Complex optical modulation for real time communication

A system for providing real time optical transport of communications data, the system comprising:

• a first node comprising:
• a Gray encoder that generates first in phase (I) components and first quadrature phase (Q) components from a first serial bit stream of digitized radio frequency (RF) samples;
• a laser transmitter that outputs an optical carrier signal;
• and
• an optical IQ modulator responsive to the Gray encoder, wherein the optical IQ modulator modulates the optical carrier signal based on the first in phase (I) components and the first quadrature phase (Q) components and outputs a complex modulated optical signal to a fiber-optic cable;
• a second node comprising:
• a photo detector coupled to the fiber-optic cable for receiving the complex modulated optical signal,;
• an optical demodulator responsive to the photo detector, the optical demodulator producing second in phase (I) components and second quadrature phase (Q) components in real time as the complex modulated optical signal is received by the photo detector;
• and
• a Gray decoder coupled to the optical demodulator and generating a second serial bit stream of digitized RF samples from the second in phase (I) components and the second quadrature phase (Q) components.

A communications system comprising:

• means for generating first in phase (I) and quadrature phase (Q) components of from a first serial bit stream of digitized radio frequency (RF) samples, wherein the digitized RF samples carry a payload of samples of an RF carrier signal which has been modulated with baseband data;
• means for modulating an optical signal based on the in phase (I) and quadrature phase (Q) components to produce a complex modulated optical signal;
• means for launching the complex modulated optical signal over a fiber optic connection;
• means for demodulating in real time, second in phase (I) and quadrature phase (Q) components from the complex modulated optical signal;
• and
• means for generating a second serial bit stream of digitized RF samples from the second in phase (I) and quadrature phase (Q) components.