Method and apparatus for transmitting and receiving coherent optical OFDM

摘要

Disclosed are a method and an apparatus for transmitting and receiving coherent optical OFDM. The apparatus includes: a transmitted OFDM digital signal processing unit outputting an in-phase (I) component digital signal and a quadrature phase (Q) component digital signal; a digital-analog converter converting the in-phase (I)-component digital signal and the quadrature-phase (Q)-component digital signal into an in-phase (I)-component analog signal and a quadrature-phase (Q)-component analog signal, respectively; an adder adding an additional pilot tone signal to each of the in-phase (I)-component analog signal and the quadrature-phase (Q)-component analog signal outputted from the digital-analog converter; and an optical I/Q modulator up-converting the in-phase (I)-component analog signal added with the additional pilot tone signal and the quadrature-phase (Q)-component analog signal added with the additional pilot tone signal to an optical domain to output a coherent optical OFDM signal including the additional pilot tone signal.

主权项

1. An apparatus for transmitting coherent optical OFDM, comprising:
a transmitted OFDM digital signal processing unit outputting an in-phase (I) component digital signal and a quadrature phase (Q) component digital signal; a digital-analog converter converting the in-phase (I)-component digital signal and the quadrature-phase (Q)-component digital signal into an in-phase (I)-component analog signal and a quadrature-phase (Q)-component analog signal, respectively; an adder adding an additional pilot tone signal to each of the in-phase (I) component analog signal and the quadrature-phase (Q)-component analog signal outputted from the digital-analog converter; an optical I/Q modulator up-converting the in-phase (I)-component analog signal added with the additional pilot tone signal and the quadrature-phase (Q)-component analog signal added with the additional pilot tone signal to an optical domain to output a coherent optical OFDM signal including the additional pilot tone signal; wherein an OFDM subcarrier band is above or below a frequency which is centered on a DC component, wherein the additional pilot tone signal is present in a low frequency or high-frequency band which is not overlapped with one or more OFDM data subcarrier bands, and wherein a phase of the additional pilot tone signal is estimated at a receiver and an OFDM data subcarrier is multiplied by a complex conjugate of the estimated phase to compensate a phase noise of the OFDM data subcarrier.