Title page for etd-0721109-173808


[Back to Results | New Search]

URN etd-0721109-173808
Author Bo-hao Huang
Author's Email Address No Public.
Statistics This thesis had been viewed 5374 times. Download 1625 times.
Department Electro-Optical Engineering
Year 2008
Semester 2
Degree Master
Type of Document
Language English
Title Basic Study of Re-modulated Signal Quality for Fiber-to-the-home (FTTH)
Date of Defense 2009-07-08
Page Count 49
Keyword
  • FTTH
  • Re-modulated
  • Abstract 100Gbit/s transmission data rate is very attractive for the next generation Ethernet
    transport systems, and this kind of high-speed channel based WDM systems is very
    attractive for constructing cost-effective optical transport networks. However, it is
    quite difficult to achieve such high bit-rate by using the conventional amplitude shift
    keying (ASK) technology. For the subcarrier modulation of the orthogonal frequency
    division multiplexing (OFDM) scheme, it is possible to use various modulation
    formats. It is relatively easy to use such an advanced format in the microwave domain
    compared to the optical domain. Therefore, it is possible to increase the spectral
    efficiency relatively easily by using the OFDM technology. In this master thesis, 100
    Gbit/s WDM system with OFDM is discussed. The performance of 8 channels
    100Gbit/s OFDM system was evaluated. The simulation result showed that the BER
    of all channels were below 10-3 after 500 km transmission, and the performance could
    be improved by using the FEC. This result shows the possibility of 100Gbit/s
    transmission system using the OFDM technology.
    The major concern of WDM-PON system is the cost. For WDM-PON system, it
    needs several light sources for downstream signals and upstream signals. For the
    practical implementation of WDM-PON, it is essential to develop a low-cost light
    source in the optical network unit (ONU). In order to develop a simple efficient ONU,
    a promising solution is re-modulated the downstream signal from central office (CO)
    as the upstream signal at ONU using reflective semicounductor optical amplifier
    (RSOA) so that there is no need to setup an additional light source at the ONU side.
    For the conventional fiber-to-the-home (FTTH) system, the modulation format for
    both downstream signal and upstream signal is intensity modulation with direct
    detection (IM/DD). The demerit of the IM/DD scheme for the FTTH system is that
    the performance of the re-modulated upstream signal is limited by the interference of
    the downstream signal. In order to overcome this issue, the IM/DD format of
    downstream should be replaced by some different formats such as differential phase
    shift keying (DPSK). As there is no amplitude modulation for the DPSK downstream
    signal, the re-modulated signal will not be affected by the downstream signal.
    Therefore, this master thesis is focusing on comparing the re-modulated signal quality
    for both IM/DD downstream and DPSK downstream. The experimental results shows
    that the upstream signal of the DPSK downstream case shows better performance than
    the IM/DD downstream case, and the performance difference of the re-modulated
    signal is 17dB.
    Advisory Committee
  • Wood-Hi Cheng - chair
  • Chin-Ping Yu - co-chair
  • Hung-Wen Chang - co-chair
  • Hidenori Taga - advisor
  • Files
  • etd-0721109-173808.pdf
  • indicate access worldwide
    Date of Submission 2009-07-21

    [Back to Results | New Search]


    Browse | Search All Available ETDs

    If you have more questions or technical problems, please contact eThesys