Performance Analysis and Implementation of a New Position Location System Using DTV TxID Watermark

Performance of a new position location system using the transmitter identification (TxID) RF watermark in the digital TV (DTV) signals is analyzed in this paper. Compared to the Global Positioning System (GPS), DTV signals are received from transmitters at relatively short distances, while the broadcast transmitters operate at levels up to a few megawatts of effective radiated power (ERP), which makes the new position location system very robust even inside buildings. Practical receiver implementation issues including non-ideal correlation function and frequency synchronization are analyzed and discussed. New algorithms of removing the bandlimitation effect and frequency synchronization are proposed. Performances of the proposed techniques are evaluated through analysis and Monte Carlo simulations. Possible ways to improve the accuracy of the new position location system are discussed.