Utilizing digital TV (DTV) signals, a novel wireless positioning method can be developed for indoors and urban environments, which has potential advantages over GPS. Wireless position based on multi-carrier OFDM (Orthogonal frequency-division multiplexing) DTV signals will have a massive amount of potential users and a broad applicability in the future. This project will investigate new ranging methods by exploiting the property of OFDM signals and fully utilizing the synchronization, channel estimation and diversity gain information demodulated by the receiver. New multipath mitigation methods will also be developed. The positioning method is expected to achieve high positioning accuracy and be reliable in urban and indoor positioning. The new method is considered as an important complement for GPS, and will have huge market potential in the coming years when the DTV system is prepared to be updated. The research methods will provide important reference to other OFDM based communication systems, where a positioning application can also be applied.