Systems and methods for determining locations of wireless sensor nodes based on radio frequency communications between the nodes and various RF-enabled devices

An apparatus, comprising:

• a memory for storing instructions;
• one or more 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
• radio frequency (RF) 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 RF circuitry of the apparatus in the wireless network architecture, wherein the one or more processing units of the apparatus are configured to execute instructions to transmit a first RF signal having a first packet to a sensor node, to receive a second RF signal with a second packet from the sensor node, to determine a round trip time estimate of the first and second packets, to determine channel state information (CSI), to calibrate hardware to determine hardware delays of at least one of the apparatus and the sensor node, to apply the hardware delays to the CSI as a linear phase shift to generate corrected CSI, and to divide the corrected CSI by a calibration CSI to remove hardware delays and filter responses of the apparatus and the sensor node, wherein the hardware delays are removed to correct the round trip time estimate of the first and second packets.

A method for localization of wireless nodes comprising:

• transmitting a first RF signal from a first wireless node to a second wireless node;
• receiving a second RF signal with the first wireless node from the second wireless node;
• obtaining channel state information (CSI) for the first and second wireless nodes;
• obtaining internal delays including automatic gain control (AGC) delays from an automatic gain control circuit of RF circuitry and Low-noise amplifier (LNA) delays from a low-noise amplifier circuit of the RF circuitry for each of the first and second wireless nodes;
• removing the AGC delays and the Low-noise amplifier (LNA) delays to correct a coarse time of flight estimate of a first packet sent with the first RF signal and a second packet sent with the second RF signal;
• and
• applying the corrections including the AGC delays and the LNA delays to the CSI as a linear phase shift to generate corrected CSI.