Systems and methods for precise radio frequency localization in the presence of multiple communication paths
Systems and methods for determining locations of wireless nodes in a network architecture are disclosed herein. In one example, an asynchronous system includes a first wireless node having a wireless device with one or more processing units and RF circuitry for transmitting and receiving communications in the wireless network architecture including a first RF signal having a first packet. The system also includes a second wireless node having a wireless device with a transmitter and a receiver to enable bi-directional communications with the first wireless node in the wireless network architecture including a second RF signal with a second packet. The first wireless node determines a time of flight estimate for localization based on a time estimate of round trip time of the first and second packets and a time estimate that is based on channel sense information of the first and second wireless nodes.
1. An apparatus, comprising:
a memory for storing instructions;
a set of processing units to execute instructions for controlling a plurality of sensor nodes in a wireless network architecture and determining locations of the plurality of sensor nodes; and
a radio frequency ( ) circuitry to transmit communications to and receive communications from the plurality of sensor nodes each having a wireless device with a transmitter and a receiver to enable bi-directional communications with the radio frequency circuitry of the apparatus in the wireless network architecture, wherein the set of processing units of the apparatus are configured to execute instructions to:
calibrate an automatic gain control stage of the radio frequency circuitry by measuring a delay of the automatic gain control stage as a function of gain; and
determine a time of flight estimate for communications between the apparatus and a sensor node based on the calibration of the automatic gain control stage.
2. The apparatus of claim 1 , wherein the set of processing units of the apparatus are further configured to:
execute instructions to detect a deviation between the delay and a baseline delay of the automatic gain control stage; and
correct a timing of the time of flight estimate in response to detecting the deviation.
3. The apparatus of claim 1 , wherein the set of processing units of the apparatus are configured to execute instructions to calibrate a filter stage by measuring a delay of the filter stage.
4. The apparatus of claim 3 , wherein the set of processing units of the apparatus are further configured to execute instructions to:
detect a deviation between the filter delay and a baseline filter delay; and
correct a timing of the time of flight estimate in response to detecting the deviation.
5. The apparatus of claim 1 , wherein the apparatus comprises a hub.
6. The apparatus of claim 1 , wherein the automatic gain control stage comprises a closed-loop feedback regulating circuit that provides a controlled signal amplitude for an output despite variation of an amplitude for an input.
7. A method for calibrating an automatic gain control stage of a radio frequency ( ) circuitry of a wireless device, the method comprising:
initializing a wireless network architecture having a plurality of sensor nodes;
calibrating the automatic gain control stage of the radio frequency circuitry of the wireless device by measuring a delay of the automatic gain control stage as a function of gain; and
determining a time of flight estimate for communications between the wireless device and a sensor node of the wireless network architecture based on calibration of the automatic gain control stage of the radio frequency circuitry of the wireless device.
8. The method of claim 7 , wherein calibrating the automatic gain control stage of the radio frequency circuitry of the wireless device comprises:
detecting a deviation between the delay and a baseline delay of the automatic gain control stage; and
correcting a timing of the time of flight estimate in response to detecting the deviation.
9. The method of claim 7 , wherein the wireless device comprises a hub.
10. An apparatus, comprising:
a memory for storing a set of instructions;
a set of processing units configured to
execute instructions for controlling a plurality of sensor nodes in a wireless network architecture and determining locations of the plurality of sensor nodes; and
a radio frequency circuitry configured to transmit communications to and receive communications from the plurality of sensor nodes each having a wireless device with a transmitter and a receiver to enable bi-directional communications with the radio frequency circuitry of the apparatus in the wireless network architecture, wherein the set of processing units of the apparatus are configured to execute instructions to:
calibrate an automatic gain control stage of the radio frequency circuitry; and
determine a time of flight estimate for communications between the apparatus and a sensor node based on the calibration of the automatic gain control stage; and
wherein the set of processing units are further configured to execute the set of instructions to:
measure a filter delay of a filter stage;
detect a deviation between the filter delay and a baseline filter delay; and
correct a timing of the time of flight estimate in response to detecting the deviation.
11. A method for calibrating a filter stage of a radio frequency circuitry of a wireless device, the method comprising:
initializing a wireless network architecture having a plurality of sensor nodes;
calibrating the filter stage of the radio frequency circuitry of the wireless device by measuring a filter delay of the filter stage;
determining a time of flight estimate for communications between the wireless device and a sensor node of the wireless network architecture based on the calibration of the filter stage of the radio frequency circuitry of the wireless device;
detecting a deviation between the filter delay and a baseline filter delay; and
correcting a timing of the time of flight estimate in response to detecting the deviation.