One-way phase-based high accuracy distance measurement apparatus and algorithm

A method of measuring a distance between two network devices, comprising:

• transmitting, from a first network device, a first range detection signal, the first range detection signal comprises a first frequency (f1) and a second frequency (f2) wherein a phase of the first frequency and the second frequency is constant;
• receiving, at a second network device, the first range detection signal;
• determining, at the second network device, a phase of the first frequency and a phase of the second frequency, referred to as φT1 and φT2, respectively;
• transmitting, from a first network device, a second range detection signal, the second range detection signal comprises a third frequency (f3) and a fourth frequency (f4) wherein a phase of the third frequency and the fourth frequency is constant;
• receiving, at a second network device, the second range detection signal;
• determining, at the second network device, a phase of the third frequency and a phase of the fourth frequency, referred to as φT3 and φT4, respectively;
• and
• calculating a distance between the first network device and the second network device using values of f1, f2, f3, f4, φT1, φT2, φT3, and φT4, where the distance is an inter-frequency group distance measurement.

A system for measuring a distance between two network devices, comprising:

• a first network device, configured to:
• transmit a first range detection signal, the first range detection signal comprises a first frequency (f1) and a second frequency (f2), wherein the first frequency and the second frequency belong to a first frequency group, wherein a frequency group is defined as a set of frequencies generated using a common carrier frequency and wherein a phase of the first frequency and the second frequency is constant;
• and
• a second network device, configured to:
• receive the first range detection signal;
• determine a phase of the first frequency and a phase of the second frequency, referred to as φT1 and φT2, respectively;
• and
• calculate a distance between the first network device and the second network device using values of f1, f2, φT1, and φT2, where the distance is an intra-frequency group distance measurement.