Communications System Toolbox

System Design, Characterization, and Visualization

The design and simulation of a communications system requires analyzing its response to the noise and interference inherent in real-world environments, studying its behavior using graphical and quantitative means, and determining whether the resulting performance meets standards of acceptability.

Communications System Toolbox implements a variety of tasks for communications system design and simulation. Many of the functions, System objects™, and blocks in the system toolbox perform computations associated with a particular component of a communications system, such as a demodulator or equalizer. Other capabilities are designed for visualization or analysis.

System Characterization

The system toolbox offers several standard methods for quantitatively characterizing system performance:

• Bit error rate (BER) computations
• Adjacent channel power ratio (ACPR) measurements
• Error vector magnitude (EVM) measurements
• Modulation error ratio (MER) measurements

Because BER computations are fundamental to the characterization of any communications system, the system toolbox provides the following tools and capabilities for configuring BER test scenarios and accelerating BER simulations:

BERtool — A graphical user interface that enables you to analyze BER performance of communications systems. You can analyze performance via a simulation-based, semianalytic, or theoretical approach.

Error Rate Test Console — A MATLAB object that runs simulations for communications systems to measure error rate performance. It supports user-specified test points and generation of parametric performance plots and surfaces. Accelerated performance can be realized when running on a multicore computing platform.

Multicore and GPU acceleration — A capability provided by Parallel Computing Toolbox™ that enables you to accelerate simulation performance using multicore and GPU hardware within your computer.

Distributed computing and cloud computing support — Capabilities provided by Parallel Computing Toolbox and MATLAB Distributed Computing Server™ that enable you to leverage the computing power of your server farms and the Amazon EC2 Web service.

Performance Visualization

The system toolbox provides the following capabilities for visualizing system performance:

Channel visualization tool — For visualizing the characteristics of a fading channel

Eye diagrams and signal constellation scatter plots — For a qualitative, visual understanding of system behavior that enables you to make initial design decisions

Signal trajectory plots — For a continuous picture of the signal's trajectory between decision points

BER plots — For visualizing quantitative BER performance of a design candidate, parameterized by metrics such as SNR and fixed-point word size

Communication-specific displays for visualizing and analyzing signals at any point or step in your model. Displays include (clockwise from top left): Channel impulse response history, I/Q signal eye diagrams, BER performance plot for theoretical vs. simulated results, and received signal scatter plot.