Effects of Multipath and Oversampling on Navigation Using Orthogonal Frequency Division Multiplexed Signals of Opportunity

This research exploits the Orthogonal Frequency Division Multiplexed (OFDM) signal for the purpose of navigation. A transmitter and reference receiver, both at known locations, and a mobile receiver at an unknown location were used to conduct simulations of a transmitted OFDM signal in a Rayleigh-distributed multipath environment. The OFDM signal structure was exploited by using the cyclic pre x in a correlation process to nd the rst symbol boundary in each received signal. Statistical features about each symbol is calculated at both receivers and then correlated to nd the di erence in arrival times. The simulations were run for varying levels of multipath, and also for oversampling in an e ort to gain more accurate results by decreasing the sample period.