The analysis of system performance of WDM/OCDMA-PON based on DQPSK/OOK

This paper mainly studies the combination of quadrature modulation of the phase modulation/amplitude modulation. Phase domain modulation formats mainly study the differential quadrature differential phase shift keying (DQPSK) and amplitude domain modulation format mainly studies the on–off keying (OOK). Through the above analysis, we know orthogonal to modulation technology of OCDMA system solution-PON DQPSK/OOK based on has a large advantage over the ordinary PON system.     

Physical layer performance analysis of hybrid and stacked TDM–WDM 40G-PON for next generation PON

Current passive optical networks (PONs) (Gigabit PON (GPON) and Ethernet PON (EPON)) will run out of bandwidth sooner or later due to the ever increasing bandwidth demand. The aforementioned and the new next generation PON stage 1 (NG-PON1) standards (10 Gigabit-PON (XG-PON) and 10 Gigabit Ethernet-PON (10G-EPON)) are based on time division multiplexing (TDM-PON), which has its limitations such as limited bandwidth. In this paper, hybrid TDM–WDM PON and stacked TDM-PON architectures are evaluated and compared as solutions for NG-PON stage 2 (NG-PON2). Both architectures are fully capable of satisfying the requirements of NG-PON2. Stacked TDM-PON has the advantage of being compatible with the currently deployed optical distribution network (ODN). Considering four wavelengths and 10 Gb/s/wavelength, the hybrid TDM–WDM PON does not seem to offer noticeable advantages over stacked TDM-PON.     

一种多波长OCDMA解码器方案及其性能分析

提出了一种多波长OCDMA（MW OCDMA）系统的光解码器方案,通过多个光硬限幅器来抑制多用户干扰.分析了使用该解码器的MW OCDMA误码率性能、频谱效率和归一化吞吐量性能.分析结果表明,该方案能有效改善MW OCDMA系统的误码率性能,在要求的误码率条件下增加同时用户数,从而能有效改善MW OCDMA系统的频谱效率.同时,采用光硬限幅器的MW OCDMA 系统的归一化吞吐量性能明显提高,特别是归一化吞吐量峰值提高了约一倍.     

基于2D-OOC的OCDMA系统的地址码结构研究

提出了二维光正交码 (2D OOC)设计方案 ,围绕光码分多址 (OCDMA)技术实用化的两个主要指标—最大并发用户数和系统误码率的改进和提高 ,系统地研究了基于 2D OOC的OCDMA的性能 ,分析了 2D OOC码字的相关性 ,导出了系统的最大用户容量 ,详细研究了 2D OOC系统以多址干扰为主的系统误码率 .研究表明 :较之一维时域扩频码或一维谱域扩频码 ,2D OOC系统性能大大提高 ,在大信息量传输时 ,适当选择码长和码重 ,系统总容量可高达Tbits/s量级 ,性能优于基于 1D OOC的OWDM和OCDMA混合系统 .     

基于2D-OOC的OCDMA系统的地址码结构研究

提出了二维光正交码(2D-OOC)设计方案,围绕光码分多址(OCDMA)技术实用化的两个主要指标-最大并发用户数和系统误码率的改进和提高,系统地研究了基于2D-OOC的OCDMA的性能,分析了2D-OOC码字的相关性,导出了系统的最大用户容量,详细研究了2D-OOC系统以多址干扰为主的系统误码率.研究表明:较之一维时域扩频码或一维谱域扩频码,2D-OOC系统性能大大提高,在大信息量传输时,适当选择码长和码重,系统总容量可高达Tbits/s量级,性能优于基于1D-OOC的OWDM和OCDMA混合系统.     

Hybrid WDMA/OCDM system with the capability of encoding multiple wavelength channels by employing one encoder and one corresponding optical code

<正>A hybrid wavelength division multiple access(WDMA)/optical code division multiplexing(OCDM) system is proposed,where the optical code is not the same as the address of every optical network unit(ONU); rather,the code is a virtual fiber of hybrid passive optical network(PON).To our knowledge,this is the first report analyzing a single encoder/decoder with a single corresponding optical code being exploited to encode/decode multiple wavelength signals simultaneously.This system enables OCDM to become transparent to ONU so that the existing wavelength division multiplexing(WDM) PON can be upgraded. Thus,redesigning the optical line terminal and ONU can be easily accomplished,and greatly decreasing the number of encoder/decoder becomes possible.In experiment,we only employ two encoder/decoder pairs to combine two WDM-PONs in one fiber.Simulation results confirm the feasibility of the proposed system.     

