TY - JOUR
T1 - Direct and External Intensity Modulation in OFDM RoF Links
AU - Khwandah, Sinan A.
AU - Cosmas, John P.
AU - Glover, Ian A.
AU - Lazaridis, Pavlos I.
AU - Prasad, Neeli R.
AU - Zaharis, Zaharias D.
PY - 2015/8/1
Y1 - 2015/8/1
N2 - Radio-over-fiber (RoF) systems comprise light modulation and transmission of millimeter-wave signals over fiber links. The aim of this study is to investigate the performance of external and direct intensity modulation in RoF links and to analyze the drawbacks induced by different components of the optical system. In external modulation, the Mach-Zehnder modulator (MZM) is used, whereas the vertical-cavity surface-emitting laser (VCSEL) is utilized in direct modulation. Both modulation schemes are tested for a vector modulation format, i.e., the quadrature amplitude modulation (QAM), where an orthogonal frequency-division multiplexing (OFDM) scheme is used to generate signal subcarriers. The simulations are carried out with the same values of common global parameters for both schemes of intensity modulation. Although VCSEL is a promising device for future RoF systems, the external modulation shows a more robust performance compared with that of VCSEL when implemented with the OFDM modulation technique.
AB - Radio-over-fiber (RoF) systems comprise light modulation and transmission of millimeter-wave signals over fiber links. The aim of this study is to investigate the performance of external and direct intensity modulation in RoF links and to analyze the drawbacks induced by different components of the optical system. In external modulation, the Mach-Zehnder modulator (MZM) is used, whereas the vertical-cavity surface-emitting laser (VCSEL) is utilized in direct modulation. Both modulation schemes are tested for a vector modulation format, i.e., the quadrature amplitude modulation (QAM), where an orthogonal frequency-division multiplexing (OFDM) scheme is used to generate signal subcarriers. The simulations are carried out with the same values of common global parameters for both schemes of intensity modulation. Although VCSEL is a promising device for future RoF systems, the external modulation shows a more robust performance compared with that of VCSEL when implemented with the OFDM modulation technique.
KW - direct intensity modulation
KW - external intensity modulation
KW - Mach-Zehnder modulator (MZM)
KW - optical orthogonal frequency-division multiplexing (OFDM)
KW - Radio-over-fiber (RoF)
KW - vertical-cavity surface-emitting laser (VCSEL)
UR - http://www.scopus.com/inward/record.url?scp=84938704913&partnerID=8YFLogxK
U2 - 10.1109/JPHOT.2015.2456499
DO - 10.1109/JPHOT.2015.2456499
M3 - Article
AN - SCOPUS:84938704913
VL - 7
JO - IEEE Photonics Journal
JF - IEEE Photonics Journal
SN - 1943-0655
IS - 4
M1 - 7158985
ER -