Time delay tracking for positioning in DTV networks

This paper studies the wireless positioning method using digital TV (DTV) signals with orthogonal frequency division multiplex (OFDM) modulation. A novel pseudo range estimation method is proposed, which utilizes the synchronization modules in the data demodulation as the signal acquisition for the coarse time delay estimation and introduces a data-directed delay tracking mechanism for the fine time delay tracking. In the time delay tracking modules, the demodulated data is used to produce the copies of the transmitted OFDM signals and applied into the delay locked loop (DLL) to track the time delay of the received OFDM signals. Simulation results show the effectiveness of the method.