OCDMA系统中2-D码和3-D码

光码分多址(OCDMA)技术主要应用在接入网中。设计大容量的地址码是该技术实用化的前提。本文在构造2 D素数码的基础上提出了一种用于OCDMA系统的空域/频域/时域3 D地址码。这种码基于素数序列运算。理论分析和数学计算结果表明，3 D码比2 D码的容量更大，系统带宽效率更高，误码率(BER)更低，表现出的性能更好。     

Tunable wavelength converters based switching structure for WDM-TDM hybrid PON

In the evolvement of Passive Optical Network (PON), the performance of hybrid Wavelength-Time Division Multiplexing based PON (WDM-TDM PON) is directly determined by the network architecture. This letter proposes a Tunable Wavelength Converter (TWC) based switching structure (TWC-SS) for WDM/TDM hybrid PON. Using the tunable wavelength converter technology, this Switch Node is designed and introduced into the hybrid WDM/TDM PON. Improved performances brought by the Switch Node on packet loss rate, bandwidth-utilization rate are proved by experimental results.     

基于超结构光纤光栅的正交四相光码分多址编/解码器

正交四相序列编码相比于二相序列具有更大的码字容量和更好的互相关特性,因此更适用于光码分多址(OCDMA)无源光接入网.提出并实现了一种基于超结构光纤光栅的正交四相光码分多址编/解码器.该编/解码器采用A族四相序列作为地址码,在制作的过程中仅需一个均匀相位掩模板即可实现编码功能,并且在性能上与传统工艺制作的编码器相当.为了与不同波长信道相匹配,提出了变信道编码技术,仿真结果表明采用该技术的编码器具有更高频谱效率,因此得到更好的编/解码性能.对一个码长63,长度4.1 cm的正交四相编/解码器进行了信息速率为2.5 Gb/s.码片速率为156 Gchip/s的编/解码实验,取得了较好的编/解码效果.     

Real-time monitoring implementation in a remote-pumped WDM PON

We report on an improved configuration to monitor a passive optical network with high quality in service. This proposed system comprises fiber-Bragg gratings, a 1 × 4 optical switch, and an optical time-domain reflectometry to diagnose the broken point in real time. It could simultaneously detect multioptical network units in a WDM PON. The remote-pump integrated residual pumping reused function is implemented. Broken points in different optical paths can be detected simultaneously even when the distances to the central office are identical. The bit-error rate testing is verified with a small power penalty, making it an ideal solution for the real-time monitoring in a WDM PON.     

一种光CDMA频域的二次方一致性码

在二次方一致性的基础上,构造了一种容量大、自相关和互相关特性好的码族研究表明,采用这个码族的光码分多址(OpticalCDMA)系统比波分复用(WDM)系统拥有大得多的用户数而且这个码族很适合于异步和多比特率接入的光码分多址系统据我们了解,这种码字用于在光码分多址非相干频域编制中为首次被提出.     

Bi-wavelength two dimensional chirped grating couplers for low cost WDM PON transceivers

We propose and demonstrate a bi-wavelength two dimensional (2D) waveguide grating coupler on silicon-on-insulator which has efficient coupling of optical light with two-wavelength bands independently between standard optical single mode fibers and nanophotonic waveguides. The details of design are described and the measurement results as well as system performance are experimentally characterized. The bi-wavelength grating coupler can be used as wavelength-division-multiplexing (WDM) splitter/combiner for monolithically silicon integrated transceivers, potentially meeting the low cost requirements for future WDM passive optical network (PON).     

The WDM–ROF–PON based on linearly-polarization dual-wavelength fiber laser and CSRZ–DPSK modulation

In this paper, we design a linearly-polarized dual-wavelength fiber laser used in WDM–ROF–PON, which can achieve wire-line and wireless access synchronously. With polarization multiplexing, the dual-wavelength fiber laser is the union light source of WDM–PON. With the CSRZ–DPSK modulation, the wireless access system of ONU can save RF source and the frequency of radio carrier can be controlled by OLT. The networking has the credible transmission property, including fiber transmission and wireless access.     

