32.1 Gbit/s InverseRZ-ASK-DQPSK Modulation with Low Implementation Penalty

32.1 Gbit/s InverseRZ-ASK-DQPSK is experimentally investigated using a new InverseRZ generation method. We demonstrate <1 dB upgrade penalty from 21.4 Gbit/s RZ-DQPSK, and <2 dB transmission penalty after one 75 km fibre span.