RFID readers and RFID tags communicating using extensible bit vectors

• US 7,030,786 B2
• Filed: 01/07/2005
• Issued: 04/18/2006
• Est. Priority Date: 05/24/2004
• Status: Active Grant

• Current Assignee: Impinj, Inc.
• Original Assignee: Impinj, Inc.
• Inventors: Diorio, Christopher J., Kaplan, David
• Primary Examiner(s): Jeanglaude, Jean Bruner
• Application Number:
  US11/031,459
• Publication Number:
  US 20050270189A1
• Time in Patent Office: 466 Days
• Field of Search: 341/50, 341/53, 341/70, 72/151, 340/10.1, 340/10.41
• US Class Current: 341/50
• 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 7/10297 arrangements for handling protocols designed for non-contact record carriers such as RFIDs NFCs, e.g. ISO/IEC 14443 and 18092 cryptographic protocols H04L9/00; network security protocols H04L63/00; real-time communication protocols in data switching networks H04L65/00; network protocols for data switching network services H04L67/00

Abstract

RFID system components, such as readers and tags, communicate by transmitting and receiving a wave that conveys a bit stream. Informing signals, such as special bits, are inserted in the stream between words. An informing signal indicates whether a certain word is the last word in the stream or not.

Claims

1. A radio frequency identification (RFID) system component, comprising:

an antenna that is arranged to receive a wave;

a demodulator that is arranged to generate symbols from the wave;

a mapper/decoder that is arranged to generate a stream of bits from the symbols; and

a processing block that is arranged to;

(a) isolate a group of the bits from the stream,

(b) designate at least one of the isolated bits as an informing signal,

(c) designate the remaining bits of the group as a word,

(d) append the word to a previously similarly designated word for forming a reception block, and

(e) if the informing signal does not equal a preset termination return to (a), else terminate appending and perform an action that uses the reception block as one of a memory address and content.

2. The RFID system component of claim 1, wherein the RFID system component is an RFID tag, and the wave is received from an RFID reader.

3. The RFID system component of claim 1, wherein the RFID system component is an RFID reader, and the wave is received from an RFID tag.

4. The RFID system component of claim 1, wherein the processing block is further arranged to determine whether the stream is associated with one of a memory address and content.

5. The RFID system component of claim 4, wherein if the stream is associated with a memory address, the processing block is further arranged to access the memory address for at least one of retrieving data and storing data.

6. The RFID system component of claim 4, wherein if the stream is associated with content, the processing block is further arranged to determine whether the content includes at least a portion of a command.

7. The RFID system component of claim 1, wherein a size of the group is one of 8 and 16.

8. The RFID system component of claim 1, wherein the termination is one of a 0 bit and a 1 bit.

9. A method for a component of an RFID system comprising:

(a) receiving a stream of bits;

(b) isolating a group of the bits from the stream;

(c) designating at least one of the isolated bits as an informing signal;

(d) designating the remaining bits of the group of symbols as a word;

(e) appending the word to a previously similarly designated word for forming a reception block; and

(f) if the informing signal does not equal a preset termination returning to (b), else terminating appending and performing an action that uses the reception block as one of a memory address and content.

10. The method of claim 9, wherein the termination is one of a 0 bit and a 1 bit.

11. The method of claim 9, further comprising:

determining a size of the group prior to (b).

12. The method of claim 11, further comprising:

receiving a wave; and

demodulating the wave to decode the size.

13. The method of claim 9, wherein the group has a size of one of 8 and 16.

14. The method of claim 9, further comprising:

receiving a wave;

demodulating the wave to generate symbols; and

mapping/decoding the symbols to generate the stream of bits to be received in (a).

15. The method of claim 14, wherein the wave is received in an RFID tag from an RFID reader.

16. The method of claim 14, wherein the wave is received in an RFID reader from an RFID tag.

17. The method of claim 9, wherein the informing signal is the first bit of the group of bits.

18. The method of claim 9, wherein the informing signal is the last bit of the group of bits.

19. The method of claim 9, wherein the group is encoded as an Extensible Bit Vector (EBV).

20. A radio frequency identification (RFID) system component, comprising:

a processing circuit that is arranged to;

retrieve a block of bits,

isolate up to a word of the bits that occur sequentially in the block,

append to a transmission stream the bits of the isolated word and at least one informing signal, wherein the informing signal equals a preset termination if the isolated bits are the last ones in the block, and does not equal the preset termination otherwise, and

if there remain bits in the block that have not been isolated, return to isolating more of the bits, else forward the transmission stream for transmission;

a mapper/encoder that is arranged to generate symbols from the transmission stream;

a modulator that is arranged to modulate a wave with the symbols; and

an antenna that is arranged to transmit the modulated wave.

21. The RFID system component of claim 20, wherein

the termination is one of a 0 bit and a 1 bit.

22. The RFID system component of claim 20, wherein

the block of bits is retrieved from a memory.

23. The RFID system component of claim 20, wherein

the group is encoded as an Extensible Bit Vector (EBV).

24. The RFID system component of claim 20, wherein

a size of the word is one of 7 and 14.

25. The RFID system component of claim 20, wherein

the RFID system component is an RFID tag, and the wave is transmitted to an RFID reader.

26. The RFID system component of claim 20, wherein

the RFID system component is an RFID reader, and the wave is transmitted to an RFID tag.

27. The RFID system component of claim 20, the processing circuit is further arranged to:

determine a size of the word prior to isolating a group.

28. A method for a component of an RFID system comprising:

(a) retrieving a block of bits;

(b) isolating a word of the bits that occur sequentially in the block;

(c) appending to a transmission stream the bits of the isolated word and at least one informing signal, wherein the informing signal equals a preset termination if the isolated bits are the last ones in the block, and does not equal the preset termination otherwise; and

(d) if there remain symbols in the block that have not been isolated, returning to (b), else transmitting a wave that conveys the transmission stream.

29. The method of claim 28, further comprising:

encoding the transmission stream into symbols; and

modulating the wave with the symbols prior to transmitting it.

30. The method of claim 28, wherein the wave is transmitted from an RFID tag to an RFID reader.

31. The method of claim 28, wherein the wave is transmitted from an RFID reader to an RFID tag.

32. The method of claim 28, wherein

at (c) the informing signal is appended to the transmission stream before the bits of the isolated word.

33. The method of claim 28, wherein

at (c) the informing signal is appended to the transmission stream after the bits of the isolated word.

34. The method of claim 28, further comprising:

determining a size of the word.

35. The method of claim 28, wherein

a size of the word is one of 7 and 14.

36. The method of claim 28, wherein

the block of bits is retrieved from a memory.

37. The method of claim 28, wherein

the termination is one of a 0 bit and a 1 bit.