Massachusetts Institute of Technology

Other

King Abdullah University of Science and Technology

Wenhan Dai

Moe Z Win

Mohamed-Slim Alouini

Andrea Conti

Yuan Shen

Stefania Bartoletti

Zehao Yu

Hesham Eisawy

Tianyi Peng

Physical layer key generation provides privacy protection technique suitable for devices with limited computational ability. A key generation algorithm is based on OFDM waveforms. By exploiting the holistic CSI, key generation rate (KGR) is improved significantly. A cross-layer encryption protocol is based on the key generation algorithm and the AES. The secrecy of the encryption is enhanced compared to traditional encryption schemes with one pre-shared key (e.g., WPA2-PSK), even when some generated keys are leaked to the eavesdropper. The results lead to practical and robust applications of physical layer key generation.

Physical layer key generation

An approach to localizing a mobile device takes advantage of the device reporting the order of its neighboring base stations (BSs) according to the received power of the pilot signals. Based on the received BS order, the agent is located within the intersection of corresponding higher-order Voronoi cells. Assuming that the BSs are deployed according to a Poisson point process (PPP) and that signals are subject to log-normal shadowing, the tradeoff between the ALR and the localization error probability can be characterized. It is shown that increasing the number of reported BSs generally reduces the ALR and improves the localization accuracy at the expense of increasing the localization error.

Base station ordering for localization

A ranging system includes an input for receiving a wireless signal and a detector for determining an estimate of a time-of-arrival of the wireless signal at the ranging system. The detector includes a first module for processing the wireless signal according to a non-linear, monotonic transformation to generate a modified signal, a second module for compressing the modified signal according to a linear transformation, resulting in a compressed signal including a number of elements, each element corresponding to a different time segment of the modified signal, and a third module for applying a decision function for determining an output including a first element of the number of elements, corresponding to the time-of-arrival of the wireless signal at the ranging system, applying the decision function, including comparing the elements of the compressed signal to corresponding thresholds of a number of thresholds associated with the number of elements.

Wideband ranging system

A method for localizing one or more devices in an environment make use of repeated allocation of resources for one or more sensor measurements. Each sensor measurement is characterized by the amount of resources allocated to the measurement, by a quality factor, and by direction-dependent characteristics of information that is obtainable from that sensor measurement. Knowledge of a current location of each of the one or more devices determined from past sensor measurements is characterized by a distribution, with each of the distribution containing information about the current location of the device, including the direction-dependent information and the uncertainty of the location. The allocation of resources makes use of the quality factors and direction-dependent characteristics of the sensor measurements, in combination with the distributions characterizing the current location of each of the one or more devices to allocate a variable amount of a resource to each of the one or more sensor measurements.

Variable resource allocation for localization

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Cambridge, MA, United States of America

Wenhan Dai