Long Haul Dispersion Managed Intensity Modulated Direct Detection Fiber Optic Communication Systems

OCSim Modules

Modern Fiber Optic Communication Systems Simulations with Advanced Level Matlab Modules

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Module 7

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Fiber Optic Transmission System Design

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Long Haul Dispersion Managed Intensity Modulated Direct Detection Fiber Optic

Communication Systems


Company Researchers & Developers

Integrate the Modules with your in-house and Commercial Software & Hardware Products

 

(1) Use the Existing Modules / Components for Your Research & Development.
(2) Modify the Modules / Components to the Next Level for Your Research & Development.
(3) Integrate Different Modules / Components in the OCSim Package to Realize Your Own Fiber Optic Communication Systems.
(4) Modify the Modules for Co-Simulations with the Third Party Commercial Optical Communication Systems Softwares.

 

Main Module

fiber_prop_linear_system.m

An intensity modulated direct detection (IMDD) fiber optic system is simulated. Gaussian pulses are used. Fiber dispersion and loss are taken into account, but fiber nonlinear effects are ignored. When the eye is nearly closed, Q-factor calculation may not be accurate.


This Module calls the following Sub Modules and Components:

(1) fiber.m
Signal spectrum is multiplied by the linear fiber transfer function (takes into account fiber loss and dispersion, but ignores nonlinear effects).

(2) amp.m
Here, amplifier provides the gain G and it adds noise whose PSD is given by Eq. (1) (see the manual). The amplifier noise is modeled as a white noise with Gaussian distribution. The amount of noise added can be changed by varying nsp.

(3) gauss.m
The optical receiver is modeled as a second order Gaussian filter. The bandwidth of the filter is deltf.

(4) eyediagram.m
This function plots the eye diagram.

(5) computeq.m
This function calculates the mean and variances of bit ’0’ and ’1’ and Q-factor.


Explore Further this Module:

7.1 Change the excess noise-factor n_{{sp}} from 1 to 10 and plot the Q-factor (or BER) versus n_{{sp}}. (Note: n_{{sp}} for practical amplifiers lie in the range of 1.5 to 5).

7.2 Let n_{{sp}} = 4. Change the Rx bandwidth delft from 0.4*B to 3*B where B is the bit rate. Find the optimum Rx bandwidth. Plot Q-factor as a function of Rx bandwidth.

7.3 Let n_{{sp}} = 1.5. Change the input power from -5 dBm to 5 dBm and plot the Q-factor (or BER) as a function of fiber launch power.

7.4 Let n_{{sp}} = 1.5. Remove the dispersion compensating fiber and study the performance (Q-factor or BER) as a function of dispersion coefficient (beta_{{2}}) of the transmission fiber, which ranges from -0.5 ps.ps/km to -22 ps.ps/km. To have a BER of 2X10-3, plot the maximum transmission distance as a function of dispersion coefficient.

7.5 In a dispersion managed fiber with full dispersion compensation, reduce the amplifier spacing by 4 and increase the number of amplifiers by 4 so that the total transmission distance is the same as before. Does the performance improve? Provide explanation.

7.6 Modify the source code so that the raised-cosine NRZ pulses are used in the electrical domain instead of Gaussian pulses. Repeat (i)-(v).

7.7 Design and simulate following IMDD fiber optic system links:

10 Gb/s, 40 span IMDD fiber optic system link
28 Gb/s, 20 span IMDD fiber optic system with inline dispersion compensation link
40 Gb/s, 20 span IMDD fiber optic system with inline dispersion compensation link
40 Gb/s, 20 span IMDD fiber optic system with dispersion managed fiber link
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n Gb/s, N span IMDD fiber optic system link
Choose the desired values of n and N for simulations.

Simulate more:

Switch on to Nonlinearity to design and simulate nonlinear IMDD fiber optic system links.

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Selected Simulated Results Using this Module 

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Long Haul Dispersion Managed Intensity Modulated Direct Detection (IMDD) Fiber Optic Communication Systems – Linear and Nonlinear

Consisting of a Transmitter, a Receiver, N Fibers (Standard and Dispersion Compensating) and N Amplifiers


Simulation Setup

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Input Power

(Long Haul Dispersion Managed Intensity Modulated Direct Detection (IMDD) Fiber Optic Communication Systems)

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Output Power

(Long Haul Dispersion Managed Intensity Modulated Direct Detection (IMDD) Fiber Optic Communication Systems)

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Receiver Current

(Long Haul Dispersion Managed Intensity Modulated Direct Detection (IMDD) Fiber Optic Communication Systems)

 

 

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Eye Diagram

(Long Haul Dispersion Managed Intensity Modulated Direct Detection (IMDD) Fiber Optic Communication Systems)

 

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OCSim Modules details can be seen by clicking the pages below:

OCSim Modules Overview | OCSim Modules (1-18) in the Package

Module (1a) | Module (1b) | Module (1c) | Module (2a) | Module (2b) | Module (2c) | Module (3a) | Module (3b) | Module (4a) | Module (4b) | Module (4c) | Module (4d) | Module (5) | Module (6a) | Module (6b) | Module (7) | Module (8a) | Module (8b) | Module (8c) | Module (9a) | Module (9b) | Module (10) | Module (11a) | Module (11b) | Module (12) | Module (13) | Module (14) | Module (15) | Module (16) | Module (17) | Module (18)


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OCSim Modules Selected Simulated Results | OCSim Modules Videos       

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