| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical coherent receiver, and a frequency offset estimating apparatus and a frequency offset estimating method for use in the optical coherent receiver. <P>SOLUTION: The optical coherent receiver includes a front end processing section for changing an optical signal into a base band digital electric signal. The frequency offset estimating apparatus includes: a phase offset calculating section, for calculating a phase offset in the base band digital electric signal; a phase offset change calculating section, for calculating a change of the phase offset, namely, a phase offset change, in accordance with the phase offset calculated by the phase offset calculating section; and a loop filtering section 311, for acquiring a weighted average of the phase offset change. <P>COPYRIGHT: (C)2009,JPO&INPIT |
