Noncoherent detection of coherent optical pulses corrupted by phase noise and additive Gaussian noise.

We present an exact bit-error-rate analysis for digitally modulated lightwave signals corrupted by laser phase noise. In the reception scheme considered, the lightwave signal is heterodyne-detected to produce an electrical bandpass (IF) signal corrupted by both phase noise and additive Gaussian noise. To avoid the problems of coherent demodulation in the presence of phase noise, the IF signal is noncoherently (envelope) detected to produce the baseband pulse stream.