Time-difference-of-arrival and frequency-difference-of-arrival estimation for signals with partially known waveform

In many passive localization applications, the reference waveform of the received electromagnetic signals is partly known. The received signals in such scenarios are formulated by modelling the relationship between the received data and the known reference signal waveform and the parameters of interest, such as time-difference-of-arrival (TDOA) and frequency-difference-of-arrival (FDOA). By exploiting the prior information carried by the known waveform of the reference signal, the negative impact of random noise can be significantly reduced. Following this guideline, a coherent and an incoherent method is proposed to estimate the TDOA and FDOA parameters between two moving receivers. The Cramer-Row lower bound of the TDOA and FDOA estimation accuracy is also analysed. Simulation results show the advantage of the proposed coherent method in TDOA and FDOA estimation precision over its counterparts, which partially demonstrates that effective exploitation of the known signal waveform can largely improve the performance of TDOA and FDOA estimation.