Optical Distribution of OFDM and Impulse-Radio UWB in FTTH networks R. Llorente (1) , T. Alves (2) , M. Morant (1) , M. Beltran (1) , J. Perez (1) , A. Cartaxo (2) , J. Marti (1) (1) Fibre-Radio Group, Nanophotonics Technology Centre, Universidad Politécnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain (2) Optical Communications Group, Instituto de Telecomunicações, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal E-mail: rllorent@dcom.upv.es Abstract: Proposal, experimental demonstration and performance comparison of impulse-radio UWB and OFDM UWB distribution in FTTH networks for high-definition audio/video broadcasting is presented. OFDM-UWB exhibits better performance compared with its impulse- radio counterpart with better spectral efficiency. ©2007 Optical Society of America OCIS codes: (060.0060) Fiber optics and optical communications, 1. Introduction Ultra-Wide Band (UWB) technology is receiving a lot of attention, in particular in the US and in Europe due to its unique features: low self-interference, tolerance to multi-path fading; low probability of interception and capability of passing through walls while maintaining the communication [1]. UWB is being introduced in the market for high bitrate high definition (HD) in picocell range replacing HD cabling [2]. This paper proposes the distribution of high bitrate multimedia content in fiber-to-the-home (FTTH) networks employing UWB signals. This approach is depicted in Fig. 1: UWB signals are generated at a central node (Head-End) and are distributed on fiber to a number of subscribers. At the subscriber premises, the UWB-on-fiber signal is photodetected, filtered, amplified (O/E block in Fig.1) and radiated (antenna block in Fig.1) to broadcast HD content to an UWB-enabled TV set or computer. This approach combines UWB advantages with the economy and bandwidth (BW) capacity of FTTH networks. This is advantageous over other distribution networks, like hybrid fiber-coax (HFC), because no trans-modulation of frequency up-conversion stages are required at the subscriber premises, leading to lower deployment cost. UWB is defined as a radio modulation technique with a minimum bandwidth of 500 MHz or at least 20% greater than the centre frequency of operation. UWB signals are allocated in band between 3.1 to 10.6 GHz with -41.3 dBm/MHz equivalent isotropic radiated power (EIRP) and in the 1.99 to 3.1 GHz with -51 dBm/MHz EIRP, as in FCC part 15 [3]. Two UWB implementations are mainstream: (A) Impulse-Radio UWB (IR- UWB) transmits data by short impulses (monopulses) achieving data rates over 1 Gbit/s @ 10 m [4]. (B) The OFDM-UWB approach divides the spectrum (3.1 to 10.6 GHz) into 14 bands 528-MHz wide. Each band bears 128 carriers PSK modulated achieving 53 Mbit/s @10 m to 480 Mbit/s @3 m [5]. Range extension over 30m including MIMO processing has been recently proposed [6] which would enable UWB distribution of HD video covering a whole home or office. O/E Antenna O/E Antenna O/E Antenna HFC network UWB UWB Head End FTTH UWB on fibre UWB on fibre UWB on fibre Figure 1. UWB on fibre to distribute high bitrate multimedia concept. O/E Antenna O/E Antenna O/E Antenna HFC network UWB UWB Head End FTTH UWB on fibre UWB on fibre UWB on fibre Figure 1. UWB on fibre to distribute high bitrate multimedia concept. 2. Proof of concept demonstration set-up Fig. 1 shows the experimental proof-of-concept setup. This setup evaluates 1.25 Gbit/s UWB –adequate for HD video- transmission on different FTTH fibers up to 60km paths from a ”Head-End” (Fig.1) to the user premises [7]. a2160_1.pdf JWA109.pdf OFC/NFOEC 2008 978-1-55752-855-1/08/$25.00 ©2008 IEEE