprising a plurality of receive antennas, and wherein one of the receive antennas is spaced apart from another of the receive antennas by at least one wavelength.

10. A radio frequency communications system comprising:

a first radio frequency transponder adapted to be coupled to one of a plurality of selectable antennas, and including a stack having rows holding data representing antennas, including a top row and a bottom row, the stack defining an order, from the top of the stack to the bottom of the stack, in which antennas will be used to attempt communication;

a second radio frequency transponder configured to communicate with the first transponder, wherein the first transponder uses an antenna defined by data in the top row of the stack for communication with the second transponder, and, if successful communication with the second transponder is not established, the transponder uses an antenna defined by data in the next highest row of the stack; and

a data arranger selectively rearranging the order of the data in the stack, and operable in a first mode, wherein data representing the first antenna that resulted in successful communication is moved to the top of the stack, and a second mode, wherein data representing the first antenna that resulted in successful communication is swapped with data in the row above the row holding the data representing the first antenna that resulted in successful communication.

11. A radio frequency communications system in accordance with claim 10 wherein the data arranger is further operable in a third mode wherein data is the stack is not rearranged regardless of which antenna selection results in successful communication with the second transponder.

12. A radio frequency communications system in accordance with claim 10 wherein the first transponder communicates with the second transponder using backscatter communications and, after the first transponder sends data to the second transponder, the first transponder transmits a continuous wave to the second transponder, wherein the communication system includes a dipole antenna coupled to the second transponder, the dipole antenna having two halves, and wherein the second transponder selectively reflects and does not reflect the continuous wave by either shorting or not shorting the two halves of the dipole antenna.

13. A radio frequency communications system in accordance with claim 10 wherein the first transponder communicates with the second transponder using backscatter communications, wherein the first transponder employs separate receive and transmit antennas, and wherein the respective rows of the stack store data representing antenna pairs respectively defined by one transmit antenna and one receive antenna.

14. A radio frequency communications system in accordance with claim 10 wherein the second transponder comprises a radio frequency identification device including memory storing data identifying the second transponder.

15. A radio frequency communications system wireless communications system in accordance with claim 10 and further comprising a plurality of transmit antennas, wherein the first transponder includes a switch for selecting which of the transmit antennas will be employed for wireless transmission by the first transponder, and wherein one of the transmit antennas is spaced apart from another of the transmit antennas by at least one wavelength.

16. A wireless communications method comprising:

defining a queue including locations holding data representing selectable antennas, the queue defining an order in which antennas will be used to attempt communication;

causing a first transponder to use an antenna defined by data in one location of the queue for communication with a second transponder, and, if successful communication with the second transponder is not established, causing the first transponder to attempt communications using different antennas in the order defined by the queue, until a successful communication occurs; and

after the successful communication rearranging the queue in accordance with a selected one of either a first selection method or a second selection method different from the first selection method.

17. A wireless communications method in accordance with claim 16 and further comprising causing the first transponder to communicate with the second transponder using backscatter communications.

18. A wireless communications method in accordance with claim 16 and further comprising causing the first transponder to communicate with the second transponder using backscatter communications, wherein the first transponder employs separate receive and transmit antennas, and further comprising arranging the queue such that respective locations of the queue store data representing antenna pairs including one transmit antenna and one receive antenna.

19. A wireless communications method in accordance with claim 16 and further comprising causing the second transponder to store data identifying the second transponder and to transmit that data to the first transponder in response to a wireless command to do so from the first transponder.

20. A wireless communications method in accordance with claim 16 wherein rearranging the queue comprises moving data representing an antenna using which successful communications is established to the first mentioned location of the queue.

21. A wireless communications method in accordance with claim 16 wherein rearranging the queue comprises moving data representing an antenna using which successful communications is established closer to the first mentioned location of the queue.

22. A wireless communications method in accordance with claim 16 and further comprising providing a plurality of transmit antennas, and spacing one of the transmit antennas from another of the transmit antennas by at least one wavelength.

23. A wireless communications method in accordance with claim 16 and further comprising providing a plurality of receive antennas, and spacing one of the receive antennas from another of the receive antennas by at least one wavelength.

24. A radio frequency communications method comprising:

defining a queue having rows holding data representing antennas, including a top row and a bottom row, the queue defining an order, from the top of the queue to the bottom of the queue, in which antennas will be used to attempt communication;

causing a first transponder to use an antenna defined by data in the top row of the queue for communication with a second transponder, and, if successful communication with the second transponder is not established, causing the first transponder to use an antenna defined by data in the next highest row of the queue; and

rearranging the order of the data in the queue in accordance with a selected one of a first mode, wherein data representing the first antenna that resulted in successful communication is moved to the top of the queue, and a second mode, wherein data representing the first antenna that resulted in successful communication is swapped with data in the row above the row holding the data representing the first antenna that resulted in successful communication.

