Communications Blockset

Punctured Convolutional Coding Demo

The complexity of a Viterbi decoder increases rapidly with the code rate. Puncturing is a technique that allows the encoding and decoding of higher rate codes using standard rate 1/2 encoders and decoders. This example, tstconvcod, demonstrates how to use the Convolutional Encoder and Viterbi Decoder blocks to simulate a punctured coding system.

The example is somewhat similar to the one that appears in Example: Soft-Decision Decoding, which demonstrates convolutional coding without puncturing. The present example contains two blocks related to puncturing: Puncture and Insert Zero.

This description of the demo includes these topics:

• Structure of the Demo
• Generating Random Data
• Convolutional Encoding
• Puncturing
• Transmitting Data
• Demodulating
• Inserting Zeros
• Viterbi Decoding
• Calculating the Error Rate
• Evaluating Results
• Bibliography

Demonstration Models

Structure of the Demo