Session 3P4a 4 FocusSession.SC4&3: Radio over Fiber Systems and Components

Transcription

1 Session 3P4a 4 FocusSession.SC4&3: Radio over Fiber Systems and Components Intelligent Radio-over-fiber System Based on MWP for the Broadband Access and Ubiquitous Sensing Kun Xu, Fiber-wireless Links Supporting High-capacity W-band Channels J. J. Vegas Olmos, Idelfonso Tafur Monroy, Wired and Wireless Seamless MIMO Transmissions in Millimeter-wave Radio-over-Fiber Systems Yuki Yoshida, Carrier Phase and Amplitude Manipulation for Linearization and Dispersion Compensation in Radioover-fiber Systems Using Mach-Zehnder Modulator Shangyuan Li, Xiaoping Zheng, Fan Wei, Hanyi Zhang, Bingkun Zhou, Digitized RF Transport for Fiber-wireless in a World of Digital Optical Networks Christina Lim, Yizhuo Yang, Ampalavanapillai Nirmalathas, Linearization Techniques for Broadband Radio over Fiber Transmission John Xiupu Zhang, Bouchaib Hraimel, Ran Zhu, Dongya Shen, Taijun Liu, A Study on OFDM Millimeter-wave Radio over Fiber System Tam Hoang Thi, Mitsuji Matsumoto,

2 1144 Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Sweden, Aug , 2013 Intelligent Radio-over-fiber System Based on MWP for the Broadband Access and Ubiquitous Sensing Kun Xu State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications, China Abstract Broadband, ubiquitous and convergent transmission and access of information has become the most important engine to push forward the development of the modern information society. Thus, broadband access and ubiquitous sensing of information has been rapidly developed as the important and necessary performance demand of the future high-performance information system. However, the current microwave and digital technologies have become less and less competent for the requirement of the future information network and high-performance digital receiving system. As a result, some brand-new solutions are strongly desired to be explored to keep the pace of the fast development of the modern information society. Microwave photonics with combination of microwave and lightwave is found to be an effective solution to broadband access and ubiquitous sensing, of which the fundamental theory is to use photonic technologies to generate, transmit, process, and control microwave signals. Microwave photonic takes full advantages of the respective merits of microwave technology and lightwave technology to compensate the drawbacks of each other and eventually bridges the gap between microwave and lightwave effectively. Specifically speaking, microwave photonics makes use of the wideband, high-speed and low SWaP of photonics technology to achieve the high-quality generation of broadband microwave signal, high dynamic range transmission of analog microwave information, high-resolution processing of high-frequency microwave signal, flexible signal controlling, reconfigurable dynamic networking and the coordination between microwave and lightwave in the distributed networks. Taking advantage of the microwave photonics technology, we proposed intelligent radio-over-fiber (I-RoF) distributed antenna system (DAS) for the green, broadband access and ubiquitous sensing applications. The I-RoF DAS provide a promising solution for the future multi-service broadband green access and ubiquitous sensing applications. In the physical layer, the analog-optic links with high spur-free dynamic range (SFDR) are mathematical modeled and experimentally established. Furthermore, the different topologies (star, tree, etc.) of ROF network are proposed for the complex application environment. In the media access control (MAC) layer, an optimized MAC model for dynamic reconfigurable ROF network is proposed to overcome the impact of additional delay induced by the optical fibers. Moreover, by applying the intelligent DAS, the efficient utilization and dynamic management of the optical and microwave resources is realized. Consequently, an intelligent radio-over-fiber (I-RoF) distributed antenna system is implemented with the function modules of intelligent sensing and photonic RF switching, which provides a promising solution to the converged broadband access and sensor networks. As the development of microwave photonics, it will be widely deployed in the national strategy industries such as broadband wireless communications, defense, aerospace and medical industry. Based on a national 973 project that Beijing University of Posts and Telecommunications leads, the intelligent radio-over-fiber based on microwave photonics researches and applications in broadband access and ubiquitous sensing will be given in this talk.

