Kramers-Kronig Receiver With Digitally Added Carrier Combined With Digital Resolution Enhancer

Digital phase reconstruction of directly detected minimum (MP) optical signals using the Kramers-Kronig (KK) algorithm has recently drawn attention because its low hardware complexity. Only a single photodiode is required to detect intensity signal and KK relations are used retrieve information. To make sure by MP, carrier tone needs be inserted. In this work, we digitally add at transmitter, omitting need for additional generate tone. However, adding increases quantization noise resulting from digital-to-analog conversion transmitter. A digital resolution enhancer (DRE) can reduce effective transmitter moving outside band. We investigate applicability DRE compensate increased caused insertion. experimentally validate concept demonstrating 64-ary quadrature amplitude modulation (QAM) transmission $25 \,{\mathrm GBd}$, showing that performance 6 bits converter (DAC) system. Furthermore, employing allows reduction DAC system 4 or 5 with limited penalty.