Low-complexity synchronization header detection

Patent metadata

Field	Value
Publication number	US-11736269-B2
Application number	US-202117488364-A
Country	US
Kind code	B2
Filing date	Sep 29, 2021
Priority date	Dec 5, 2018
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

A technique of separating a sequence of modulation shift keying (MSK) symbols into a first portion and a second portion and separately comparing the first portion of the sequence of MSK symbols and the second portion of the sequence of MSK symbols against a first portion of a reference sequence of MSK symbols and a second portion of the reference sequence of MSK symbols allows a low complexity detection of a start field delimiter in a wireless communication packet.

First claim

We claim:

1. A start field delimiter detector, comprising:
a minimum-shift keying (MSK) demodulation circuit, configured to translate offset quadrature phase shift keying chips into a set of sequences of MSK symbols;
a first circuit, configured to compare whether a first portion of each sequence of MSK symbols matches with a first portion of a respective sequence of reference MSK symbols;
a second circuit, configured to compare whether a second portion of each sequence of MSK symbols matches with a second portion of the respective sequence of reference MSK symbols, wherein the second portion of each respective sequence of reference MSK symbols is invariant; and
a start field delimiter detector circuit configured to indicate detection of a start field delimiter in a packet responsive to the comparison by the first circuit and the comparison by the second circuit.

2. The start field delimiter detector of claim 1 ,
wherein each sequence of the set of sequences of MSK symbols is a sequence of 32 MSK symbols, and
wherein the first portion of each sequence of the set of sequences of MSK symbols is a first MSK symbol of the sequence of 32 MSK symbols.

3. The start field delimiter detector of claim 1 ,
wherein each sequence of the set of sequences of MSK symbols is a sequence of 32 MSK symbols, and
wherein the second portion of each sequence of the set of sequences of MSK symbols is a second through 31st MSK symbols of the sequence of 32 MSK symbols.

4. The start field delimiter detector of claim 1 ,
wherein the start field delimiter is an IEEE 802.15.4g start field delimiter.

5. The start field delimiter detector of claim 1 ,
wherein the first circuit is configured to compute a Hamming distance between the first portion of each of the set of sequences of MSK symbols and the first portion of each of the set of sequences of reference MSK symbols, and
wherein the first circuit is configured to determine a first match responsive to the Hamming distance having a first relationship with a first threshold value.

6. The start field delimiter detector of claim 1 ,
wherein the second circuit is configured to compute a Hamming distance between the second portion of each of the set of sequences of MSK symbols and the second portion of each of the set of sequences of references MSK symbols, and
wherein the second circuit is configured to determine a second match responsive to the Hamming distance having a second relationship with a second threshold value.

7. A receiver, comprising:
circuitry to demodulate a signal comprising offset quadrature phase shift keying chips into a set of sequences of minimum-shift keying (MSK) symbols; and
a microcontroller configured to detect a start field delimiter in the received set of sequences of MSK symbols, the microcontroller comprising:
a first circuit, configured to compare whether a first portion of each sequence of MSK symbols matches with a first portion of a respective sequence of reference MSK symbols;
a second circuit, configured to compare whether a second portion of each sequence of MSK symbols matches with a second portion of the respective sequence of reference MSK symbols, wherein the second portion of each respective sequence of reference MSK symbols is invariant; and
a start field delimiter detector circuit configured to indicate detection of a start field delimiter in a packet responsive to the comparison by the first circuit and the comparison by the second circuit.

8. The receiver of claim 7 ,
wherein each sequence of the set of sequences of MSK symbols is a sequence of 32 MSK symbols, and
wherein the first portion of each sequence of the set of sequences of MSK symbols is a first MSK symbol of the sequence of 32 MSK symbols.

9. The receiver of claim 7 ,
wherein each sequence of the set of sequences of MSK symbols is a sequence of 32 MSK symbols, and
wherein the second portion of each sequence of the set of sequences of MSK symbols is a second through 31st MSK symbols of the sequence of 32 MSK symbols.

10. The receiver of claim 7 ,
wherein the start field delimiter is an IEEE 802.15.4g start field delimiter.

11. The receiver of claim 7 ,
wherein the first circuit is configured to compute a Hamming distance between the first portion of each of the set of sequences of MSK symbols and the first portion of each of the set of sequences of reference MSK symbols, and
wherein the first circuit is configured to determine a first match responsive to the Hamming distance having a first relationship with a first threshold value.

12. The receiver of claim 7 ,
wherein the second circuit is further configured to compute a Hamming distance between the second portion of each of the set of sequences of MSK symbols and the second portion of each of the set of sequences of references MSK symbols, and
wherein the second circuit is further configured to determine a second match responsive to the Hamming distance having a first relationship with a second threshold value.

13. A method of detecting a start field delimiter in a packet, comprising:
converting a set of offset quadrature phase shift keying chips into a set of sequences of minimum-shift keying (MSK) symbols;
comparing in a first comparison whether a first portion of each sequence of MSK symbols matches with a first portion of a respective sequence of reference MSK symbols that correspond to a start field delimiter;
comparing in a second comparison whether a second portion of each sequence of MSK symbols matches with a second portion of the respective sequence of reference MSK symbols, wherein the second portion of each respective sequence of reference MSK symbols is invariant; and
detecting the start field delimiter in the packet responsive to the first comparison indicating a first match and the second comparison indicating a second match.

14. The method of claim 13 ,
wherein each sequence of the set of sequences of MSK symbols is a sequence of 32 MSK symbols,
wherein the first portion of each sequence of the set of sequences of MSK symbols is a first MSK symbol of the sequence of 32 MSK symbols, and
wherein the second portion of each sequence of the set of sequences of MSK symbols is a second through 31st MSK symbols of the sequence of 32 MSK symbols.

15. The method of claim 13 ,
wherein the start field delimiter is an IEEE 802.15.4g start field delimiter.

16. The method of claim 13 ,
wherein comparing in the first comparison comprises computing a Hamming distance between the first portion of each of the set of sequences of MSK symbols and the first portion of each of the set of sequences of reference MSK symbols, and
wherein the first comparison indicates the first match responsive to the Hamming distance having a first relationship with a first threshold value.

17. The method of claim 13 ,
wherein comparing in the second comparison comprises computing a Hamming distance between the second portion of each of the set of sequences of MSK symbols and the second portion of each of the set of sequences of references MSK symbols, and
wherein the second comparison indicates the second match responsive to the Hamming distance having a first relationship with a second threshold value.

18. An apparatus, comprising:
a microcontroller, programmed to:
convert a set of offset quadrature phase shift keying chips into a set of sequences of minimum-shift keying (MSK) symbols;
compare in a first comparison whether a first portion of each sequence of MSK symbols matches with a first portion of a respective sequence of reference MSK s

Assignees

• Texas Instruments Inc

Inventors

• Qiu Wenxun
• Motos Tomas
• Moe Marius

Classifications

• H04L7/042 Primary

  Detectors therefor, e.g. correlators, state machines (digital correlators in general G06F17/15) · CPC title

• H04B1/70735

  Code identification (H04B1/7083 takes precedence) · CPC title

• H04L27/3405

  Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power · CPC title

• H04L27/3455

  in order to facilitate carrier recovery at the receiver end, e.g. by transmitting a pilot or by using additional signal points to allow the detection of rotations · CPC title

• H04L27/3836

  in which the carrier is recovered using the received modulated signal or the received IF signal, e.g. by detecting a pilot or by frequency multiplication · CPC title