Localization and Fingerprint of Radio Signals Employing a Multichannel Photonic Analog-to-Digital Converter

[EN] The fingerprint and localization of radio signals employing a multichannel photonic analog-to-digital converter (ADC) is proposed, analyzed, and demonstrated in a laboratory experiment. The photonic ADC detects the radio signals with high sensitivity in a large bandwidth without down-conversion stages. This is of special interest when processing emerging low-power wireless standards like ultra-wideband (UWB) radio. The optical processing in the multichannel photonic ADC is tailored for the localization and fingerprint of generic radio transmitters when orthogonal-frequency division multiplexing (OFDM) modulation is employed in the transmission. The photonic ADC includes engineered optical and electrical amplification. The experimental work demonstrates that detection of radio signals with -65 dBm power with signal-to-noise ratio better than 20 dB is feasible, which is in good accordance with the theoretical analysis. The multichannel photonic ADC comprises five optical channels which are precisely time-aligned in optical domain achieving 0.23-m spatial resolution (median) in the localization of radio transmitters. The experimental work also demonstrates that photonic-ADC processing is adequate for OFDM-based UWB radio-signal fingerprint including estimation of the average power, frequency band of operation, and time-frequency hopping pattern if applicable. UWB transmitter localization has been experimentally demonstrated with 0.4-m error. This work was supported in part by the European 7th Framework Program Project UCELLS FP7-IST-216785. The work of M. Morant was supported by Spain FPU MEC under Grant AP2007-01413. Llorente, R.; Morant, M.; Puche, JF.; Romme, J.; Amiot, N.; Uguen, B.; Duplicy, J. (2010). Localization and Fingerprint of Radio Signals Employing a Multichannel Photonic Analog-to-Digital Converter. IEEE Transactions on Microwave Theory and Techniques. 58(11):3304-3311. https://doi.org/10.1109/TMTT.2010.2076730