A novel subspace-based joint TDOA and FDOA estimation using chirp signals for mobile multipath environment

In this paper, we propose subspace-based joint time difference of arrival (TDOA) and frequency difference of arrival (FDOA) estimation method using chirp signals for mobile multipath environments. The conventional methods for TDOA and FDOA estimation has been developed based on the signal model derived in a single path. However, single path channel model is not preferred in algorithm development for TDOA since it is not a realistic channel. Therefore, the conventional algorithms which have been developed based on the single path channel model cannot be easily extended to multipath channel. Thus, we propose a new TDOA and FDOA estimation technique based on multipath channel model. To achieve high accuracy, the subspace-based parameter estimation technique ESPRIT is used with some modification for a joint estimation of TDOA and FDOA. The proposed technique shows superior performance in multipath decomposition. Using the decomposition capability, the TDOA and FDOA for the direct path (the first arrival path) can be estimated well in spite of the interference caused by the other received paths. The performance of the proposed joint TDOA and FDOA estimation technique is evaluated through computer simulations under mobile multipath channel and compared with those of conventional methods.