US 12,130,370 B2
Method for measuring distance in wireless communication system and device therefor
Sangrim Lee, Seoul (KR); Hanbyul Seo, Seoul (KR); Sukhyon Yoon, Seoul (KR); Hojae Lee, Seoul (KR); and Hyukjin Chae, Seoul (KR)
Assigned to LG ELECTRONICS INC., Seoul (KR)
Appl. No. 17/053,024
Filed by LG ELECTRONICS INC., Seoul (KR)
PCT Filed Jul. 3, 2018, PCT No. PCT/KR2018/007498
§ 371(c)(1), (2) Date Nov. 4, 2020,
PCT Pub. No. WO2020/009250, PCT Pub. Date Jan. 9, 2020.
Prior Publication US 2021/0239784 A1, Aug. 5, 2021
Int. Cl. H04B 17/00 (2015.01); G01S 5/02 (2010.01); G01S 5/06 (2006.01); H04L 5/00 (2006.01); H04L 27/26 (2006.01); H04W 56/00 (2009.01); H04W 64/00 (2009.01)
CPC G01S 5/0246 (2020.05) [G01S 5/06 (2013.01); H04L 5/0005 (2013.01); H04W 56/005 (2013.01); H04W 56/0065 (2013.01); H04W 64/006 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method of receiving a reference signal for distance measurement by a first wireless device in a wireless communication system, the method comprising:
receiving 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;
obtaining a phase difference between the first and second sinusoidal signals based on a fast Fourier transform (FFT) of the first reference signal;
correcting the phase difference based on the first and second initial phase values; and
transmitting a second reference signal including sinusoidal signals, each having a different angular frequency, for distance measurement and a third reference signal including information about the corrected phase difference to the second wireless device,
wherein the first and second sinusoidal signals are x1(t)=α1*e*j*(w1*t+β1) and x2(t)=α2*ej*(w2*t+β2), respectively, where t denotes a time, α1 denotes an amplitude of the first sinusoidal signal, α2 denotes an amplitude of the second sinusoidal signal, w1 denotes the first angular frequency, w2 denotes the second angular frequency, β1 denotes the first initial phase value, and β2 denotes the second initial phase value.