Low-Cost Transparent Radio-Over-Fiber System for In-Building Distribution of UWB Signals

This paper investigates hybrid fiber-radio networks for in-building distribution of ultrawideband (UWB) signals, in order to extend UWB radio coverage area. An original multipoint to multipoint UWB-over-fiber system, proposed in the frame of BILBAO project, is presented and discussed. System link gain and noise figure are evaluated through theoretical analysis. A simulation model is used to study the impact of E/O transceivers nonlinearity on UWB signals. Experimental results show good agreement with simulation results. A high data rate file transfer, with UWB radio propagation and transmission over 100 m of multimode fiber, has been also successfully demonstrated.      

Experimental Demonstration of All-Optical 781.25-Mb/s Binary Phase-Coded UWB Signal Generation and Transmission

In this letter, an all-optical incoherent scheme for generation of binary phase-coded ultra-wideband (UWB) impulse radio signals is proposed. The generated UWB pulses utilize relaxation oscillations of an optically injected distributed feedback laser that are binary phase encoded (0 and $pi$) and meet the requirements of Federal Communications Commission regulations. We experimentally demonstrated a 781.25-Mb/s UWB-over-fiber transmission system. A digital-signal-processing-based receiver is employed to calculate the bit-error rate. Our proposed system has potential application in future high-speed UWB impulse radio over optical fiber access networks.      

Combined Analysis of OFDM-UWB Transmission in Hybrid Wireless-Optical Access Networks

The hybrid wireless-optical transmission of ultra-wideband signals employing orthogonal frequency-division multiplexing modulation (OFDM) ultra-wideband (UWB) as defined in the ECMA-368 standard is experimentally analyzed in this letter. The OFDM-UWB signals provide 400 Mb/s per user at optical distances from 5 to 50 km on standard single-mode fiber (SSMF). The analysis includes the wireless radiation from 0 to 3 m after optical transmission. The results indicate a maximum error-vector-magnitude degradation of 2.5 dB measured at 1.5-m radio after 50-km SSMF optical transmission for the first two UWB channels. This degradation translates to 1-m maximum wireless-reach penalty.     

Joint Distribution of Polarization-Multiplexed UWB and WiMAX Radio in PON

In this paper, the feasibility of the joint distribution of ultra-wideband (UWB) and WIMAX wireless using polarization multiplexing as a coexistence technique is proposed and experimentally demonstrated within the framework of passive optical networks (PON). Four single- and orthogonal-polarization multiplexing schemes are studied targeting to reduce the mutual interference when UWB and WiMAX are distributed jointly through standard single-mode fiber (SSMF) without transmission impairments compensation techniques and amplification. Experimental results indicate successful transmission up to 25 km, in SSMF exceeding the range in typical PON deployments. The radio link penalty introduced by optical transmission is also investigated in this paper.      

Experimental Comparison of Transmission Performance of Multichannel OFDM-UWB Signals on FTTH Networks

The experimental demonstration of radio-over-fiber Wimedia-defined OFDM ultrawide band (OFDM-UWB) wireless transmission in fiber-to-the-home (FTTH) networks using standard single-mode fiber with lengths ranging from 25 to 100 km is reported in this paper.      

基于光纤光栅的超宽带信号产生与传输

针对现有方法功率利用率低与调制实现困难的问题,采用基于光纤光栅（FBG）的超宽带（UWB）调制信号产生方法,建立了UWB信号产生系统。不仅可以实现UWB信号的调制,而且提高了产生信号的信噪比。实现了二进制相位调制（BPM）、脉冲幅度调制（PAM）和脉冲位置调制（PPM）等UWB信号产生。分析了光纤传输对产生信号的影响,...     

Key technologies and system design for various radio over fiber applications

Key technologies and new system designs for various radio over fiber (RoF) applications are proposed and demonstrated. For ultrawideband (UWB) over fiber applications, several UWB pulses generation and distribution methods are carried out. Different kinds of UWB pulses are generated based on cross-polarization modulation methods. For millimeter-wave (mm-wave) wireless applications, a 32 GHz RoF system is demonstrated with microwave frequency sextupling by optical methods. After 20 km SMF transmission, the power penalty of 2.5 Gbit/s downlink service is less than 0.15 dB. It is also suitable to apply dense wavelength division multiplexing (DWDM) technology to RoF system to support numerous base stations (BSs).     

