Radio-over-Fiber Multi-service MM-Wave Interconnection with Photonic Up-conversion, Dual Band Remote Delivery and Photonic Envelop Detection
ABSTRACT A broadband radio-over-riber architecture with dual-band remote delivery capabilities based on photonic up-conversion and envelop detection for wireless and wireline multi-service transmission is proposed. The architecture has been experimentally demonstrated for Gigabit-Ethernet wireless LAN interconnection employing millimeter-wave point-to-point radio links. Moreover, the simultaneous transmission of digital base-band data and intermediate-frequency signals has been analytically investigated.
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ABSTRACT: Broadband access networks are evolving towards Gb/s user connectivity. This evolution requires both the development of core/metro networks with 100 Gb/s and beyond capacity per wavelength and the implementation of access networks able to provide such data rates. Key issues such as core/metro and access edge compatibility or seamless and ubiquitous provision of such broadband data and services, for instance using wireless access, will also require pushing the current technology limits further. As in the core/metro segment, 1-10 Gb/s capacity in the access network makes mandatory the use of optical fiber. Therefore, microwave–photonic technologies are candidate to ensure that such requirements are provided with the required performance and flexibility, offering the capacity and transparency required to provide seamless connections with data speeds in excess of 1 Gb/s in the access network. In this paper, an overview of microwave photonic state of the art to implement beyond 10G wireless access is provided, focusing on photonic vector modulation techniques, and the potential and required evolution of microwave-photonic technologies and radio-over-fibre systems to provide such infrastructures outlined Introduction – Broadband access networks are evolving towards 10G connectivity provision. In some scenarios, the possibility of providing such data rates via wireless links is highly interesting due to the inherent benefits of broadband wireless access (BWA) networks: faster and cheaper deployment, quicker revenue, user ubiquity, or reconfiguration/flexibility, among others . Moreover, wireless links are highly complementary to wireline networks as offer redundancy/back-up solution to improve network performance under disaster or service disruption situations . With the widespread adoption of Fiber-to-the-Home (FTTH) access networks, wireless transmission of multi-Gb/s signals has raised a lot of research interest in order to provide a solution to implement the wireless extension of FTTH networks, also known as Fiber-to-the-Air (FTTA). Radio-over-Fibre technologies [3, 4] offer the required bandwidth and flexibility to be able to implement these challenging communication systems, overcoming the main limitations of purely electrical approaches [5-11]. However, conventional methods based on direct upconversion of the digital baseband signal [6-13] suffer from huge bandwidth constraints, in particular when thinking on realistic full-duplex deployments where the used bandwidth is required in both downstream and upstream links. Therefore, approaches to reduce the radiated signal bandwidth such as using single-sideband schemes  or the use of more spectrally efficient modulation formats such as multi-level quadrature amplitude or phase modulation (MQAM or MPSK, respectively) is of high interest to alleviate such problems [13, 17]. Recently, we have proposed several PVM architectures with low hardware requirements, both optical and electrical showing the potential of this approach to generate up to 3.6 Gbit/s and 10 Gb/s QPSK and 16-QAM 40 GHz carriers [18-23]. For instance, figure 1 shows an schematic of a PVM modulator  that has been used to generate a 10 Gb/s 16 QAM 40 GHz carrier. Figure 1: 16 QAM PVM architecture (left) and Downconverted 10Gb/s In-phase (a), and Quadrature (b) components, and resulting normalised constellation diagram (c) (right).
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ABSTRACT: A full-duplex radio-over fiber system for the transmission of Gigabit Ethernet signals in the mm-wave band has been demonstrated under a field trial, providing redundant connections and point-to-point wireless extension of optical GbE networks.Optical Fiber Communication and the National Fiber Optic Engineers Conference, 2007. OFC/NFOEC 2007. Conference on; 04/2007
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ABSTRACT: In this paper, two photonic vector modulator (PVM) architectures are presented, and their use in generating multi-gigabit-per-second M-ary quadrature amplitude modulation/M-ary phase shift keying modulated RF carriers in the millimeter-wave frequency regime is experimentally demonstrated. First, a highly scalable photonic quadrature amplitude modulation (QAM) architecture based on vector summation and dispersive delay lines, which directly generate multilevel signals from parallel in-phase and quadrature components, is proposed and experimentally demonstrated by generating up to 3-Gb/s quadrature phase shift keying (QPSK), four-level amplitude shift keying, and eight-level QAM at 39-GHz-modulated carriers. The possibility of also detecting the baseband components is shown, which allows the simultaneous feeding of baseband/RF signals over the same infrastructure. This architecture is limited to a certain length of fiber, as the quadrature condition is obtained for a certain aggregated dispersion. To overcome this limitation, a second PVM architecture is proposed, which is based on the use of two Mach-Zehnder modulators in parallel and an optical delay line to obtain the quadrature condition. The generation of a 2-Gb/s QPSK signal is experimentally demonstrated, including a 1-km standard single-mode-fiber transmission.Journal of Lightwave Technology 12/2007; 25(11):3350-3357. DOI:10.1109/JLT.2007.907795 · 2.86 Impact Factor