| 摘要 |
<p>In this polarization demultiplexing optical communication system, in order to reduce the effect of phase deviation noise so as to increase the accuracy of an estimate of the amount of phase compensation, this signal processing circuit is provided with: optical frequency deviation estimation means for estimating a frequency deviation which indicates a difference between the frequency of an optical carrier, which is included in signal data corresponding to polarization generated by mixing a plurality of optical carriers having phase-modulated separable polarization with local light, and the frequency of the local light, in order to output the frequency deviation as an estimate; optical frequency deviation compensation amount analysis means which, on the basis of a plurality of estimates, calculates a frequency compensation amount which imparts a phase rotation to the signal data so as to reduce the frequency deviation; optical frequency deviation compensation means which imparts phase rotation corresponding to the amount of frequency compensation to the signal data; optical phase deviation estimation means for estimating phase deviation indicating phase difference between the optical carrier included in the signal data which has been input and the local light; and optical phase deviation compensation means which imparts phase rotation corresponding to the phase deviation to the signal data.</p> |