An IR-UWB Photonic Distribution System

Experimental results are presented for a novel distribution system for an impulse radio ultra-wideband (UWB) radio signals employing a gain-switched laser. The pulse position modulated short optical pulses with a bit rate of 1.25 Gb/s are transmitted over fiber to a remote antenna unit, where the signal is converted to the electrical domain and undergoes spectral shaping to remove unwanted components according to UWB requirements. An experimental radio terminal has also been constructed to enable bit-error-rate measurements to be carried out. These experiments show that the optical distribution system will be capable of supporting the radio part of the system.      

Photonic Generation of Ultrawideband Signals

Ultrawideband (UWB) that is regulated by the Federal Communications Commission (FCC) for short-range high-throughput wireless communication and sensor networks with advantageous features, such as immunity to multipath fading, extremely short time duration, being carrier free, and having low duty cycle, wide bandwidth, and low power spectral density, has been a topic of interest recently. By wireless transmission, UWB communications systems can only operate in a short distance of a few meters to tens of meters. The convergence of UWB and optical fiber distribution techniques, or UWB over fiber, offers the availability of undisrupted service across different networks and eventually achieves high-data-rate access at any time and from any place. To distribute the UWB signals over the optical fiber, it is also desirable that the UWB signals can be generated in the optical domain without having extra electrical-to-optical conversion. In addition, UWB signals that are generated in the optical domain can be easily tailored to have a spectrum that meets the FCC-specified spectral mask. In this paper, techniques to generate UWB signals in the optical domain will be discussed. These techniques are divided into three categories, with the generation of UWB signals based on the following: 1) phase-modulation-to-intensity-modulation conversion; 2) a photonic microwave delay-line filter; and 3) optical spectral shaping and dispersion-induced frequency-to-time mapping. The areas for future development and the challenge of implementation of these techniques for practical applications will also be discussed.     

480-Mbps, Bi-Directional, Ultra-Wideband Radio-Over-Fiber Transmission Using a 1308/1564-nm Reflective Electro-Absorption Transducer and Commercially Available VCSELs

We describe 480 Mbps, bi-directional ultra-wideband (UWB) radio signal transmission over 1 km of single-mode optical fiber. Key components are a highly linear, reflective electro absorption transducer (EAT) and commercially available 1308-nm and 1564-nm VCSELs with 4.8-GHz bandwidth. Detailed EAT and 1308-nm VCSEL distortion analyses and measurements are presented highlighting the low intermodulation and harmonic distortion necessary for typical $-$18-dB wireless channel error vector magnitudes (EVMs). Direct VCSEL modulation with Wimedia supported band group 1 (3.1–4.8 GHz) MB-OFDM UWB signals was modelled with VPItransmissionMaker, suggesting a minimum EVM of $-$18.733 dB at 0.4502 OMI. This was confirmed by 480 Mbps upstream and downstream EVM measurements over fiber of $-$21.4 dB or better. Fully functional, half-duplex, bi-directional data transfer was achieved with interlocked RF switches.      

基于10G EPON的广电FTTH跨越式升级策略

随着数字化、高清化技术的发展,传统的HFC网络面临着巨大的挑战。利用10G EPON技术对广电HFC网络实施FTTH升级改造,可有效兼顾现有网络的光纤资源,以低成本投入实现从光进铜退到千兆入户的跨越式升级。文中分析了基于10G EPON技术的广电HFC向FTTH跨领域迁移的技术方案及应用现状,并结合实际工程建设情况,经过系统性的测试,验证了所提方案的可靠性和实用性。     

FTTH技术在广播电视网络中的应用

随着科技的不断发展,FTTH（Fiber To The Home)技术即光纤到户技术正逐渐在全球范围得到推广与应用。该技术以光纤为传输媒介,应用优势非常显著,能有效提升现代广播电视网络传输质量,使其覆盖范围进一步扩大。文中在了解FTTH技术新特征的基础上,阐述了FTTH技术在广播电视网络中的应用与效果,展望了FTTH 技术的发展方向。     

A simple broad-band coherence multiplexed optical access networkand its scalability

This paper proposes a novel and simply configured broad-band optical access network that uses coherence multiplexing (CM) and half-duplex bidirectional transmission. It allows the on-demand use of broad bandwidth on existing fiber-to-the-home (FTTH) access lines. The design of the proposed CM network considers degradation factors in CM systems. This paper introduces two analyses. The first one is a numerical simulation to optimize the tradeoff between available user number and fiber dispersion degradation, and the second estimates acceptable access-line loss in the network. These analyses show that 16 users×100 Mb/s (or 12 users×155 Mb/s) bandwidth Is possible on a standard single-mode fiber access line whose loss and length are under 9 dB and 10 km (and 7 km), respectively. The feasibility and scalability of the proposed network are verified by an experiment in which eight-channel 155-Mb/s half-duplex optical packet transmission is successfully demonstrated on a 7-km standard fiber access line with bit error rates better than 1×10^-9. This study shows that the capacity of existing FTTH access lines that employ star couplers can be significantly enhanced     

老旧小区广电网络改造中的共建共享模式实践

本文结合"十四五"广电网络FTTH总体建设目标,以及"网络提质工程"要求,以老旧小区改造为契机,制定了广电行业老旧小区网络改造工程施工规范,以集约化思维布局智慧广电网络,创新网络运营商"四合一"共建共享新模式,进一步推动了广电网络光纤化覆盖规模和进度.     

