Getting Started

Multirate Models

The model shown in the figure FSK Model differs from the earlier models in that it contains signals with different sample times. The Bernoulli Binary Generator block has a sample time of 1/1200. The M-FSK Modulator Passband block receives this signal and upsamples it at a rate of five samples per symbol. As a result, the sample time of the block's output signal is 1/6000. A model that contains signals with different sample times is called a multirate model.

The multiple sample times present in this model do not affect the bit error rate of a simulation. But you should be aware that in other models, sample times can affect the results of a simulation. This is usually the case when different signals are combined. See Setting Sample Times and Samples per Frame for an example of this.

Finding the Delay in the Model

Using Sample Time Colors to Check Sample Times