Department of Electricaland
Computer Systems Engineering
Technical ReportMECSE-4-2005
DWDM Optically Amplified Transmission Systems - SIMULINKModels and Test-Bed: Part III DPSK
L.N. Binh and Y.L.Cheung
L.N. Binh and D. Wong ECSE Monash university 2005
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DWDM OPTICALLY AMPLIFIED TRANSMISSION SYSTEMS -
SIMULINK MODELS AND TEST-BED: PART III DPSK
MODULATION FORMAT
L.N. Binh and D. Wong
Department of Electrical and Computer Systems Engineering, Monash University,
Clayton, Victoria 3168 Australia email; [email protected]
Abstract
A simulator based on Matlab Simulink for simulation of optical communication
systems employing DPSK modulation format and RZ and NRZ pulse profile is
described. The simulator for optically amplified transmission systems (SOATS) is
described in details with simulink blocks and monitored with several scopes.
The choice modulation format used is very important to minimize the fiber
dispersion and impairments due to nonlinear effects. Dispersion can be
compensated with the use of dispersion compensating fibers. Experimental set-up
and results are included and compared with simulated system performance.
Simulink blocks of the simulator system design are described, conferred and
proven with experimental results. Various modulation formats developed for the
Simulink simulator are also described. Experimental results are confirmed with
analytically simulated results. Phase modulation formats have been considered
and implemented using MATLAB SIMULINK. The NRZ, RZ, NRZ-DPSK and RZ-
DPSK transmission and demodulation are designed and demonstrated. This
MatLab Simulink model allows simulation of novel advanced optical
communications systems.
MECSE-4-2005: "DWDM Optically Amplified Transmission Systems - SIMULINK ...", L.N. Binh and Y.L.Cheung
L.N. Binh and D. Wong ECSE Monash university 2005
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CONTENTS
Abstract ............................................................................................................................... 1
1. INTRODUCTION ...................................................................................................... 7
2. TRANSMISSION SYSTEMS AND PHOTONIC COMPONENTS......................... 8
2.1. Transmission Systems......................................................................................... 8
2.2. The Mach-Zehnder Interferometer Modulator.................................................... 9
2.3. Modulation........................................................................................................ 10
2.4. Optical Fibers.................................................................................................... 11
2.5. Optical Receivers .............................................................................................. 12
3. EXPERIMENTAL SETUP AND RESULTS........................................................... 12
3.1. Equipment and Photonic Hardware .................................................................. 13
3.2. Experimental Results ........................................................................................ 19
3.2.1 Observation of the sidebands of the MZIM.............................................. 19
3.3. The Vbias of the MZIM ...................................................................................... 21
3.3.1 The BER of the MZIM ............................................................................. 23
4. The SIMULINK SIMULATOR ............................................................................... 31
4.1. Design Process .................................................................................................. 31
4.2. NRZ Transmitter............................................................................................... 32
4.2.1 Non-Return to Zero (NRZ) ....................................................................... 32
4.2.2 10G/bits MZIM block............................................................................... 35
4.2.3 RF Voltage block ...................................................................................... 36
4.2.4 Data Selection block ................................................................................. 37
4.2.5 V_bias Effect Block.................................................................................. 37
4.2.6 Results....................................................................................................... 38
4.3. NRZ-OOK Transmitter with 80km Single Mode Fiber (SMF) and Dispersion
Compensation Module (DCM) ..................................................................................... 39
4.4. NRZ-OOK Transmitter with 80km Dispersion Shifted Fiber (DCF)............... 42
4.5. NR-OOK Transmitter with Demodulation ....................................................... 44
4.5.1 NRZ block................................................................................................. 45
4.5.2 Phase Shift Block...................................................................................... 46
MECSE-4-2005: "DWDM Optically Amplified Transmission Systems - SIMULINK ...", L.N. Binh and Y.L.Cheung
L.N. Binh and D. Wong ECSE Monash university 2005
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4.5.3 Demodulation block.................................................................................. 46
4.5.4 Results....................................................................................................... 48
4.6. RZ Transmitter with Demodulation.................................................................. 50
4.6.1 MZIM-2 block .......................................................................................... 51
4.6.2 Results....................................................................................................... 52
4.7. NRZ DPSK Simulator Model ........................................................................... 54
4.7.1 DPSK block .............................................................................................. 57
4.7.2 PM block................................................................................................... 57
4.8. RZ Differential Phase Shift Keying (DPSK) Model......................................... 60
5. CONCLUDING REMARKS and CHALLENGES.................................................. 62
6. REFERENCES ......................................................................................................... 64
TABLE OF FIGURES
Figure 1: General optically amplified communication system diagram ............................ 8
Figure 2: Mach-Zehnder (a) configuration and operation.[2] (b) The V-P transfer
characteristics of the Mach-Zehnder modulator. ..................................................... 10
Figure 3: Block diagram of an optical digital receiver[2]............................................... 12
Figure 4: Optical Spectrum Analyzer ............................................................................... 13
Figure 5: Series Spectrum Analyzer.................................................................................. 13
Figure 6: Power Supply .................................................................................................... 14
Figure 7: Pulse Pattern Generator ................................................................................... 14
Figure 8: Synthesized Signal Generator (10MHz to 20GHz) ........................................... 14
Figure 9: Current-Limited Power Supply ......................................................................... 15
Figure 10: Digital Communications Analyzer.................................................................. 15
Figure 11: 12GHz IR Photo Receiver............................................................................... 16
Figure 12: Tunable Laser Source MG9638A ................................................................... 16
Figure 13: Experimental Setup ......................................................................................... 17
Figure 14: Mach-Zehnder Interferometer Modulator ...................................................... 18
Figure 15: Polarization Controller ................................................................................... 18
Figure 16: Coupler ........................................................................................................... 19
Figure 17: Tunable Dispersion Compensator................................................................... 19
MECSE-4-2005: "DWDM Optically Amplified Transmission Systems - SIMULINK ...", L.N. Binh and Y.L.Cheung
L.N. Binh and D. Wong ECSE Monash university 2005
4
Figure 18: Frequency spectrum generated with (a) 3.3GHz sinusoidal waveform (b)
4.3GHz( c) 5.3GHz . ................................................................................................. 20
Figure 19: Frequency spectrum generated with (a) 6.3GHz sinusoidal waveform (b)
7.3GHz. ..................................................................................................................... 21
Figure 20: Measured MZIM characteristics (a) Driven voltage versus power in dBm (b)
in linear scale.......................................................................................................
