High Tolerance to Coherent Crosstalk of Differential-Phase-Shift-Keying
01 January 2004
It is found experimentally that differential phase-shift-keyed (DPSK) signal with balanced detection has -6 dB higher tolerance to in-band coherent crosstalk than on-off-keyed (OOK) signal. We attribute ths improved crosstalk tolerance of DPSK signal to its 6-dB lowered peak signal power as compared to OOK signal for equal BER in OSNR-limited systems. The impact of signal coherence on the crosstalk tolerance in a 10-Gb/s DPSK system adopting a standard Reed-Solomon forward-error-correction (FEC) is also investigated.