Distortion of OFDM Signals on Radio-Over-Fiber Links Integrated With an RF Amplifier and Active/Passive Electroabsorption Modulators

• Published in: Journal of lightwave technology 2008-03, Vol.26 (5), p.467-477
• Main Authors: Ju Bin Song, Islam, A.H.M.R.
• Format: Article
• Language: English
• Subjects: Adjacent channel power ratio (ACPR); Amplifiers; Analytical models; Applied sciences; Broadband; Broadband communication; Circuit properties; Distortion; Distortion measurement; Distributed feedback devices; Electric, optical and optoelectronic circuits; Electronics; error vector magnitude (EVM); Exact sciences and technology; Information, signal and communications theory; Integrated optoelectronics. Optoelectronic circuits; IP networks; Links; Mathematical analysis; Multiplexing; Networks; Nonlinear distortion; Nonlinearity; OFDM modulation; Optical and optoelectronic circuits; Optical fiber communications; Optical telecommunications; Orthogonal Frequency Division Multiplexing; orthogonal frequency division multiplexing (OFDM) signals; passive electroabsorption modulator; Peak to average power ratio; peak-to-average power ratio (PAPR); Radio frequencies; radio-over-fiber (RoF); Radiofrequency amplifiers; RF signals; Signal and communications theory; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Wireless networks
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2007.915213

The integration of orthogonal frequency division multiplexing (OFDM) and radio-over-fiber (RoF) techniques have made cost-effective and high-data-rate mobile wireless Internet networks possible, such as wireless broadband networks. This paper describes the distortion effects of OFDM signals fed via an RF amplifier integrated with an RoF link employing active and passive electroabsorption modulators (EAM) for chiefly broadband in-building network applications. First, peak-to-average power ratio was investigated for RoF links. Second, the adjacent channel power ratio, which estimates the degree of spectral re- growth due to the in-band and out-of-band interference resulting from distortion effects from nonlinear amplification, error vector magnitude, and system distortion effects, was also observed for the proposed system. In this study, we considered a combined Volterra-series and impulse response-based analytical model for WiBro systems and compared it to the observed measurements. We analyzed the different nonlinear distortion effects for OFDM signals driven via an RF amplifier that was integrated with an RoF link employing a distributed feedback laser as a transmitter and an active and passive InP EAM as a receiver. The results show significant agreement between the suggested analytical model and the measurement case. This study is unique in that it examines the distortion effects of RoF links with active and passive EAMs as an access point for OFDM-based wireless access networks.