The main impediments for long distance signal transmission in the fibre optic system, especially the radio over fibre (RoF) system, are the chromatic dispersion and signal power attenuation. Additionally, the power consumption in the laser diode and optical amplifiers affect the signal transmission costs; however, it is lower than in a wireless system. Therefore, decreasing the power consumption and chromatic dispersion and increasing the data bit rate in RoF are the demands for present and future fibre optic system technology. In order to increase the signal transmission distance and improve the frequency spectrum, we study in this paper a mobile Worldwide Interoperability for Microwave Access (WiMAX) signal transmission over RoF via a triple symmetrical dispersion system. The combination of three different fibres - single mode fibre (SMF), dispersion compensating fibre (DCF) and chirped fibre Bragg grating (CFBG) - is used to transmit a 120Mbps mobile WiMAX scalable Orthogonal Frequency Division Multiple Access (OFDMA) signal with 3.5GHz carrier frequency and 20MHz bandwidth over a RoF system. To compensate the dispersion, the SMF and DCF are employed and specifically the high reflector CFBG is applied to reduce signal power loss. In our study, the WIMAX signal is transmitted through a triple symmetrical dispersion system consisting of 2xDCF (20 km) and 2xSMF (100 km) connected to SMF (24 km) and CFBG. Simulation results clearly indicate that the limited signal transmission length and data bit rate in the RoF system, caused by fibre attenuation and chromatic dispersion, can be overcome by the combination of SMF, DCF and CFBG. The transmission distance in the fibre is extended to 792 Km, SNR and OSNR are highly satisfactory; simultaneously the power consumption is decreased.
Inhaltsverzeichnis (Table of Contents)
- I. INTRODUCTION
- II. RELATED WORK
- III. THEORY AND ANALYSES
- A. Chromatic Dispersion
- B. Dispersion Compensating Fibre (DCF)
- C. Chirped Fibre Bragg Grating (CFBG)
- IV. SYSTEM DISCRIPTION OF WIMAX OVER ROF
- A. WiMAX Over RoF System Setup
- B. Mobile WiMAX Physical Layer
- C. Mach Zehnder Modulator (MZM)
- D. Triple Symmetrical Dispersion System
- V. SIMULATION RESULTS
- VI. CONCLUSION
Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)
This paper investigates methods to enhance the transmission distance of WiMAX signals over a Radio over Fiber (RoF) system, with the aim of reducing power consumption and achieving satisfactory Signal-to-Noise Ratio (SNR), Optical Signal-to-Noise Ratio (OSNR), and high-quality signal transmission spectrums.- Extended Mobile WiMAX signal transmission over RoF
- Chromatic dispersion and its effects on signal transmission
- Compensation techniques using Dispersion Compensating Fibre (DCF) and Chirped Fibre Bragg Grating (CFBG)
- Optimization of power consumption and signal quality in RoF systems
- Analysis of the triple symmetrical dispersion system for improved transmission distance
Zusammenfassung der Kapitel (Chapter Summaries)
- I. INTRODUCTION: This chapter introduces the growing interest in WiMAX systems and their advantages over existing mobile communication technologies. The challenges associated with high-frequency microwave signal distribution are discussed, highlighting the advantages of RoF systems in terms of reduced power consumption, noise, cost, and antenna size. The paper focuses on the use of a triple symmetrical dispersion system to enhance WiMAX signal transmission over RoF, including the combination of single-mode fiber (SMF), dispersion compensating fiber (DCF), and chirped fiber Bragg grating (CFBG).
- II. RELATED WORK: This chapter reviews existing research on RoF technology for WiMAX signal delivery, including studies on fiber length, attenuation, and EVM. It mentions various approaches to improve BER and signal transmission over different fiber link lengths.
- III. THEORY AND ANALYSES: This chapter delves into the theory of dispersion in fiber optic cables, focusing on chromatic dispersion, waveguide dispersion, and intermodal dispersion. The chapter explains how chromatic dispersion arises due to varying frequency components and analyzes the impact of SMF on signal transmission. It then introduces DCF and CFBG as compensation techniques for chromatic dispersion, highlighting their advantages and limitations.
- IV. SYSTEM DISCRIPTION OF WIMAX OVER ROF: This chapter provides a detailed description of the WiMAX over RoF system setup, including the dispersion model techniques (SMF, DCF, and CFBG), the base station (BS), and the radio access unit (RAU) antenna. The chapter explains the use of a Mach-Zehnder Modulator (MZM) for modulating the RF signal onto the laser beam and explores the advantages of using Femtocells in future WiMAX systems. The chapter also discusses the scalable orthogonal frequency division multiplexing (S-OFDMA) technique used in mobile WiMAX.
Schlüsselwörter (Keywords)
This paper focuses on the utilization of a triple symmetrical dispersion system to extend the transmission distance of mobile WiMAX signals over a RoF system. Key topics include chromatic dispersion compensation, power consumption optimization, and signal quality improvement. Techniques like Dispersion Compensating Fiber (DCF) and Chirped Fibre Bragg Grating (CFBG) are central to achieving this goal. The research also highlights the importance of scalable orthogonal frequency division multiplexing (S-OFDMA) and Mach-Zehnder Modulator (MZM) in the WiMAX over RoF system.- Citation du texte
- Mazin Al Noor (Auteur), Jonathan Loo (Auteur), Richard Comley (Auteur), 2011, Extended Mobile WiMAX Signal Transmission over RoF viaTriple Symmetrical Dispersion System SMF, DCF and CFBG, Munich, GRIN Verlag, https://www.grin.com/document/195645