Performance Analysis of UWB Channels for Wireless Personal Area Networks

Ultra-wide band (UWB) communication is one of the most promising technology for high data rate networks over short-range communication. The ultra-wide bandwidth offers pulses with very short duration that provides frequency diversity and multipath resolution. Ultra-wide band (UWB) channels raise new effects in the receiver, the amplitude fading statistics being different compared to the conventional narrow band wireless channels. This review paper focuses on modeling of ultra-wide band channels, especially for simulation of personal area networks and also discusses the benefits, application potential and technical challenges in wideband communication. The concept of Orthogonal Frequency Division Multiplexing (OFDM) has recently been applied in wireless communication systems due to its high data rate transmission capability with high bandwidth efficiency and its robustness to multi-path delay. UWB OFDM communication was proposed for physical layer in the IEEE 802.15.3a standard which covers wideband communication in wireless personal area networks. Since the channel model for multicarrier UWB communication is different from that of plain ultra-wide band channel, a novel modification method in UWB channel model is proposed with specific center frequency and multipath resolution. Moreover, dynamic channel estimation is necessary before demodulation of UWB OFDM signals since the radio channel is time varying and frequency selective for wideband systems. The performance of the proposed method is statistically analyzed using LS and MMSE based channel estimation methods.     

Review of Glass and Polymer Multimode Fibers Used in a Wimedia Ultrawideband MB-OFDM Radio Over Fiber System

In this paper, we have exhibited the potential of the glass- and polymer-based multimode fibers to be used in a radio over fiber (RoF) system in order to extend the indoor coverage of the Wimedia multiband orthogonal frequency division multiplexing (MB-OFDM) ultrawideband (UWB) standard. After the design of a test setup operating at 850 nm, we have performed the physical characterization of the RoF system especially the mask test compliance, the error vector magnitude (EVM), or the relative constellation error (RCE) variation as a function of the system parameters [radio frequency (RF) power, optical attenuation, fiber length, laser bias current]. The transmission performance of both 200 and 480-Mb/s Wimedia signals is demonstrated through a 100-m link length of glass- and polymer-based multimode fibers: transmission penalties are quantified by RCE with values under the standard requirements. Two different behaviors depending on the core material of the fiber have been identified in this study.      

Coexistence Between UWB and Narrow-Band Wireless Communication Systems

Ultra-wide-band (UWB) signals are suitable for underlay communications, over a frequency band where, possibly, other systems are active. Such coexistence of UWB and other systems is possible if the mutual interference has a small impact on their respective performance. This paper aims to present recent results on the interference and coexistence among UWB systems and other conventional narrow-band (NB) systems. Specifically, we consider a point-to-point UWB (NB) link under the interference generated by a finite number of NB (UWB) radio transmitters. We consider channels including additive white Gaussian noise and multipath fading both for the victim and the interfering links, and different receiver architectures. While our main focus is on UWB systems based on impulse radio, wide-band systems employing carrier-based direct-sequence spread-spectrum and orthogonal frequency-division multiplexing are also considered.      

认知超宽带网络的容量分析和最优化

The integration of cognitive radio and Ultra wideband (UWB) networks has attracted lots of research interests. Cognitive UWB networks not only provide very high data rates but also guarantee the uninterrupted communication of primary system operated in the same frequency band. In this work, the problem of the capacity analyses of cognitive UWB networks is investigated. Different from the conventional cognitive spectrum sharing model which can only utilize the idle spectrum hole, the cognitive UWB system can...     

广电运营商应根据自身特点确定双向网改模式

随着三网融合步伐加快,广电与电信运营商业务趋于同质化,竞争趋于白热化。为支撑多业务发展,广电数字化双向网改和电信FTTH工程正在加速推进,逐渐向光网时代迈进,FTTH是网络发展的终极方案,但从传输架构、业务承载能力等方面分析,广电网络改造必须选择符合自身发展的模式。