3 Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Sweden, Aug , Fiber-wireless Links Supporting High-capacity W-band Channels J. J. Vegas Olmos and I. Tafur Monroy Department of Photonics Engineering, Technical University of Denmark, Kgs. Lyngby 2800, Denmark Abstract Seamless convergence of fiber-optic and the wireless networks is of great interest for enabling transparent delivery of broadband services to users in different locations, including both metropolitan and rural areas. Current demand of bandwidth by end-users, especially using mobile devices, is seeding the need to use bands located at the millimeter-wave region ( GHz), mainly because of its inherent broadband nature. In our lab, we have conducted extensive research on high-speed photonic-wireless links in the V-band (50 75 GHz) and the W- band ( GHz). In this paper, we will present our latest findings and experimental results on the W-band, specifically on its GHz sub-band. These include photonic generation of millimeter-wave carriers and transmission performance of broadband signals on different types of fibers and span lengths.

4 1146 Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Sweden, Aug , 2013 Wired and Wireless Seamless MIMO Transmissions in Millimeter-wave Radio-over-Fiber Systems Yuki Yoshida Graduate School of Engineering, Osaka University 2-1 Yamada-oka, Suita, Osaka , Japan Abstract Seamless connection between wired (optic fiber) and wireless (radio) networks is an attractive technology not only for the last-mile problem in access networks including mobile backhauls, but also for the enhancement of network resilience against a disaster. In particular, on March 11, 2011, the Great East Japan Earthquake cut off a large number of optical fiber cables, and the most of broadband services were disconnected. The temporal deployment of broadband connections using wired and wireless converged systems immediately after a disaster has been strongly desired for rescue and surveillance, since the re-establishment of the optical back-haul network takes 1 2 years long. Millimeter-wave (MMW) radio with radio-over-fiber (RoF) technology is a prominent solution for providing wired/wireless seamless connection with a capacity greater than 10 Gbps, which is capable for a fast protection link for recovery. The capacity also meets the demand for backhauling the high-speed wireless systems such as IMTadvanced or for relaying the upcoming optical access systems such as 10 G-PON. In this talk, the recent development of the Agile deployment capability of highly resilient optical and radio seamless communication systems program (the commissioned research of the National Institute of Information and Communications Technology, Japan) is introduced. Key technologies are 1) efficient W-band radio ( GHz), whose available bandwidth is > 30 GHz with low atmospheric attenuation of < 1 db/km, signal generations using photonic direct up-conversion, 2) DSP (digital signal processing)-aided optical coherent receiving techniques which offers the > 30 GHz ultra-wideband signal reception, as well as 3) wireless/wired seamless multiple-inputmultiple-output (MIMO) transmissions providing further capacity and robustness to the RoF link. We also present some experimental demonstrations including the 74.4 Gbps wired and wireless seamless MIMO transmission utilize W-band radio ( GHz) and fiber s polarization channels.

5 Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Sweden, Aug , Carrier Phase and Amplitude Manipulation for Linearization and Dispersion Compensation in Radio-over-fiber Systems Using Mach-Zehnder Modulator Shangyuan Li, Xiaoping Zheng, Fan Wei, Hanyi Zhang, and Bingkun Zhou Tsinghua National Laboratory for Information Science and Technology Department of Electronic Engineering, Tsinghua University, Beijing , China Abstract In radio-over-fiber (ROF) systems, electrical signal modulates the optical carrier, converting the electrical signal to optical domain and generating the up-converted signal bands. Comparing to the ideal modulation process, an actual modulation process would deteriorate the modulated signal and generate distorted sidebands, leading to a reduction of the dynamic range. Meanwhile, the chromatic dispersion, originated from the transmission fiber or other devices, can also change the phase relationship between the carrier and the modulated sidebands, introducing power fading to the modulated signal and causing significant signal degradation. Most traditional compensation methods have only focused on one of these two issues. However, for such an ROF system, they should better be treated simultaneously. Mach-Zehnder modulators (MZM) is generally treated as an electrical to optical (EO) converter. However, recent progresses show that the MZM (or an MZM with complex structures) can play far more than an EO converter. Special utilizations of the MZM can achieve linearization or dispersion compensation, and even resolve both the issues simultaneously. In this paper, we reviewed the fundamental principles, techniques, systems and applications that using MZMs to control the phase and amplitude of the optical carrier, to achieve multi-functions, including EO conversion, linearization and dispersion Compensation, simultaneously. By controlling the phase and amplitude of the optical carrier, the phase and amplitude relationship between the carrier and the sidebands can be altered accordingly. Analysis shows that the nonlinear distortion and fiber dispersion can be suppressed and compensated simultaneously, if a specific phase and amplitude condition between the carrier and the sidebands is settled. Such a condition can be achieved using a dual-parallel MZM (DPMZM), which has two sub-modulators that lie on a parent modulator. By tuning the three biases of the DPMZM, dispersion and nonlinear distortion can be treated at the same time. Further studies show that such a technique can help establishing a frequency doubled opto-electronic oscillator (OEO), or a low-interference dual-direction RoF links.

