Intermodulation Distortion Improvement for Fiber-Radio Applications Incorporating OSSB+C Modulation in an Optical Integrated-Access Environment

• Published in: Journal of lightwave technology Vol. 25; no. 6; pp. 1602 - 1612
• Main Authors: Lim, C., Nirmalathas, A., Ka-Lun Lee, Novak, D., Waterhouse, R.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.06.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Carriers; Channels; Circuit properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Fiber nonlinear optics; Fiber-wireless; Integrated optics; Integrated optics. Optical fibers and wave guides; Intermodulation distortion; Linearity; linearization; Merging; microwave photonics; Modulation; Noise levels; Nonlinear optical devices; Nonlinear optics; Optical and optoelectronic circuits; Optical components; Optical devices; Optical distortion; Optical modulation; optical single sideband modulation; Optical telecommunications; Radio frequency; Simulation; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Wireless communications; Wireless optical communications; Integrated optics; Fiber-wireless; Optical component; Intermodulation distortion; Radio wave; Optical telecommunication; Third order; Wireless telecommunication; Transmission channel; Microwave; Base band; Single carrier; Millimetric wave; Free space propagation; Simulation; Linearity; optical single sideband modulation; Optical modulation; Free space optics; Microwave photonics; Radio communication; Single sideband; Light dispersion; Linearization
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2007.896814

In this paper, we investigate the reduction of intermodulation distortion (IMD) in fiber-radio systems incorporating a dispersion-tolerant optical single sideband with carrier modulation. We present a systematic analysis and quantification of the third-order IMD generated due to optical components in the nonlinear optical front-end. Our proposed technique to improve the optical front-end linearity is by the removal of the optical components that contribute most to the third-order IMD in the RF domain. We experimentally demonstrated the proposed technique with two- and three-tone tests and showed more than 9-dB improvement in the overall carrier-to-IMD ratio. The proposed technique was also investigated via simulation analysis for a larger number of radio channels and showed an IMD suppression of >10 dB. In addition, the proposed technique is not only able to improve the carrier-to-interference of the radio signals but also to enable simultaneous baseband transmission, thereby facilitating the merging of millimeter-wave fiber-radio systems with other wired-access infrastructure. We present a detailed investigation and characterization of this technique.