The unique aspect of my work is that I will compare and analyze different systems to have a better knowing of the performance of each system. For example, I will

compare the performance of one system with a filter and without a filter. Most results of this project will be related to noise analysis, which will be presented in a form or arrangement to make comparison more convenient.

The rest of the report is pided into eight parts, which are technical approach, design rationale, result analysis, future work, conclusion, reference, and appendices. The technical approach will explain the characteristics of the technology used. The design rationale will provide the design’s details of this project. Result analysis is the focus of this project, which will include a selection of typical communication systems.

Related Work

Powerful computer’s ability makes it possible to simulate communication systems, and then greatly promoted the development of communication technology. The focus of this project is to study the modulation and demodulation of baseband and passband systems in order to understand the principles of communication systems.

The simulation software used in this project is Matlab and Simulink. This platform is very suitable for communication system learning because of its concise operation and rich functions. Matlab and Simulink can be used to build a hardware system model, providing a variety of simulation parameters that can verified and discover the solution.

The learning method of this project is to study the operation of different parts of different systems, to compare the performance of different systems, to compare the data of multiple simulations, and to compare the simulation values with theoretical values.

Systems simulated in this project include, but are not limited to, pulse amplitude modulation based on a random binary generator (Raised Cosine series signal, M-ary signal, rectangular signal.), quadrature amplitude modulation, eye diagrams, and phase locked loops.

The focus of the report is not how to simulate communication systems, but the

understanding of the communication systems, which is reflected in the design and results sections.

Technical Approach

Matlab and Simulink

Modern communication systems are designed by using simulation software, so simulation software can be considered as software brassboards.

Matlab and Simulink is such software, which provides a very efficient communication system simulation environment for students and developers.

Model windows and the Simulink Library Browserare are two main parts of Matlab and Simulink that have been used in the project.

Model Window

To create a blank model window you can click Simulink on the MATLAB home tab and choose a model template.

Figure 1 Blank Model Window

This is the workspace in which a system can be modeled and run.

Figure 2 Configuration Parameters

If you click on the gear icon you can open the interface, where you can set the running parameters. In this project, we often use fix-step time, start & stop time, etc. Then if you click the icon at the left side of the gear icon, you can open the Simulink Library Browser

Simulink Library Browser

Figure 3 Simulink Library Browser

All the blocks can be found at here and added to a Model, this is the core of Simulink. The following is a guide.

Libraries Pane

Use the libraries pane to locate blocks by navigating block libraries. The pane displays a tree view of the libraries installed on your system. You can navigate the tree using your mouse or keyboard. Use the arrow keys to move through the library and expand or collapse libraries. When you select a library, its contents appear in the blocks pane.

Blocks Pane

The blocks pane in the Library Browser displays the contents of the library selected in the libraries pane. You can use the blocks pane to navigate libraries, view block parameters or help, and create instances of library blocks in models.