Patent ID: 8103176
Filing Date: 2012-01-24
Classification: H04B

Abstract:
1. A frequency offset compensating apparatus for an optical coherent receiver including a front end processor and a frequency offset estimator, of which said front end processor converts an inputted optical signal into a base band digital electric signal, and said frequency offset estimator estimates a phase offset change introduced by a frequency offset in said base band digital electric signal; said frequency offset compensating apparatus comprising: an M output integrator, for integrating the phase offset change introduced by the frequency offset and estimated by said frequency offset estimator to acquire M inverse numbers of the phase offset introduced by the frequency offset, where M is an integer greater than 1; a series-parallel converting device, for dividing said base band digital electric signal into M sub base band digital electric signals; M complex multipliers, for constructing the corresponding inverse numbers in the M inverse numbers outputted by said M output integrator to be complex numbers, and multiplying them with the corresponding sub base band digital electric signals in the M sub base band digital electric signals converted by said series-parallel converting device; and a parallel-series converting device, for converting the M sub base band digital electric signals multiplied by said complex multipliers into a base band electric signal.