Robust early detection through signal repetition in mixed-rate wireless communications

• US 10,419,971 B2
• Filed: 02/02/2016
• Issued: 09/17/2019
• Est. Priority Date: 02/04/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Vermani, Sameer, Tian, Bin, Tian, Tao
• Primary Examiner(s): Mered, Habte
• Application Number:
  US15/013,959
• Publication Number:
  US 20160227436A1
• Time in Patent Office: 1,323 Days
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365

Abstract

A method of wirelessly communicating includes generating, at a wireless device, a packet including a first preamble field. The method further includes generating a first repeated preamble field by multiplying the first preamble field by a first frequency-domain polarity sequence. The method further includes transmitting the packet from the wireless device. The packet includes the first preamble field and the first repeated preamble field.

Claims

1. A method of wireless communication, comprising:

receiving, at a first wireless device, a packet transmitted from a second wireless device;

identifying a first preamble field in the packet;

identifying a repeated preamble field in the packet, wherein the repeated preamble field is the first preamble field multiplied by a frequency-domain polarity sequence, wherein the first frequency-domain polarity sequence comprises a predetermined sequence of +1 and −

1; and

generating a corrected preamble field by multiplying the repeated preamble field by the frequency-domain polarity sequence at the first device to reverse the frequency-domain polarity sequence multiplication performed by the second device.

2. The method of claim 1, further comprising performing an auto-correlation between the first preamble field and the corrected preamble field.

3. The method of claim 2, further comprising:

determining a result of the auto-correlation;

comparing the result of the auto-correlation to a threshold; and

refraining from decoding the packet in response to a determination that the result of the auto-correlating is below the threshold.

4. The method of claim 2, further comprising:

determining a result of the auto-correlation;

comparing the result of the auto-correlation to a threshold; and

interpreting the packet as a first type of packet, instead of a second type of packet, in response to a determination that the result of the auto-correlation is above the threshold.

5. The method of claim 1, wherein the first preamble field is decodable by the plurality of devices, and the packet comprises a second preamble field decodable by only a subset of the plurality of devices.

6. The method of claim 1, further comprising:

identifying a length indication in the first preamble field; and

determining whether a value of the length indication is evenly divisible by three;

interpreting the packet as a first type of packet, instead of a second type of packet, in response to a determination that the value of the length indication is not evenly divisible by three.

7. The method of claim 1, wherein:

the first preamble field comprises a legacy signal (L-SIG) field; and

the first repeated preamble field comprises a repeated legacy signal (RL-SIG) field.

8. The method of claim 1, wherein a polarity of the repeated preamble field does not carry additional information.

9. An apparatus configured to perform wireless communication, comprising:

a receiver configured to receive a packet at a first wireless device transmitted from a second wireless device; and

a processor coupled with the receiver and configured to;

identify a first preamble field in the packet;

identify a repeated preamble field in the packet, wherein the repeated preamble field is the first preamble field multiplied by a frequency-domain polarity sequence, wherein the frequency-domain polarity sequence comprises a predetermined sequence of +1 and −

1; and

generate a corrected preamble field by multiplying the repeated preamble field by the frequency-domain polarity sequence at the first device to reverse the frequency-domain polarity sequence multiplication performed by the second device.

10. The apparatus of claim 9, wherein the processor is further configured to perform an auto-correlation between the first preamble field and the corrected preamble field.

11. The apparatus of claim 10, wherein the processor is further configured to:

determine a result of the auto-correlation;

compare the result of the auto-correlation to a threshold; and

refrain from decoding the packet in response to a determination that the result of the auto-correlating is below the threshold.

12. The apparatus of claim 10, wherein the processor is further configured to:

determine a result of the auto-correlation;

compare the result of the auto-correlation to a threshold; and

interpret the packet as a first type of packet, instead of a second type of packet, in response to a determination that the result of the auto-correlation is above the threshold.

13. The apparatus of claim 9, wherein the first preamble field is decodable by the plurality of devices, and the packet comprises a second preamble field decodable by only a subset of the plurality of devices.

14. The apparatus of claim 9, wherein the processor is further configured to:

identify a length indication in the first preamble field; and

determine whether a value of the length indication is evenly divisible by three;

interpret the packet as a first type of packet, instead of a second type of packet, in response to a determination that the value of the length indication is not evenly divisible by three.

15. The apparatus of claim 9, wherein:

the first preamble field comprises a legacy signal (L-SIG) field; and

the first repeated preamble field comprises a repeated legacy signal (RL-SIG) field.

16. The apparatus of claim 9, wherein a polarity of the repeated preamble field does not carry additional information.

17. An apparatus configured to perform wireless communication, comprising:

means for receiving, at a first wireless device, a packet transmitted from a second wireless device;

means for identifying a first preamble field in the packet;

means for identifying a repeated preamble field in the packet, wherein the repeated preamble field is the first preamble field multiplied by a frequency-domain polarity sequence, wherein the frequency-domain polarity sequence comprises a predetermined sequence of +1 and −

1; and

means for generating a corrected preamble field by multiplying the repeated preamble field by the frequency-domain polarity sequence at the first device to reverse the frequency-domain polarity sequence multiplication performed by the second device.

18. A non-transitory computer-readable medium comprising code that, when executed, causes an apparatus to:

receive, at a first wireless device, a packet transmitted from a second wireless device;

identify a first preamble field in the packet;

identify a repeated preamble field in the packet, wherein the repeated preamble field is the first preamble field multiplied by a frequency-domain polarity sequence, wherein the frequency-domain polarity sequence comprises a predetermined sequence of +1 and −

1; and

generate a corrected preamble field by multiplying the repeated preamble field by the frequency-domain polarity sequence at the first device to reverse the frequency-domain polarity sequence multiplication performed by the second device.