Methods, systems, and articles of manufacture for joint decoding of packets in wireless networks using chirp spread-spectrum modulation

Patent metadata

Field	Value
Publication number	US-10735047-B2
Application number	US-201916374981-A
Country	US
Kind code	B2
Filing date	Apr 4, 2019
Priority date	Apr 5, 2018
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

A method of providing wireless communications in a wireless network can include wirelessly receiving a chirp spread-spectrum modulated signal at a first gateway device, the chirp spread-spectrum modulated signal being transmitted by a remote client device. The chirp spread-spectrum modulated signal can be demodulated at the first gateway device to provide demodulated data at the first gateway device. The demodulated data can be processed to provide an indication that a decode of a packet including the demodulated data failed. Time adjacent chirps included in the demodulated data can be combined to provide combined data at the first gateway device. A message can be transmitted from the first gateway device to a remote server responsive to an amplitude of the combined data exceeding a threshold value and the indication that the decode of the packet including the demodulated data failed.

First claim

What is claimed:

1. A method of providing wireless communications in a wireless network, the method comprising:
wirelessly receiving a chirp spread-spectrum modulated signal at a first gateway device, the chirp spread-spectrum modulated signal being transmitted by a remote client device;
demodulating the chirp spread-spectrum modulated signal at the first gateway device to provide demodulated data at the first gateway device;
processing the demodulated data to provide an indication that a decode of a packet including the demodulated data failed;
combining time adjacent chirps included in the demodulated data to provide combined data at the first gateway device; and
transmitting a message from the first gateway device to a remote server responsive to an amplitude of the combined data exceeding a threshold value and the indication that the decode of the packet including the demodulated data failed.

2. The method of claim 1 wherein the combining the time adjacent chirps includes:
sub-sampling the time adjacent chirps to alias different frequency ones of the time adjacent chirps into a common frequency component to provide the combined data; and
determining that the amplitude of the common frequency component exceeds the threshold value.

3. The method of claim 1 wherein transmitting the message from the first gateway device to the remote server comprises transmitting an indication of a time at which the chirp spread-spectrum modulated signal was received at the first gateway device and a channel frequency for the chirp spread-spectrum modulated signal.

4. The method of claim 3 wherein the message comprises a first message including an indication that the first gateway device detected a first potential packet identified by a first time at which the chirp spread-spectrum modulated signal was received at the first gateway device and a first channel frequency for the chirp spread-spectrum modulated signal, the method further comprising:
receiving the first message from the first gateway device at the remote server;
receiving a second message from a second gateway device at the remote server, the second message including an indication that the second gateway device detected a second potential packet identified by a second time at which a chirp spread-spectrum modulated signal was received at the second gateway device and a second channel frequency for the chirp spread-spectrum modulated signal received at the second gateway device;
determining whether the first and second potential packets are the same packet based on a similarity between the first and second times and geographic proximity of the first and second gateway devices to one another to provide a match signal;
sending a third message to the first gateway device responsive to the match signal, the third message including a request to the first gateway device for samples of demodulated data stored in a first buffer circuit in the first gateway device, the data identified by the first time at which the chirp spread-spectrum modulated signal was received at the first gateway device and the first channel frequency; and
sending a fourth message to the second gateway device responsive to the match signal, the fourth message including a request to the second gateway device for samples of demodulated data stored in a second buffer circuit in the second gateway device, the data identified by the second time at which the chirp spread-spectrum modulated signal was received at the second gateway device and the second channel frequency.

5. The method of claim 4 further comprising:
sending a fifth message to a third gateway device based on the geographic proximity of the first and second gateway devices to the third gateway device.

6. The method of claim 4 further comprising:
determining, at the second gateway device, whether a chirp spread-spectrum modulated signal was received at the second gateway device at the channel frequency for the chirp spread-spectrum modulated signal and the second time at which the chirp spread-spectrum modulated signal was received at the second gateway device responsive to the fourth message.

7. The method of claim 6 further comprising:
receiving the samples from the first and second gateway devices;
combining the samples from the second gateway device with the samples from the first gateway device to provide a combined signal at the remote server; and
successfully decoding the packet that failed to decode at the first and second gateway devices, using the combined signal at the remote server.

8. The method of claim 7 wherein the combining the samples from the second gateway device with the samples from the first gateway device to provide the combined signal at the remote server further includes applying a phase offset correction to at least one of the samples from the second gateway device and the samples from the first gateway device, wherein the samples comprise inphase/quadrature (I/Q) samples.

9. A method of providing wireless communications comprising:
wirelessly receiving a chirp spread-spectrum modulated signal at a first gateway device, the chirp spread-spectrum modulated signal being transmitted by a remote client device;
demodulating the chirp spread-spectrum modulated signal at the first gateway device to provide demodulated data at the first gateway device;
processing the demodulated data to provide an indication that a decode of a packet including the demodulated data failed; and
combining time adjacent chirps included in the demodulated data from a time interval that includes a chirp spread-spectrum preamble time interval and at least a portion of a chirp spread-spectrum data time interval to provide combined data at the first gateway device.

10. The method of claim 9 further comprising:
transmitting a message from the first gateway device to a remote server responsive to an amplitude of the combined data exceeding a threshold value and the indication that the decode of the packet including the demodulated data failed.

11. A method of providing communications in a wireless chirp spread-spectrum network, the method comprising:
receiving, at a remote server, first and second messages from first and second gateway devices, respectively, indicating that the first and second gateway devices detected first and second potential packets respectively that failed to decode at the first and second gateway devices respectively;
determining whether the first and second potential packets are the same packet based on a similarity between first and second times at which the first and second potential packets were received at the first and second gateway devices and a geographic proximity of the first and second gateway devices to one another to provide a match signal; and
sending third and fourth messages to the first and second gateway devices respectively, responsive to the match signal, the third and fourth messages including requests for inphase/quadrature (I/Q) samples of demodulated data stored in first and second buffer circuits in the first and second gateway devices corresponding to the first and second potential packets respectively identified by the first and second times and first and second channel frequencies on which the first and second potential packets were received.

12. The method of claim 11 further comprising:
wirelessly receiving first and second chirp spread-spectrum modulated signals at the first and second gateway devices respectively, the first and second chirp spread-spectrum modulated signals being transmitted by a remote client device as part of the first and second potential packets respectively;
demodulating the first and second chirp spread-sp

Assignees

• Univ Carnegie Mellon

Inventors

• Dongare Adwait
• Balanuta Artur
• Gadre Akshay
• Iannucci Robert
• Kumar Swarun
• Luong Anh
• Narayanan Revathy
• Rowe Anthony

Classifications

• H04L27/103 Primary

  Chirp modulation (for spread spectrum techniques H04B1/69) · CPC title

• H04B2001/6912

  using chirp · CPC title

• H04L27/364

  Arrangements for overcoming imperfections in the modulator, e.g. quadrature error or unbalanced I and Q levels · CPC title

• H04B1/7102 Primary

  with transform to frequency domain · CPC title

• H04L27/3818

  using coherent demodulation, i.e. using one or more nominally phase synchronous carriers (H04L27/227 and H04L27/389 take precedence) · CPC title