Performance Analysis of Tdoa/fdoa Estimation for Fm Communication Signals

A study on emitter localization using time difference of arrival (TDOA) and frequency difference of arrival (FDOA) measurements has been increased recently. A TDOA/FDOA system generally consists of two parts: TDOA/FDOA estimation from the unknown received signal (extraction part) and position estimation of the emitter (localization part). Thus, it is important to accurately estimate TDOA and FDOA prior to the localization part. However, in electronic warfare circumstance, due to lack of information of the received signal, the accuracy may varywith chosen parameters and a structure of the receiver. In this paper, we consider the case that an enemy’s emitter transmits an FM-modulated communication signal and phased-locked-loop is no longer available in the receiver because the modulation method is also unknown. To obtain the theoretical limit of the estimation performance in this situation, we analyze the estimation performance of TDOA/FDOA from the received signals corresponding to the bandwidth of the noise reduction filter which is one of the design parameter of the receiver by using Cramer-Rao lower bound (CRLB) and simulations. KeywordsTime Difference of Arrival (TDOA), Frequency Difference of Arrival (FDOA), Electronic Warfare System, Cramer-Rao Lower Bound (CRLB)