1,653 research outputs found
Enhancing coverage and reducing power consumption in peer-to-peer networks through airborne relaying
Signatures of exciton coupling in paired nanoemitters
An exciton formed by the delocalized electronic excitation of paired nanoemitters is interpreted in terms of the electromagnetic emission of the pair and their mutual coupling with a photodetector. A formulation directly tailored for fluorescence detection is identified, giving results which are strongly dependent on geometry and selection rules. Signature symmetric and antisymmetric combinations are analyzed and their distinctive features identified
Dynamic Interference Mitigation for Generalized Partially Connected Quasi-static MIMO Interference Channel
Recent works on MIMO interference channels have shown that interference
alignment can significantly increase the achievable degrees of freedom (DoF) of
the network. However, most of these works have assumed a fully connected
interference graph. In this paper, we investigate how the partial connectivity
can be exploited to enhance system performance in MIMO interference networks.
We propose a novel interference mitigation scheme which introduces constraints
for the signal subspaces of the precoders and decorrelators to mitigate "many"
interference nulling constraints at a cost of "little" freedoms in precoder and
decorrelator design so as to extend the feasibility region of the interference
alignment scheme. Our analysis shows that the proposed algorithm can
significantly increase system DoF in symmetric partially connected MIMO
interference networks. We also compare the performance of the proposed scheme
with various baselines and show via simulations that the proposed algorithms
could achieve significant gain in the system performance of randomly connected
interference networks.Comment: 30 pages, 10 figures, accepted by IEEE Transaction on Signal
Processin
Efficient Deployment of Multiple Unmanned Aerial Vehicles for Optimal Wireless Coverage
In this paper, the efficient deployment of multiple unmanned aerial vehicles
(UAVs) with directional antennas acting as wireless base stations that provide
coverage for ground users is analyzed. First, the downlink coverage probability
for UAVs as a function of the altitude and the antenna gain is derived. Next,
using circle packing theory, the three-dimensional locations of the UAVs is
determined in a way that the total coverage area is maximized while maximizing
the coverage lifetime of the UAVs. Our results show that, in order to mitigate
interference, the altitude of the UAVs must be properly adjusted based on the
beamwidth of the directional antenna as well as coverage requirements.
Furthermore, the minimum number of UAVs needed to guarantee a target coverage
probability for a given geographical area is determined. Numerical results
evaluate the various tradeoffs involved in various UAV deployment scenarios.Comment: Accepted in the IEEE Communications Letter
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