KEYWORDS: Free space optics, Antennas, Dense wavelength division multiplexing, Radio over Fiber, Modulation, Atmospheric optics, Radio optics, Televisions, Optical amplifiers, Single mode fibers
In this paper we present the design concept plus experimental results and evaluation of a newly developed
advanced DWDM Radio-on-Free-Space Optical (RoFSO) communication system capable of simultaneous transmission
of multiple RF signals. The RoFSO system is evaluated based on the performance metric parameters
defined for the various RF signals comprising of different wireless services including terrestrial digital broadcasting
signals, cellular 3GPP W-CDMA signals, IEEE 802.11 WLAN based signals etc being transmitted over the
RoFSO link. The performance metric parameters being considered include standard optical received power, CNR
and BER characteristics, W-CDMA signal transmission metric parameters like Adjacent Channel Leakage Ratio
(ACLR) and Error Vector Magnitude (EVM), modulation error ratio (MER) for digital terrestrial television
broadcasting signals as well as spectrum mask and EVM for IEEE 802.11 Wireless LAN signal transmission.
Radio on Free-Space Optics (RoFSO) communication systems have attracted a considerable attention for a variety of
applications where optical fibers are not feasible, especially in rural areas, to provide ubiquitous wireless services
quickly and more effectively. RoFSO links can be used to transmit signals like cellular W-CDMA, terrestrial digital TV
or WLAN signals. In spite of its potential, such links are highly dependent on the deployment environment
characteristics in particular the weather conditions. Severity and duration of the atmospheric effects have direct impact
on the availability of the links as well as on the quality of RF signal transmitted over it. Thus, the necessity of
investigating the effects of various weather conditions on RF signal transmission using FSO links.
In collaboration with several institutions, we are currently developing an advanced Dense Wavelength Division
Multiplexing (DWDM) RoFSO antenna capable of transporting multiple RF signals. As preliminary work, we are
conducting experiments on a 1 km link using an off-the-shelf Radio Frequency - FSO (RF-FSO) antenna, with the
objective of obtaining and characterizing performance related parameters of RF-FSO transmission in operational
environment. As an example, we examine the influence of atmospheric turbulence on the transmission quality of W-CDMA
signal. Among the performance metric of interest is the Adjacent Channel Leakage Power Ratio (ACLR) which
will be measured, analyzed and correlated with the weather conditions. An atmospheric fluctuation model for estimating
the communication quality of RF signal transmission on FSO links is being developed. Also the obtained results will be
used for the deployment environment characterization as well as baseline for the design and performance evaluation of
new advanced DWDM RoFSO communication systems we are currently developing.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.