Phase and amplitude regeneration of a rectangular 8-QAM in a phase-sensitive amplifier with low-order harmonics.

Applied optics

PubMedID: 28157906

Wang H, Li G, Ji Y. Phase and amplitude regeneration of a rectangular 8-QAM in a phase-sensitive amplifier with low-order harmonics. Appl Opt. 2017;56(3):506-509.
A scheme of regenerating the rectangular 8-QAM with two amplitude and eight phase states is proposed. The scheme can highly improve the efficiency utilizing the fifth and the third harmonics, instead of the seventh harmonic, which is difficult to generate and necessary for the traditional regeneration scheme. By separating the regeneration process into two steps, the scheme can also realize the separation of the different level states and the reduction of the amplitude and phase noise. The improvement of the error vector magnitude and the variances of phase and amplitude show the effectiveness of the scheme for the rectangular 8-QAM signal regeneration.