Wireless Positioning Using TDS-OFDM Signals in Single-Frequency Networks

Wireless positioning using digital television (DTV) signals is a promising complementary to global positioning system due to high transmission power and wide coverage of DTV transmitters. Without changing the current infrastructure of Chinese DTV broadcasting network, this paper proposes a positioning scheme using time-domain synchronous (TDS) orthogonal frequency division multiplexing (OFDM) signals in single-frequency networks. The transmission parameter signaling (TPS) embedded in the TDS-OFDM signals is time-division multiplexed as orthogonal frequency-domain pilots, and then the time-domain pseudorandom noise sequence and the frequency-domain TPS are jointly utilized for accurate time of arrival (TOA) estimation for each transmitter. The theoretical bound of the TOA estimation accuracy is also derived. The proposed wireless positioning scheme has no impact on the normal TV program reception. Simulation results show that the positioning accuracy of less than 1 m can be achieved in SFN scenarios. The idea of time-frequency joint positioning can also be applied to other OFDM-based wireless systems.