Software-Defined Radio LTE Positioning Receiver Towards Future Hybrid Localization Systems Jos´ e A. del Peral-Rosado * , Jos´ e A. L´ opez-Salcedo, Gonzalo Seco-Granados, Department of Telecommunications and System Engineering, Universitat Aut`onoma de Barcelona (UAB), 08193 Cerdanyola del Vall` es, Spain Francesca Zanier, Paolo Crosta, Rigas Ioannides, and Massimo Crisci Radio Navigation Systems and Techniques Section, European Space Agency/ESTEC, 2201 AZ Noordwijk, The Netherlands The appropriate positioning characteristics and fast deployment of Long Term Evolution (LTE) systems makes this technology a promising candidate towards future satellite and terrestrial hybrid scenario. Nevertheless, further studies on the achievable LTE position- ing capabilities are still necessary for commercial or realistic network deployments. This paper describes a tool that provides standalone localization in LTE networks. The tool is a software-defined radio (SDR) receiver working at the LTE physical layer, performing acquisition, tracking and positioning. The SDR LTE positioning receiver is validated in a static scenario, showing position errors below three meters in the absence of multipath for a signal bandwidth of 1.08 MHz. Nomenclature 3GPP 3 rd Generation Partnership Project AWGN Additive White Gaussian Noise BS Base Station CFO Carrier Frequency Offset CP Cyclic Prefix CRS Cell-specific Reference Signal DLL Delay Lock Loop E-SMLC Evolved Serving Mobile Location Centre E-UTRA Evolved Universal Terrestrial Radio Access EARFCN E-UTRA Absolute Radio Frequency Channel Number FDD Frequency Division Duplexing FFT Fast Fourier Transform GNSS Global Navigation Satellite Systems LPP LTE Positioning Protocol LTE Long Term Evolution ML Maximum Likelihood NDA Non-Data-Aided OFDM Orthogonal Frequency Division Multiplexing OTDoA Observed Time Difference Of Arrival PBCH Physical Broadcast CHannel PCFICH Physical Control Format Indicator CHannel PDCCH Physical Downlink Control CHannel PDSCH Physical Downlink Shared CHannel * Emails: {JoseAntonio.DelPeral, Jose.Salcedo, Gonzalo.Seco}@uab.cat, {Francesca.Zanier, Paolo.Crosta, Rigas.Ioannides, Massimo.Crisci}@esa.int; Corresponding author phone: +34 93 581 3843 1 of 11 American Institute of Aeronautics and Astronautics