A scalable hybrid WDM/OCDMA-PON based on wavelength-locked RSOA technology

A novel architecture of hybrid WDM/OCDMA-PON employing two wavelength bands for two different groups of ONUs is proposed. OCDMA is overlayed on WDM channel in a single network and the total capacity of WDM/OCDMA-PON becomes 2m times larger than the traditional WDM-PON. Meanwhile, a C + L band ultra-broadband light source is used for upstream transmission, which can be seen as a cost-effective manner in FTTH. In simulation system, 1.25 Gb/s downstream and upstream data based on the architecture are transmitted with good performance. And the crosstalk penalties from adjacent code channels (at the same wavelength) are found to be little in upstream and downstream transmissions.     

Generation of DQPSK format and its performance against polarization mode dispersion

We propose a novel transmitter and receiver for differential quadrature phase-shift keying （DQPSK） format. The impact of the first-order polarization mode dispersion （PMD） on systems using DQPSK with 100- Gb/s non-return-to-zero （NRZ） or return-to-zero （RZ） format is investigated. Through computing the eye openings of DQPSK formats under different PMD conditions, it is found that NRZ DQPSK, as compared with RZ DQPSK, incurs smaller eye opening due to PMD. Carrier-suppressed return-to-zero （CSRZ） DQPSK format has better tolerance than RZ DQPSK format to PMD for a given bit rate.     

Millimeter-Wave over Fiber Systems Using Hybrid OCDM/WDM Transmission

In this paper, we propose and simulate 2 OCDM × 4 WDM transmission system for a millimeter-wave (60 GHz) over fiber system to be used in broadband wireless access networks (BWANs). The general system setup is devised and the necessary building blocks identified. Results gathered (for a 155 Mbit/s per user system) under worst case parameter specifications and settings suggest indicate that system performance is severely limited by optical multiuser interference (OMUI) penalties. Several methods to reduce the OMUI limitations are described. These methods should ensure that this transmission scheme possible wavelength-reuse option for future MMW BWANs.     

Bandwidth Allocation Method by Service for WDM EPON

A WDM(Wavelength Division Multiplexing) EPON(Ethernet Passive Optical Network) is an economical and efficient access network that has attracted significant research attention in recent years. A MAC(Media Access Control) Protocol of PON is based on TDMA(Time Division Multiple Access) basically, we can classify this protocol into a fixed length slot assignment method suitable for leased line supporting Qos(Quality of Service) and a variable length slot assignment method suitable for LAN/MAN with the best efforts. In this paper, we present bandwidth allocation method by service for WDM EPON and verify this method by simulation results.     

用于光码分多址系统的一种3—D地址码

在构造2—D码的基础上，提出并构造了一种用于OCDMA系统的新的空域／频域／时域     

ONU型网关融合接口的设计和实现

【】网关型ONU作为网关及PON技术的融合,不仅保持了PON原有的管理方式,还支持运营商实现远端管理。PON系统具有高带宽和低成本等优势。在ONU网关上开发融合无线接口,可以在支持传统有线业务的基础上,丰富光纤系统的接口种类。既保持原有优势,又增加系统的无线资源。传统的方法是在有线接入设备上开通无线接入通道,不能实现集中控制和管理。针对现有技术的不足,提出了新的设计方法,采用基于FPGA和嵌入式处理器的方法。进一步给出了详细的实现过程。测试验证表明该设计比原有方案有优势。     

Analysis of electrically configurable spectral phase encoding techniques for optical CDMA

We present the theoretical analysis and simulation of an encoder/decoder pair with applications in Optical Code Division Multiple Access (OCDMA) systems. The theory and simulations presented are valid for any technique that relies on the combination of dispersion/phase modulation/dispersion for spectral phase encoding. We perform a theoretical study of the system, characterizing its main limiting factors, and a comparative study of the Multi-Access Interference (MAI) and Bit Error Rate (BER) for a simple multi-user system at high-bit rate in a Passive Optical Network (PON) environment. The capacity of the system to carry out error-free operation for codes of different length and with different numbers of users is also demonstrated through simulation.