  This paper presents a novel antenna configuration to measure directions of
multiple signal sources at the receiver in a THz mobile network via a single
channel measurement. Directional communication is an intrinsic attribute of THz
wireless networks and the knowledge of direction should be harvested
continuously to maintain link quality. Direction discovery can potentially
impose an immense burden on the network that limits its communication capacity
exceedingly. To utterly mitigate direction discovery overhead, we propose a
novel technique called spectrum shaping capable of measuring direction, power,
and relative distance of propagation paths via a single measurement. We
demonstrate that the proposed technique is also able to measure the transmitter
antenna orientation. We evaluate the performance of the proposed design in
several scenarios and show that the introduced technique performs similar to a
large array of antennas while attaining a much simpler hardware architecture.
Results show that the spectrum shaping with only two antennas placed 0.5 mm, 5
mm, and 1 cm apart performs direction of arrival estimation similar to a much
more complex uniform linear array equipped with 7, 60, and 120 antennas,
respectively.
