상세정보
학술지
Demonstration of 200 Gbps PAM-4 transmission in a limited-bandwidth system using a two-tap THP with nonlinearity compensator
- 발행일
- 202301
- 출처
- Optical Fiber Technology, v.75, pp.1-8
- ISSN
- 1068-5200
- 출판사
- Elsevier
- 협약과제
- 21HH5900, [전문연구실/통합과제] 광 클라우드 네트워킹 핵심기술 개발 , 이준기
- 초록
- In this paper, we have proposed a digital signal processing (DSP) method for a 200 Gbps pulse-amplitude modulation level-4 (PAM-4) transmission in a bandwidth-limited system. To mitigate inter-symbol interferences (ISI) in the system and reduce the propagation of errors in the receiver, the Tomlinson-Harashima precoding (THP) technique was applied to the transmitter. For simplicity, the number of THP taps was limited to two (i.e., one coefficient to be optimized); the residual ISI resulting from the short tap was compensated for with a decision feedback equalizer (DFE). The performance of the proposed DSP was analyzed via experiments and simulations. Compared to conventional DSP techniques (such as DFE and the maximum likelihood sequence estimation (MLSE) without THP), the proposed DSP performs better within the limited-bandwidth region. As a result, the soft-decision forward error correction (SD-FEC) threshold (of 2 × 10?닋2) was satisfied even when the bandwidth fell to below 35% of the baud rate. To enhance this performance, post-filter and MLSE were additionally applied, after which its performance was investigated. In addition, the nonlinear characteristics of the components were alleviated by applying a pre-distortion technique to the THP using look-up tables; this further enhanced performance, lowering the SD-FEC threshold's bandwidth to 32% of the baud rate.
- KSP 제안 키워드
- 4-level pulse amplitude modulation(PAM-4), Baud rate, Digital Signal Processing, Experiments and simulations, Forward error correction(FEC), Maximum likelihood sequence estimation(MLSE), Nonlinear characteristics, Post-filter, Pre-distortion, Residual ISI, SD-FEC
본 저작물은 크리에이티브 커먼즈 저작자 표시 - 비영리 - 변경금지 (CC BY NC ND) 조건에 따라 이용할 수 있습니다.
