Getting Started

Setting Parameters in the Cyclic Code Model

Make the following changes to the parameter settings for the BPSK model, described in Setting Parameters in the BPSK Model:

1. Double-click the Bernoulli Binary Generator block and make the following changes to the default parameters in the block's mask.
• Check the box next to Frame-based outputs.
• Set Samples per frame to 4 to match the input requirement of the Binary Cyclic Encoder Block.
2. Double-click the Binary Cyclic Encoder block and set Codeword Length N to 7. Make the same change in the Binary Cyclic Decoder block.
3. Double-click the AWGN Channel block and make the following changes to the default parameters in the block's mask.
• Set Symbol period to 4/7. With this setting, the AWGN channel block produce the same amount of noise per symbol as in the BPSK model without coding. This enables you to evaluate the improvement in bit error rate due to channel coding. For more information on setting Symbol period, see Setting the Symbol Period.
• Set Es/No to 4.2.

Running the Cyclic Code Model

When you run the model, the bit error rate is approximately one tenth the error rate in the model shown in the figure BPSK Modulation Model, which does not have channel coding.

Double-click the AWGN Channel block and change Es/No to 2.05. Now when you run the model, the bit error rate is approximately the same as that in the BPSK model. This means that the coding gain from the cyclic code at this bit error rate is 4.2 - 2.05 = 2.15 dB.

Building the Cyclic Code Model

Setting the Symbol Period