  Time difference of arrival (TDOA) is a widely used technique for localizing a
radio transmitter from the difference in signal arrival times at multiple
receivers. For TDOA to work, the individual receivers must estimate the
respective signal arrival times precisely, which requires sampling the signal
at least double the rate of its highest frequency content, commonly known as
the Nyquist rate. Such sampling is less practical for the millimeter wave band
comprising of frequencies in 30-300 GHz range. In this paper, we propose an
energy detection architecture for accurately estimating the time of arrival
from a single picosecond Gaussian pulse, which enables TDOA localization
without sampling at the receiver. We derive the closed form expression of the
estimated time of arrival and validate it via simulation. We demonstrate that
the proposed sampling-free TDOA can localize millimeter wave transmitters as
accurately as the conventional sampling-based TDOA.

Signal Processing