6 1148 Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Sweden, Aug , 2013 Digitized RF Transport for Fiber-wireless in a World of Digital Optical Networks Christina Lim, Yizhuo Yang, and Ampalavanapillai Nirmalathas Department of Electrical and Electronic Engineering, The University of Melbourne, VIC 3010, Australia Abstract Fiber-wireless technology is able to unify the future telecommunication infrastructure by using a common backhaul network to support both wired and wireless services. Despite the elegance of the fiber-wireless architecture, previous study has shown that the performance is severely limited by the nonlinearity in the optoelectronic frontend [1]. Previously we have introduced and demonstrated the use of digitized wireless signal transport to overcome the inherent nonlinearity issue [2]. In this paper, we review how this transport strategy is able to improve the performance of fiber-wireless links while being compatible with a predominantly digital world. Digitized RF-over-Fiber (DRoF) Transport of OFDM Wireless Signals: Figure 1 shows the digitized radio-over-fiber (DRoF) concept using bandpass sampling technique that undersamples the wireless signals with sampling rate proportional to the wireless message bandwidth that relaxes the ADC/DAC requirements within the remote base stations [3]. Since the wireless signal is transported digitally, the optical link can maintain its dynamic range independent of the fiber transmission distance until when the received signal goes below the link sensitivity. Fig. 2 shows the experimental setup for the DRoF transport of wideband OFDM signal (128 carriers, 80 modulated with 4-QAM, data rate of 1.25 Gb/s) generated using arbitrary waveform generator (AWG) [4]. The upconverted OFDM signal was bandpass sampled, digitally processed and externally modulated onto a DFB laser. The optical signal was transported over 20 km of fiber, detected and digitally processed off-line. Shown in Fig. 3 is the error vector magnitude (EVM) performance of the OFDM signals at 6 10 GH RF frequency as a function of ADC bit resolutions and the corresponding optical bit rates. The dashed line indicates error-free reception for 4-QAM signal. The performance improves with increasing ADC resolution before leveling off at an ADC bit-resolution of 6 bits. Also shown in Fig. 3 are the 4-QAM constellations of the original and the recovered signal after transmission with 4, 6 and 8 bit resolution. It can be seen that error-free transmission is achieved for wideband OFDM transmission using DRoF with ADC bit resolution as low as 4 bits with a total optical bit rate of 4 Gb/s. Digital Signal Processor Digitized RF E/O Downlink O/E DAC BPF Digital Signal Processor Digitized RF O/E CO Uplink E/O BS ADC Digitized RF-over-fiber Figure 1: Digitized RF-over-fiber transport. Figure 2: Experimental setup. Figure 3: EVM performance and constellation diagram.

7 Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Sweden, Aug , Conclusions: We have experimentally demonstrated the DRoF scheme for the transport of wideband OFDM wireless signals to increase the fiber-wireless capacity. REFERENCES 1. Kurniawan, T., et al., IEEE MTT, Vol. 54, , Gamage, P. A., et al., Proc. MWP2008/APMP2008, 15 18, Akos, D. M., et al., IEEE Trans. Comm., Vol. 47, , Yang, Y., et al., Proc. OFC, OTu2H.6, 2012.

