Optical receiving apparatus and signal detection method

Abstract

The optical reception device includes: a vector sum estimation unit that estimates a vector sum of symbols in a differentially detected training signal; and a detection unit that detects a period of receipt of at least the training signal on the basis of at least either a comparison result of comparison between an absolute value of the vector sum of symbols in the differentially detected training signal and an absolute value threshold, or a comparison result of comparison between a variation of a phase of the vector sum of symbols in the differentially detected training signal and a predetermined width. The optical reception device may further include: an offset amount estimation unit that estimates a frequency offset amount on the basis of the phase of the vector sum of symbols in the differentially detected training signal when the period of receipt of the differentially detected training signal is detected; and a compensation amount determination unit that determines a compensation amount of a frequency offset on the basis of the frequency offset amount and records the compensation amount in a storage unit.

Dependencies are inferred from the claim text.