Faculty of Engineering and Information Science
BACHELOR OF ENGINEERING DEGREE/DEGREE WITH HONOURS IN ELECTRICAL AND ELECTRONIC ENGINEERING
NONLINEAR EFFECT OF DIRECT SEQUENCE-CDMA IN OPTICAL TRANSMISSION
20 April 1998
ABSTRACT
Subcarrier Multiplexing (SCM) technology is used to link the Base Station to the Central Station through optical fiber. But a major problem associated with optical SCM, is the Nonlinearity of the Laser Diode(LD). The aim of this report is to provide the reader with a working knowledge of the Intremodulation Distortion (IMD) due to Laser Diode (LD) non-linearity of an asynchronous Direct Sequence Code Division Multiple Access (DS/CDMA) systems in optical transmission. A third-order polynomial without memory is used to present LD Nonlinearity. In DS/CDMA system only one harmonic of the third-order Intermodulation term falls on the signal frequency band and influences the system performance. We can evaluate the effect of the Nonlinearity on the SCM transmission of CDMA signals. We find that the Nonlinearity of the Laser diode being a Compressing (where a<0 ) or an expanding one(where a<0 ). In the case of the LD being an expanding one the degradation is not dramatic whereas for the LD being a Compressing significant performance degradation may occur.
TABLE OF CONTENTS
Abstract
Acknowledgments
Chapter 1. General information
Chapter 2. Spread Spectrum Systems
- 2.1 Introduction
- 2.2 Basic principle of Spread Spectrum
- 2.3 Advantages of Spread Spectrum
- 2.4 Disadvantages of Spread Spectrum
- 2.5 Spread Spectrum Techniques
Chapter 3. Multiple Access Techniques
- 3.1 Introduction
- 3.2 Time Division Multiple Access (TDMA)
- 3.3 Frequency Division Multiple Access (FDMA)
- 3.4 Carrier Sense Multiple Access (CSMA)
- 3.5 Code Division Multiple Access (CDMA)
- 3.6 Comparison Of CDMA, FDMA, TDMA
Chapter 4. Laser diodes
Chapter 5. Optical Links For Mobile CDMA Networks
Chapter 6. Intermodulation Distortion for CDMA Signals
Chapter 7. Numerical Results
Chapter 8. Conclusions
Chapter 9. Future Work
Bibliography
References
Appendix 1.
 |
Created and maintained by
Panayiota Shiama Last updated on : March 2003 |
