Multicarrier Technique-Based Super-Resolution TDOA Estimation

This letter presents an original solution to extract the time difference of arrival (TDOA) from the baseband channel estimation of a multicarrier communication, i.e. orthogonal frequency division multiplexing (OFDM). Considering a particular Multiple-Input Single-Output (MISO) configuration, the delay between two direct paths impacts, by means of amplitude modulation, the received spectrum. With an appropriate demodulation, one can then estimate the TDOA even with presence of multipath. This method exhibits superior resolution compared to conventional time domain approaches dealing with inter-correlation function or spectral domain involving Fourier Transform. For example, it allows estimating TDOA of about 2 ns when using a null-to-null bandwidth of 100 MHz. Such approach can be useful for several applications needing accurate positioning for indoor environment.