Aritrik Ghosh

About Me

Hi, I am Aritrik Ghosh, I am a 3rd year Ph.D in Computer Science at the University of Maryland College Park. I am working at iCoSMoS Lab with Prof. Nirupam Roy.

Research interests: Wireless Localization, Quantum Sensing , E.M. Sensing.

Lab : IRB 3245

Office : IRB 2104

Publications

[Sensys 2024] Litefoot: Ultra-low-power localization using ambient cellular signals

Abstract— In this paper, we introduce a low-power wide-area cellular localization system, called LiTEfoot. The core architecture of the radio carefully applies non-linear transform of the entire cellular spectrum to obtain a systematic superimposition of the synchronization signals at the baseband. The system develops methods to simultaneously identify all the base stations that are active at any cellular band from the transformed signal. The radio front end uses a simple envelop detector to realize the non-linear transformation. We build on this low-power radio to implement a self-localization system leveraging ambient 4G-LTE signals. We show that the core system can also be extended to other cellular technologies like 5G-NR and NB-IoT. The prototype achieves a median localization error of 22 meters in urban areas and 50 meters in rural areas. It can sense a 3GHz wideband LTE spectrum in 10ms using non-linear intermodulation while consuming 0.9 mJ of energy for a PCB-based implementation and 40 μJ for CMOS simulation. In other words, LiTEfoot tags can last for 11 years on a coin cell while continuously estimating location every 5 seconds. We believe that LiTEfoot will have widespread implications in city-scale asset tracking and other location-based services. The radio architecture can be useful beyond low-power self-localization and can find application in synchronization and communication on battery-less platforms.

3666025.3699356.pdf

[DYSPAN 2021] A Gaussian Process Based Technique of Efficient Sensor Selection for Transmitter Localization

Abstract :- Spectrum monitoring via crowdsourcing is a technique that promises to enable opportunistic spectrum access. Crowdsourcing aims to provide incentives to users to deploy a large number of cheap but potentially noisy sensors. The sensors all send their data to a fusion center, where typically some algorithms are used to remove the noise from the data. Such crowdsourced monitoring of spectrum has been shown to be feasible in practice in multiple studies. One of the key goals of such monitoring is to identify any users that are violating the protocols of accessing spectrum. While a number of crowdsourcing techniques to identify such violations have been proposed, a key challenge that remains is to minimize the cost of data consumption and energy of running the sensors. In this work, we propose sequential probing of sensors to accurately localize/identify such transmitters. We formulate this as a Gaussian Process multi-armed bandit problem, and use a widely known solution technique called Upper Confidence Bound to solve it. We next observe that such sequential probing incurs additional latency, and use batched selection of sensors in few rounds to reduce latency. We show that instead of naively selecting sensors in parallel batches, an intelligent technique of selecting sensors called Gaussian Process Adaptive Upper Confidence Bound (GP-AUCB) can lead to selection of sensors that can lead to more accurate localization. Finally, we show the tradeoff between accuracy of localization, latency incurred and number of selected sensors via simulations.

Dyspan21.pdf

[InCAP 2021] SIW-fed Metallic Cap Loaded Cylindrical DRA Array Antenna for 5g mm-wave Application

Abstract— In this article, a cylindrical dielectric resonator array antenna fed with a SIW (substrate integrated waveguide) based Wilkinson power divider network is proposed for 5G mm wave application. The design consists of four cylindrical dielectric resonator antennas (DRAs) that are mounted on the top of the four slots, two on each arm of a 1:2 Wilkinson power divider. Ansys HFSS simulation results confirm that the proposed array operates at 28 GHz with a bandwidth of 330 MHz with good monopole type radiation and a peak gain of 9.9 dBi.

APS_2894.pdf

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