We numerically study the performance of the displacement based quantum receiver for the discrimination of weak 3- and 4-phase-shift keyed (PSK) coherent state signals. We show that due to the nontrivial asymmetry of the receiver structure, optimization of the prior probability increases the mutual information and achieves sub-shot-noise limit discrimination. Moreover, we estimate the cutoff rate for a 4-PSK signal and confirm that the prior probability optimization shortens the code length for a given decoding error criterion. Such consideration for the asymmetric channel matrix is essential in a study of the compassable quantum receiver.
|Number of pages
|Physics Letters, Section A: General, Atomic and Solid State Physics
|Published - 2013 Nov 22
- Displacement receiver
- Feed forward8Prior probability
ASJC Scopus subject areas
- General Physics and Astronomy