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arXiv · 2109.11079

Ultimate accuracy limit of quantum pulse-compression ranging

Quntao Zhuang·Jeffrey H. Shapiro
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Abstract

Radars use time-of-flight measurement to infer the range to a distant target from its return's roundtrip range delay. They typically transmit a high time-bandwidth product waveform and use pulse-compression reception to simultaneously achieve satisfactory range resolution and range accuracy under a peak transmitted-power constraint. Despite the many proposals for quantum radar, none have delineated the ultimate quantum limit on ranging accuracy. We derive that limit through continuous-time quantum analysis and show that quantum illumination (QI) ranging -- a quantum pulse-compression radar that exploits the entanglement between a high time-bandwidth product transmitted signal pulse and and a high time-bandwidth product retained idler pulse -- achieves that limit. We also show that QI ranging offers mean-squared range-delay accuracy that can be 10's of dB better than a classical pulse-compression radar's of the same pulse bandwidth and transmitted energy.

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Quntao Zhuang, Jeffrey H. Shapiro. 2021-09-22. Ultimate accuracy limit of quantum pulse-compression ranging. https://doi.org/10.1103/physrevlett.128.010501

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