8 1150 Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Sweden, Aug , 2013 Linearization Techniques for Broadband Radio over Fiber Transmission Xiupu Zhang 1, 2, Bouchaib Hraimel 2, Ran Zhu 2, Dongya Shen 1, and Taijun Liu 3 1 School of Information Science & Engineering, Yunnan University, Kunming, China 2 Department of Electrical & Computer Engineering, Concordia University, Montreal, Canada 3 College of Information Science & Engineering, Ningbo University, Ningbo, Zhejiang, China Abstract Linearization techniques are reviewed for broadband radio over fiber transmission. Three linearization techniques based on optical mixed polarization, analog predistortion and digital predistortion are summarized. Summary The current wireless signal distribution based on optical digital transmission or microwave point to point transmission is not appropriate for next generation broadband wireless access networks (BWAN) that can support data rate of up to Gb/s. Analog radio over fiber (ARoF) is considered a key enabling technology for BWAN because of its optical broadband and cost effective seamless integration to wireless technologies and transparent to radio frequency carriers and data protocols. Because of its analog modulation nature, ARoF transmission is very susceptible to intrinsic nonlinearities from the electro-optical modulation (EOM) and any other optical and electronic components that are used for transmission. Therefore, the deployment of ARoF in BWAN requires cost effective broadband linearization. Linearization is not a new research topic and two types of linearization had been proposed: analog and digital predistortion. Unfortunately, the proposed techniques were narrow band, typically limited to 20 MHz. Due to the above, broadband linearization techniques have been intensively developed. In this presentation, we will review linearization techniques using optical mixed polarization (OMP), analog predistortion circuit (APDC) and digital predistortion. The OMP, making use of the two polarization states of light and the polarization dependence of the optical modulator to compensate for its nonlinearity, is used to linearize optical modulators, such as Mach-Zehnder modulator (MZM) and electro-absorption modulator (EAM). Using OMP for MZM and EAM, spurious free dynamic range (SFDR) is improved by more than 10 db. By combining OMP and semiconductor optical amplifier (OSA) for an MZM, a record SFDR of 130 db/hz 4/5 and more than 10 db of improvement in error vector magnitude (EVM) have been achieved for multiband- OFDM ultra-wideband signal. Broadband APDCs (in 2 6 GHz and 7 18 GHz bands) have been designed using broadband reflective Schottky diodes. An improvement of more than 10 db in SFDR has been achieved over 10 GHz. Using digital predistortion (DPD) to linearize sparse multi-band RF signals in subcarrier multiplexed (SCM) ARoF, a 15 db suppression of adjacent power ratio (ACPR) is achieved in two 64 QAM modulated OFDM signals on 2.4 and 3.6 GHz bands.

9 Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Sweden, Aug , A Study on OFDM Millimeter-wave Radio over Fiber System Tam Hoang Thi and Mitsuji Matsumoto Graduate School of Global Information and Telecommunication Studies, Waseda University, Tokyo, Japan Abstract In this paper, we investigate and theoretically analyze the performance of OFDM based signal transmission over Millimeter-Wave Radio-over-Fiber systems in term of SDR (signal to distortion ratio) and BER (bit error rate). A novel configuration which has ability to transmit very high bit-rate data at a rather low cost is proposed. Moreover, the factors that affect the performance of this system are shown. Introduction: At the present, the development of new services that require higher bit-rate such as video conference, HD video etc drives the network provider to upgrade the network to higher speed. On the other hand, the services price should be reduced due to competitive pressure. Therefore, we need a new technology that can provide huge bandwidth at a rather lower cost. Radio over fiber technology at millimeter wave can be a good candidate. The reason is that the license-free spectrum at 60 GHz is free and such high frequency can provide very broad bandwidth. However, signal transmission at extremely high frequencies faces many challenges such as high attenuation. In addition, the size of radio cell is very small so the number of base station will rise sharply. Radio over fiber technology is used because in this technology, the structure of base station is simple and as the result, the cost is low. Besides, the importance of OFDM based signal has increased in relation to the definition of standards, like LTE and WiMAX. It is necessary to analysis performance of the new system that transmit OFDM based signal over millimeter wave over Radio over Fiber. The combination of those advanced technologies is supposed to bring good results and this can be good candidate for next generation network. The system model is shown at the figure below. Mach Zehnder Modulator is used as the external modulator.

10 1152 Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Sweden, Aug , 2013