OOFDM Signal Transmission Using a Single Optical Broadband Source

Abstract

In this paper, optical OFDM signal transmission is demonstrated by using a broadband optical source over a 10 km fiber link. OFDM signal transmission usually employs lasers to generate the optical carrier since the chromatic fiber dispersion prevents the use of broadband optical sources. However, an interferometric system is introduced to allow signal transmission at a given RF band when a broadband optical source is employed. Optical sources with different optical bandwidths have been employed to explore the limitations of the system. OFDM transmission at 2 Gb/s using both QPSK and 16QAM modulation is demonstrated over 10 km.

Bidirectional WDM-OOFDM access network based on a sliceable optical transceiver with colorless ONUs

“…Furthermore, as claimed in [22], this system is free of the power fading penalty due to chromatic dispersion on the spectral region where RF bandpass transmission signal is opened, even when DSB conventional scheme is employed. This fact also simplifies the modulation stage when compared to single-sideband (SSB) modulated signals usually employed to overcome power fading.…”

“…DL and UL signals employ different frequency bands, which are selected by the proper configuration of both detection stages. The detection stage required for optical OFDM signal transmission using optical broadband sources is based on the use of a tunable Mach-Zehnder interferometer (TMZI) and a PIN photodiode [22], as will be briefly explained below. Fig.…”

“…It confirms the generation of a new transmission bandpass at 5 GHz, with a 3 dB bandwidth of 0.95 GHz, as a result of inserting the TMZI in the ONU, and losses of 10.5 dB respect to baseband. Full characterization of such transmission system can be found in [22,24], where the bandwidth of the electrical response is obtained in terms of the optical bandwidth and accumulated dispersion. The network was tested with a 0.9 Gb/s 16-QAM OFDM downlink signal with 750 MHz bandwidth.…”

“…More recently, the utilization of a tunable Mach-Zehnder interferometer (TMZI) allowed to demonstrate an OOFDM access network based on a single optical broadband source (BBS) to transmit moderate bitrates with low cost, high stability, low crosstalk operation [22] and also allowing multiband OFDM transmission in WDM networks [23]. A theoretical analysis in [24] details the potential of this optical BBS-based transmission system over a radio frequency band, also free from carrier suppression effect for any amplitude modulation format.…”

Broadband Optical Sources for Low-Cost WDM-MB-OFDM Networks

“…Multicarrier sources based on external cavity [14], semiconductor mode-locked lasers [16], or distributed feedback lasers [12], amongst others [17], have demonstrated good performance in DD-OFDM systems. However, optical broadband sources would be an interesting solution for moderate bitrate OOFDM access networks [18]. They offer a low-cost option, high stability, low cost operation and the possibility to transmit RoF signals [19].…”