Communication apparatus for transmitting and receiving signals over a fiber-optic waveguide using different frequency bands of light

Communication apparatus for transmitting and receiving signals over a fiber-optic waveguide using different frequency bands of light (Wavelength Division Multiplexing), the apparatus comprising:

• a waveguide serving as a signal transmission medium;
• a plurality of signal couplers for interfacing modulated signals onto the waveguide in separate optical frequency bands;
• a plurality of signal probes forming a probe array at one or more places in the waveguide separated from the signal couplers, such that the originally propagated signals are subject to scrambling and distortion as a result of physical irregularities in the transmission medium;
• and
• a recovery system coupled to the signal probes, to effect recovery and separation of the signals received at the signal probes, using cumulant computations based on cumulants of the fourth or higher even order.