Optical data transmitting apparatus and method
AssigneeNEC Corporation
InventorYutaka Yano
Life of this patent
Estimating the term…
Abstract
An optical data transmitting apparatus and method allows data transmission over a distance that surpasses a limit, which has been imposed due to group velocity dispersion (GVD) and self phase modulation (SPM) effect within optical fiber. This has been accomplished by allocating trinal duobinary symbols to optical 1, P, −1 symbols. These optical symbols have the same intensity, +1 and −1 symbols have inverted optical phases each other, and orthogonally polarized each other between ±1 and P symbols. At the receiver, conventional polarization shift keying receiver can be used to restore original binary data stream.
Claims7
An optical data transmitting apparatus comprising:
- a carrier light source;
- means for separating a binary input data signal into a first data signal and a second data signal;
- a polarization modulator that polarizes said carrier light source in response to said first data signal to obtain a polarization modulated light;
- a pre-coder that encodes said second data signal to output a coded second data signal;
- and
- a phase modulator that phase shifts said polarization modulated light in response to said coded second data signal.
An optical data transmitting method comprising the steps of:
- separating a binary input data signal into first data signal and second data signal;
- polarization modulating a carrier light in response to said first data signal to obtain a polarization modulated light;
- transforming said second data signal into a code transformed second data signal;
- and
- phase modulating said polarization modulated light in response to said code transformed second signal.
Dependencies are inferred from the claim text.