Method for measuring distance in wireless communication system and device therefor

A method of transmitting a reference signal for distance measurement to a first wireless device by a second wireless device in a wireless communication system, the method comprising:

• transmitting a first reference signal including a first sinusoidal signal and a second sinusoidal signal to the first wireless device, wherein the first sinusoidal signal has a first angular frequency and a first initial phase value, and wherein the second sinusoidal signal has a second angular frequency and a second initial phase value;
• receiving a second reference signal for distance measurement and a third reference signal including information about a corrected phase difference from the first wireless device;
• and
• estimating a distance between the first and second wireless devices based on the information about the corrected phase difference,
• wherein the information about the corrected phase difference includes a phase difference between the first and second sinusoidal signals corrected by the first wireless device in consideration of the first and second initial phase values after receipt of the first reference signal.

A first wireless device for receiving a reference signal for distance measurement in a wireless communication system, the first wireless device comprising:

• a transceiver;
• and
• a processor configured to:
• control the transceiver to receive a first reference signal including a first sinusoidal signal and a second sinusoidal signal from a second wireless device, wherein the first sinusoidal signal has a first angular frequency and a first initial phase value, and wherein the second sinusoidal signal has a second angular frequency and a second initial phase value;
• obtain a phase difference between the first and second sinusoidal signals based on a fast Fourier transform (FFT) of the first reference signal;
• correct the phase difference based on the first and second initial phase values;
• and
• transmit a second reference signal for distance measurement and a third reference signal including information about the corrected phase difference to the second wireless device.