Signal recovery based on optoelectronic reservoir computing for high speed fiber communication

Signal recovery effects of a channel equalization method based on optoelectronic reservoir computing (RC) are investigated for actual high speed optical fiber communication systems. The RC is implemented numerically by using a Mach-Zehnder intensity modulator with an optoelectronic delay feedback loop. Two optical communication systems with different transmission distances and receivers based on 25G-class optics are built in-lab. 50-Gb/s non-return-to-zero (NRZ) and four-level pulse amplitude modulation (PAM4) signals transmitted by the two systems are recovered by using optoelectronic RC and different combinations of feed forward equalizer (FFE) with decision feedback equalizer (DFE) and maximum likelihood sequence estimation (MLSE), respectively. Under the same conditions, optoelectronic RC is better than FFE&DFE, and far superior to FFE&MLSE in the equalization performances. When the receiver is a positive-intrinsic-negative or avalanche photodiode, for the NRZ signal, compared with 45-tap FFE and 9-tap DFE, the sensitivity is increased by similar to 3.2/3.4 dB; for the PAM4 signal, the sensitivity is improved by similar to 4.9/4.6 dB compared with 123-tap FFE and 9-tap DFE. These experimental results show that the optoelectronic RC has excellent performances for signal recovery of different modulation formats and transmission systems.

Automated summary

This study investigates the signal recovery effects of a channel equalization method based on optoelectronic reservoir computing for high-speed optical fiber communication systems. The experimental results show that optoelectronic reservoir computing performs excellently in signal recovery for different modulation formats and transmission systems.