2 research outputs found
Quantum Discrimination of Two Noisy Displaced Number States
The quantum discrimination of two non-coherent states draws much attention
recently. In this letter, we first consider the quantum discrimination of two
noiseless displaced number states. Then we derive the Fock representation of
noisy displaced number states and address the problem of discriminating between
two noisy displaced number states. We further prove that the optimal quantum
discrimination of two noisy displaced number states can be achieved by the
Kennedy receiver with threshold detection. Simulation results verify the
theoretical derivations and show that the error probability of on-off keying
modulation using a displaced number state is significantly less than that of
on-off keying modulation using a coherent state with the same average energy.Comment: 12 pages, 4 figure
Optimally Displaced Threshold Detection for Discriminating Binary Coherent States Using Imperfect Devices
Because of the potential applications in quantum information processing
tasks, discrimination of binary coherent states using generalized Kennedy
receiver with maximum a posteriori probability (MAP) detection has attracted
increasing attentions in recent years. In this paper, we analytically study the
performance of the generalized Kennedy receiver having optimally displaced
threshold detection (ODTD) in a realistic situation with noises and imperfect
devices. We first prove that the MAP detection for a generalized Kennedy
receiver is equivalent to a threshold detection in this realistic situation.
Then we analyze the properties of the optimum threshold and the optimum
displacement for ODTD, and propose a heuristic greedy search algorithm to
obtain them. We prove that the ODTD degenerates to the Kennedy receiver with
threshold detection when the signal power is large, and we also clarify the
connection between the generalized Kennedy receiver with threshold detection
and the one-port homodyne detection. Numerical results show that the proposed
heuristic greedy search algorithm can obtain a lower and smoother error
probability than the existing works.Comment: 25 pages, 8 figure