Getting Started

Setting the Symbol Period

To compare the cyclic code model to the BPSK model, which does not have channel coding, the ratio of energy per information symbol to noise spectral density, , should be the same in both models. You can use the Symbol period parameter in the AWGN Channel block to adjust the amount of channel noise so that is the same as in the model without coding. Since the cyclic code has rate 4/7, you set the Symbol period to 4/7.

In general, set the Symbol period to k/n if there are k information symbols for each n channel symbols. Both channel coding and modulation with more than two channel symbols require a change to the Symbol period.

Note that Es/No, the ratio of energy per channel symbol to noise spectral density, is not the same as . To convert between the two, use the formula

where k/n is the ratio of information symbols to channel symbols. Changing the Symbol period to k/n has the same effect as subtracting from the Es/No parameter.

Setting Parameters in the Cyclic Code Model

Using a Probe Block to Determine Symbol Period