Diversity receiver for mitigating the effects of fiber dispersion by separate detection of the two transmitted sidebands

A method for generating, transmitting, and receiving an optical double sideband signal, comprising the steps of:

• generating an optical carrier;
• sending said optical carrier to a modulator;
• concurrently encoding an input data signal to produce an encoded data signal;
• intensity modulating said fine encoded data signal to produce an optical double sideband signal;
• transmitting said optical double sideband signal over a fiber link;
• splitting the received optical double sideband signal into an upper sideband signal and a lower sideband signal;
• photodetecting and adaptively equalizing said upper sideband;
• photodetecting and adaptively equalizing said lower sideband;
• compensating said photodetected and adaptively equalized upper sideband signal for chromatic dispersion and polarization mode dispersion;
• compensating said photodetected and adaptively equalized lower sideband signal for chromatic dispersion and polarization mode dispersion;
• and
• combining said dispersion compensated upper sideband signal with said dispersion compensated lower sideband signal;
• detecting a bit error rate of the resulting combined signal;
• and
• adjusting the adaptive equalizing according to the bit error rate.

A method of receiving an optical double sideband signal, comprising the steps of:

• receiving an optical double sideband signal;
• splitting said received optical double sideband signal using a splitter into two branches;
• concurrently processing the resulting two branches by applying a filter to each branch to produce a filtered upper sideband signal and a filtered lower sideband signal;
• concurrently applying a photodetector to said filtered upper sideband signal and to said filtered lower sideband signal to produce a photodetected upper sideband signal and a photodetected lower sideband signal;
• adaptively equalizing said upper sideband signal;
• adaptively equalizing said lower sideband signal;
• compensating said photodetected and adaptively equalized upper sideband signal for chromatic dispersion and polarization mode dispersion;
• compensating said photodetected and adaptively equalized lower sideband signal for chromatic dispersion and polarization mode dispersion;
• and
• combining said dispersion compensated upper sideband signal and said dispersion compensated lower sideband signal using a combiner to produce an output signal;
• detecting a bit error rate of the resulting combined signal:
• and
• adjusting the adaptive equalizing according to the bit error rate.

A method of generating, transmitting and receiving an optical double sideband signal comprising the steps of:

• generating an optical carrier;
• sending said optical carrier to a modulator;
• concurrently encoding an input data signal to produce an encoded data signal;
• intensity modulating said line encoded data signal to produce an optical double sideband signal;
• transmitting said optical double sideband signal over a fiber link;
• receiving said optical double sideband signal;
• splitting said received optical double sideband signal using a splitter into two branches;
• concurrently processing the resulting two branches by applying a filter to each branch to produce a filtered upper sideband signal and a filtered lower sideband signal;
• concurrently applying a photodetector to said filtered upper sideband signal and to said filtered lower sideband signal to produce a photodetected upper sideband signal and a photodetected lower sideband signal;
• adaptively equalizing said upper sideband signal;
• adaptively equalizing said lower sideband signal;
• compensating said photodetected and adaptively equalized upper sideband signal for chromatic dispersion and polarization mode dispersion;
• compensating said photodetected and adaptively equalized lower sideband signal for chromatic dispersion and polarization mode dispersion;
• and
• combining said dispersion compensated upper sideband signal and said dispersion compensated lower sideband signal using a combiner to produce an output signal;
• detecting a bit error rate of the resulting combined signal;
• and
• adjusting the adaptive equalizing according to the bit error rate.