Patent ID: 9001905
Filing Date: 2015-04-07
Classification: G01S,H04L

Abstract:
1. A method, comprising: transforming an orthogonal frequency division multiplexed signal, received at a receiver, in order to determine data from sub-carriers of the received orthogonal frequency division multiplexed signal, wherein the orthogonal frequency division multiplexed signal comprises phase shift keying symbols; comparing data determined from a first sub-carrier of the orthogonal frequency division multiplexed signal with first reference data to determine a first phase difference between a phase of the first sub-carrier when transmitted and a phase of the first sub-carrier when received; comparing data determined from a second sub-carrier of the orthogonal frequency division multiplexed signal with second reference data to determine a second phase difference between a phase of the second sub-carrier when transmitted and a phase of the second sub-carrier when received; and using the determined first phase difference and the determined second phase difference to determine an average distance between the receiver and an origin of the orthogonal frequency division multiplexed signal, wherein the average distance is an average of a first distance for the first sub-carrier of the orthogonal frequency division multiplexed signal and a second distance for the second sub-carrier of the orthogonal frequency division multiplexed signal.