Shared LO-based self-coherent 16QAM transmission with PTBC for cost-sensitive metro networks

We propose a cost-effective architecture for > 100-Gb/s metro networks with an 80-km reach, utilizing Alamouti polarization-time block code (PTBC), a self-coherent scheme, and a shared-local oscillator (LO) configuration. The combination of PTBC and the self-coherent scheme enables the use of a single-polarization coherent receiver without carrier recovery algorithms. While conventional self-coherent schemes typically require two fiber strands to transmit a single signal, the proposed shared-LO configuration allows a single LO to serve multiple signal channels, thereby improving fiber utilization efficiency. We experimentally demonstrate the transmission of 120- and 240-Gb/s PTBC 16-QAM signals over 80 km of single-mode fiber. A power budget analysis, based on our experimental results, shows that a single LO can support up to 15 and 7 signal channels for the 120- and 240-Gb/s systems, respectively, assuming a 16-dBm laser output power. • Synergistic integration of PTBC and self-coherent scheme for utilizing cost-effective single-polarization coherent receiver without carrier recovery • Shared local oscillator (LO) architecture to improve fiber utilization and cost effectiveness • Experimental validation of a single-channel 80-km transmission for 120- and 240-Gb/s 16-QAM signals. • Generalized power budget analysis, based on experimental results, projecting that a single LO can support 15 and 7 channels of 120- and 240-Gb/s 16-QAM signals, respectively, assuming a 16-dBm LD power.