306,467 research outputs found
Joint Computation and Communication Cooperation for Mobile Edge Computing
This paper proposes a novel joint computation and communication cooperation
approach in mobile edge computing (MEC) systems, which enables user cooperation
in both computation and communication for improving the MEC performance. In
particular, we consider a basic three-node MEC system that consists of a user
node, a helper node, and an access point (AP) node attached with an MEC server.
We focus on the user's latency-constrained computation over a finite block, and
develop a four-slot protocol for implementing the joint computation and
communication cooperation. Under this setup, we jointly optimize the
computation and communication resource allocation at both the user and the
helper, so as to minimize their total energy consumption subject to the user's
computation latency constraint. We provide the optimal solution to this
problem. Numerical results show that the proposed joint cooperation approach
significantly improves the computation capacity and the energy efficiency at
the user and helper nodes, as compared to other benchmark schemes without such
a joint design.Comment: 8 pages, 4 figure
Towards deterministic optical quantum computation with coherently driven atomic ensembles
Scalable and efficient quantum computation with photonic qubits requires (i)
deterministic sources of single-photons, (ii) giant nonlinearities capable of
entangling pairs of photons, and (iii) reliable single-photon detectors. In
addition, an optical quantum computer would need a robust reversible photon
storage devise. Here we discuss several related techniques, based on the
coherent manipulation of atomic ensembles in the regime of electromagnetically
induced transparency, that are capable of implementing all of the above
prerequisites for deterministic optical quantum computation with single
photons.Comment: 11 pages, 7 figure
Molecular Quantum Computing by an Optimal Control Algorithm for Unitary Transformations
Quantum computation is based on implementing selected unitary transformations
which represent algorithms. A generalized optimal control theory is used to
find the driving field that generates a prespecified unitary transformation.
The approach is illustrated in the implementation of one and two qubits gates
in model molecular systems.Comment: 10 pages, 2 figure
Threshold Error Penalty for Fault Tolerant Computation with Nearest Neighbour Communication
The error threshold for fault tolerant quantum computation with concatenated
encoding of qubits is penalized by internal communication overhead. Many
quantum computation proposals rely on nearest-neighbour communication, which
requires excess gate operations. For a qubit stripe with a width of L+1
physical qubits implementing L levels of concatenation, we find that the error
threshold of 2.1x10^-5 without any communication burden is reduced to 1.2x10^-7
when gate errors are the dominant source of error. This ~175X penalty in error
threshold translates to an ~13X penalty in the amplitude and timing of gate
operation control pulses.Comment: minor correctio
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