In order to accommodate the demands for the next-generation passive optical network (PON), it is necessary to maximize the transmission capacity and the multiple accesses (MAs) within a single wavelength. However, there is a serious problem that the optical beat interference (OBI) occurs in uplink MA. With optical pulse-division multiplexing (OPDM), the OBI can be reduced simply and effectively; thus, OPDM is a useful optical transmission technique for single-wavelength MA that offers various advantages. To increase the transmission capacity within the limited bandwidth of an optical modulator, we propose a signal-to-noise ratio (SNR) enhancement technique involving receive diversity achieved using the replica inevitably generated in OPDM. The SNR improvement was experimentally verified, via a 20-km optical transmission in OPDM-based single-wavelength MA. The enhanced SNR improves the modulation order and spectral efficiency, and relaxes the requirements of OPDM and the decoding complexity. The proposed replica-based receive diversity can increase the SNR of the uplink signal, reduce the OBI, and guarantees the advantages of OPDM; thus, it is a useful technique for effectively supporting the high data capacity and MA required for the next-generation PON.
Bibliographical noteFunding Information:
Manuscript received April 4, 2018; revised July 2, 2018; accepted August 4, 2018. Date of publication August 15, 2018; date of current version September 12, 2018. This work was supported by the ICT R&D program of MSIP/IITP, South Korea [2014-3-00538]. (Corresponding author: Sang-Kook Han.) The authors are with the Department of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, South Korea (e-mail:, ssun1024@ yonsei.ac.kr; email@example.com; firstname.lastname@example.org; 91hainho@ yonsei.ac.kr; email@example.com).
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics