Proposal to Achieve 1 Tb/s per Wavelength Transmission Using Three-Dimensional LDPC-Coded Modulation

We propose a three-dimensional (3-D) low-density parity check (LDPC)-coded modulation scheme that enables optical transmission beyond 320 Gb/s in aggregate rate using currently available commercial components operating at 40 giga-symbols/s. The proposed scheme introduces significant performance improvement of up to 4.1 dB at a bit-error ratio of 10^-9 over the corresponding two-dimensional scheme. In addition, by using LDPC-coded 1024-3D-constellation it is possible, at least in theory, to achieve beyond a total of 1-Tb/s transmission using transmission equipment operating at 100 giga-symbols/s, once it reaches the maturity of 40-Gb/s systems.     

Beyond 240 Gb/s per Wavelength Optical Transmission Using Coded Hybrid Subcarrier/Amplitude/Phase/Polarization Modulation

In this letter, we propose a low-density parity-check coded hybrid subcarrier/amplitude/phase/polarization (H-SAPP) modulation scheme suitable to achieve a 240-Gb/s single-channel transmission rate over optical channels. The proposed scheme doubles the aggregate transmission rate achievable by eight-quadrature amplitude modulation while providing 2-dB optical signal-to-noise ratio performance improvement at a bit-error-ratio (BER) of $10^{-6}$ . Moreover, H-SAPP can increase the aggregate rate of the hybrid amplitude/phase/polarization scheme while maintaining the BER performance intact.      

Proposal for Beyond 100-Gb/s Optical Transmission Based on Bit-Interleaved LDPC-Coded Modulation

An iterative bandwidth-efficient coded modulation scheme based on bit-interleaving low-density parity-check (LDPC) codes, and M-ary differential phase-shift keying is proposed. A bit-interleaved LDPC-coded scheme, carrying 3 bits/symbol, provides the coding gain of 8.3 dB at a bit-error rate (BER) of 10^-7. The expected coding gain at BER of 10^-12 is 12.8 dB. Possible applications include 100G Ethernet, and high-speed (>100 Gb/s) long-haul transmission     

基于10 Gb/s传输链路的40 Gb/s光传输实验研究

基于中国自然科学基金网(NSFCNet)的400 km×10 Gb/s光传输链路实现了40 Gb/s光传输,没有出现误码率(BER)平台,说明在常规的中短距离10 Gb/s系统可以直接升级至40 Gb/s系统,而不需要升级传输链路。但是,由于相对10 Gb/s系统而言40 Gb/s系统的色散容限非常小,在升级时必须精确补偿原有链路的色散,在接收机前一般需要加可调色散补偿单元。同时,还分析了光纤注入功率对系统性能的影响,结果表明在设计这种由10 Gb/s向40 Gb/s升级的系统时,不仅要考虑信号带宽增加带来信噪比要求的提高,而且必须充分考虑光纤非线性的影响。     

Wavelength conversion at 10 Gb/s using a semiconductor opticalamplifier

Data at 10 Gb/s has been translated from an input signal wavelength to another wavelength, either longer or shorter, using gain compression in a 1.5-μm semiconductor optical amplifier for wavelength conversion. To achieve operation at such high bit rates, the probe (shifted) input must be intense enough to compress the gain of the amplifier significantly. This reduces the gain recovery time of the amplifier because of probe stimulated emission. A consequence of the intense probe is an extinction ratio deduction. Using moderate input powers, wavelength conversion is achieved over a 17-nm (2-THz) range, with 0.7-3-dB power penalties     

100Gb/s光传输设备及测试

随着偏振复用正交相移键控（PM-QPSK）编码、基于数字信号处理（DSP）的相干接收、前向纠错（FEC）等关键技术的突破,目前100Gb/s光传输设备已发展成熟,相应测试仪表也有多个厂家推出,国内外针对100 Gb/s光传输设备的实验室和现网测试也已规模开展,虽然在性能测试方面存在部分尚未解决的难题,但整体上已为100 Gb/s光传输设备规模商用奠定基础。     

Wavelength shift keying modulation up to 35 Gb/s with wavelength tone reuse to multiplex two 40 Gb/s DPSK signals

Fast optical frequency shift keying or wavelength shift keying (WSK) modulation offers advantageous features for applications in long haul communications and in optical labeling for packet routing. This includes simple demodulation by optical filtering and constant amplitude envelope providing tolerance to fiber nonlinear effects during transmission. In this paper we report on the generation of WSK signals up to 35 Gb/s with reuse of the wavelength tones for polarization multiplexing two independent 40 Gb/s DPSK signals. Transmission over a 50 km fiber link of the resultant three channel signal is also reported.     

Demonstration of Broadband Wavelength Conversion at 40 Gb/s in Silicon Waveguides

We present ultra-broadband wavelength conversion in silicon photonic waveguides at a data rate of 40 Gb/s. The dispersion-engineered device demonstrates a conversion bandwidth spanning the entire $S$-, $C$-, and $L$-bands of the ITU grid. Using a continuous-wave $C$-band pump, an input signal of wavelength 1513.7 nm is up-converted across nearly 50 nm at a data rate of 40 Gb/s, and bit-error-rate measurements are performed on the converted signal.      

2.5Gb/s FSO-OFDM系统调制方式研究

OFDM是一种能有效抵御大气散射效应的调制技术,提出了一种实现FSO-OFDM传输的系统方案。对速率为2.5Gb/s的FSO-OFDM系统在不同的天气条件下进行了仿真研究。仿真分析了不同的调制方式和不同的子载波数时FSO-OFDM系统的误码率和光信噪比。仿真结果表明,与采用16PSK调制方式相比,采用16QAM方式系统将具有更低的误码率和更高的Q值。     

47.4 Gb/s Transmission Over 100 m Graded-Index Plastic Optical Fiber Based on Rate-Adaptive Discrete Multitone Modulation

We experimentally demonstrate a bit-rate of 47.4 Gb/s over 100 m of perfluorinated multimode graded-index plastic optical fiber (GI-POF) by exploiting discrete multitone (DMT) modulation with rate-adaptive bit-loading. The maximum achieved aggregate bit rate is 51.8 Gb/s including DMT transmission overhead (cyclic prefix and preambles) and the standard of 7% of forward-error-correction (FEC) overhead. This is achieved over an intensity-modulated direct-detection (IM-DD) link using a directly-modulated DFB laser (1300-nm) and a multimode fiber-coupled photodetector with a large diameter of 25-$mu$m. The bandwidth requirement is only 12 GHz due to the use of spectral-efficient modulation formats of up to 64-QAM.      

Jitter Challenges and Reduction Techniques at 10 Gb/s and Beyond

The bandwidths of high-speed input/output (I/O) links keep increasing to meet the ever-growing demands for high-speed communications. The data rates for the leading edge high-speed I/O standards have already increased to around 10 Gb/s, including 10 GB Ethernet (GBE, 10 Gb/s, or 4 $,times,$10.3125 Gb/s, and 10$,times,$10.3125 Gb/s for Ethernet 40 G/100 G), 8$,times$ fibre channel (8.5 Gb/s), and PCI Express Gen 3 (at 8 Gb/s). At those data rates, the total available timing budget become less, data-dependent jitter gets severe, and jitter amplification becomes significant. This paper focuses on these jitter challenges and associated mitigation/reduction technologies, including jitter tracking via clock recovery, eye-opening via equalizations, and DCD cancellation via delay elements to avoid jitter amplification.      

超100Gb/秒的光OFDM在光长度系统的传输

100 G Ethernet is considered to become the next generation Ethernet standard for IP networks. Typical 100 Gb/s transmission systems and their performance are presented. Comparision and analysis for 100 Gb/s transmission systems have been discussed. It is demonstrated that optical OFDM can be used in future 100 Gb/s/ch and long-haul system.     

超100G传输关键技术研究

N×100Gbit/sWDM系统已经趋于成熟并逐渐开始引入规模商用。网络带宽的持续快速增长促使骨干光传送网在未来向更高的传输速率演进。本文分析了超100Gbit/s的关键技术,并对未来超100Gbit/s技术发展的路线选择进行了探讨。     

4OGb/s光传输系统主要影响因素及解决方法

介绍了40Gb/s光传输系统的开发前景,对影响40Gb/s光传输系统的主要因素,如电子材料、光纤色散效应、偏振模色散(PMD)、非线型效应、光信噪比、全新的编码和调制方式等,进行了较为详细的论述,并介绍了解决这些影响因素的方法.     

10Gb／s光通信系统用高速超晶格雪崩二极管

介绍了载流子倍增层采用超晶格雪崩光电二极管（ＡＰＤ）的原理，分析了影响ＡＰＤ特性的离化机理。说明了利用超晶格异质界面大的导带不连续性是增大离化率比从而改善噪声、响应速度等特性的有效途径。最后介绍了超晶格ＡＰＤ的最新进展。     

10G以太网中多模光纤传输特性研究

首先介绍了10G以太网标准对局域网中已铺设多模光纤的传输距离要求和电色散补偿的技术方案。简单分析了不同折射率分布下的多模光纤的差分模延迟(DMD)曲线,随后讨论不同注入模式下多模光纤的模式分布与延迟特性。得到光脉冲注入位置在偏离纤芯19μm至22μm处有较好的色散性能。最后对多模光纤完整的脉冲响应和转移函数进行了讨论。     

Wavelength conversion at 10 Gb/s by four-wave mixing over a 30-nminterval

We show that the use of a long semiconductor optical amplifier increases the error-free conversion interval of a four-wave mixing (FWM)-based wavelength converter. 30-nm wavelength down-conversion and 15-nm up-conversion have been obtained at 10 Gb/s. This result is a significant improvement over the previous best performance of a FWM-based wavelength converter and suggests that the full erbium-doped fiber amplifier bandwidth can be covered with FWM wavelength converters     

2.5Gb/s和3.125Gb/s速率级0.35μmCMOS限幅放大器

采用了TSMC0.35μm CMOS工艺实现了可用于SONET/SDH2.5Gb/s和3.125Gb/s速率级光纤通信系统的限幅放大器。通过在芯片测试其最小输入动态范围可达8mVp—p，单端输出摆幅为400mVp-p，功耗250mW，含信号丢失检测功能，可以满足商用化光纤通信系统的使用标准。     

Greater than 200 Gb/s Transmission Using Direct-Detection Optical OFDM Superchannel

In this paper, we propose direct-detection optical orthogonal frequency division multiplexing superchannel (DDO-OFDM-S) and optical multiband receiving method (OMBR) to support a greater than 200 Gb/s data rate and longer distance for direct-detection systems. For the new OMBR, we discuss the optimum carrier-to-sideband power ratio (CSPR) in the cases of back-to-back and post transmission. We derive the analytical form for CSPR and theoretically verify it. A low overhead training method for estimating I/Q imbalance is also introduced in order to improve performance and maintain high system throughput. The experiment results show that these proposals enable an unprecedented data rate of 214 Gb/s (190 Gb/s without overhead) per wavelength over an unprecedented distance of 720 km SSMF in greater than 100 Gb/s DDO-OFDM systems.     

40Gb/s光纤链路的可视化建模及仿真研究

通过全数值计算方法,建立了40 Gb/s单信道传输链路的可视图形化模型.详细描述了光源、传输链路、光探测及判决单元的建模原理及求解方法,并对预啁啾归零码(CRZ)的传播过程进行了仿真研究,为教学演示及实验提供了良好、经济的仿真平台.