25. A radio frequency communications method in accordance with claim 24 wherein the rearranging step further includes a selectable third mode, wherein data is the queue is not rearranged regardless of which antenna selection results in successful communication with the second transponder.

26. A radio frequency communications method in accordance with claim 24 and further comprising the step of causing the first transponder to communicate with the second transponder using backscatter communications and, after the first transponder sends data to the second transponder, causing the first transponder to transmit a continuous wave to the second transponder, and causing the second transponder to communicate with the first transponder by selectively reflecting and not reflecting the continuous wave by either shorting or not shorting two halves of a dipole antenna.

27. A radio frequency communications method in accordance with claim 24 and further comprising causing the first transponder to communicate with the second transponder using backscatter communications, and coupling the first transponder to separate receive and transmit antennas, and storing data in the respective rows of queue representing antenna pairs respectively including one transmit antenna and one receive antenna.

28. A radio frequency communications method in accordance with claim 24 and further comprising the step of storing identifying data in the second transponder, and causing the second transponder to communicate the identifying data to the first transponder in response to a command from the first transponder.

29. A backscatter radio frequency communications system comprising:

a plurality of transmit antennas and receive antennas;

a first radio frequency transponder selectively coupled to an antenna pair defined by one of the transmit antennas and one of the receive antennas, and including a stack having rows holding data representing antenna pairs, including a top row and a bottom row, the stack defining an order, from the top of the stack to the bottom of the stack, in which antennas will be used by the first transponder to attempt communication;

a second radio frequency transponder configured to communicate with the first transponder, wherein the first transponder uses an antenna pair defined by data in the top row of the stack for communication with the second transponder, and, if successful communication with the second transponder is not established, the transponder uses an antenna pair defined by data in the next highest row of the stack, the first transponder being configured to communicate with the second transponder using backscatter communications wherein, after the first transponder sends data to the second transponder, the first transponder transmits a continuous wave to the second transponder;

a dipole antenna coupled to the second transponder, the dipole antenna having two halves, the second transponder being configured to reflect and not reflect the continuous wave by either shorting or not shorting the two halves of the dipole antenna to communicate with the first transponder; and

a data arranger selectively rearranging the order of the data in the stack, and operable in a first mode, wherein data representing the first antenna pair that resulted in successful communication is moved to the top of the stack, a second mode, wherein data representing the first antenna pair that resulted in successful communication is swapped with data in the row above the row holding the data representing the first antenna that resulted in successful communication, and a third mode wherein data is the stack is not rearranged regardless of which antenna selection results in successful communication with the second transponder.

30. A radio frequency communications system comprising:

a first radio frequency transponder adapted to be coupled to one of a plurality of selectable antennas, and including memory holding rows of data representing antennas, including a first row and a last row, the rows defining an order, from the first row to the last row, in which antennas will be used to attempt communication;

a second radio frequency transponder configured to communicate with the first transponder, wherein the first transponder uses an antenna defined by data in the first row for communication with the second transponder, and, if successful communication with the second transponder is not established, the transponder uses an antenna defined by data in the next row; and

a data arranger selectively rearranging the order of the data in the memory, and operable in a first mode, wherein data representing the first antenna that resulted in successful communication is moved to the first row, and a second mode, wherein data representing the first antenna that resulted in successful communication is swapped with data in the row above the row holding the data representing the first antenna that resulted in successful communication.

31. A radio frequency communications system comprising:

a first radio frequency transponder adapted to be coupled to one of a plurality of selectable antennas, and including memory holding locations of data representing antennas, including a first location and a last location, the locations defining an order, from the first location to the last location, in which antennas will be used to attempt communication;

a second radio frequency transponder configured to communicate with the first transponder, wherein the first transponder uses an antenna defined by data in the first location for communication with the second transponder, and, if successful communication with the second transponder is not established, the transponder uses an antenna defined by data in the next location; and

a data arranger selectively rearranging the order of the data in the memory, and operable in a first mode, wherein data representing the first antenna that resulted in successful communication is moved to the first location, and a second mode, wherein data representing the first antenna that resulted in successful communication is swapped with data in a location closer to the first location.

32. A radio frequency communications method comprising:

defining a queue having rows holding data representing antennas, including a top row and a bottom row, the queue defining an order, from the top of the queue to the bottom of the queue, in which antennas will be used to attempt communication;

causing a first transponder to use an antenna defined by data in one of the rows of the queue for communication with a second transponder, and, if successful communication with the second transponder is not established, causing the first transponder to use an antenna defined by data in the next highest row of the queue; and

rearranging the order of the data in the queue in accordance with a selected one of a first mode, wherein data representing the first antenna that resulted in successful communication is moved to the top of the queue, and a second mode, wherein data representing the first antenna that resulted in successful communication is swapped with data in the row above the row holding the data representing the first antenna that resulted in successful communication.

33. A method in accordance with claim 32 wherein the rearranging occurs after a successful communication with the second transponder, but prior to a subsequent communication attempt.