Progressive interference cancellation for position location in DTV Single Frequency Networks

Positioning based on digital television (DTV) broadcasting systems has attracted considerable attention due to the high transmission power and wide coverage of DTV broadcasting stations in Single Frequency Networks (SFNs). The significant challenge with positioning in SFN is the strong interference from neighboring stations due to the large dynamic range of signals´ strength from different DTV stations. In this paper, a progressive interference cancellation algorithm is proposed to enhance the accuracy of signal detection and time-of-arrival (TOA) estimation of different DTV stations. The interference from stronger (e.g., closer) stations is first reconstructed based on DTV demodulation and channel estimation results, and cancelled from the overall received signal prior to detecting the signal from the desired station. Therefore, the accuracy of TOA estimation of each station is progressively improved. The performance of the positioning system with the proposed interference cancellation is evaluated through computer simulations under different signal propagation scenarios. Simulation results show that high accuracy can be obtained with the proposed positioning system.