Communications Blockset

Variables in the Model

When you load the model, it creates several variables, using the PostLoadFcn model callback parameter. Besides the variables N and M, there are:

• fr = frequency of the reference signal
• fq = quiescent frequency in the Voltage-Controlled Oscillator (VCO) block
• sen = Voltage-Controlled Oscillator input sensitivity

The model initially assigns values to these variables as follows: N = 10, M = 3, fr = 30 MHz, fq = 30 MHz and sen = 40 MHz/V. The frequency of the synthesized signal will then be 100 MHz. After running the simulation with these values, you can later change them by typing new values at the MATLAB prompt, if you want to experiment with the model.

Note    These are the same variables as those in the Fractional N-Frequency Synthesis demo, but they are assigned different initial values. If you change the values of these variables at the MATLAB command line, use the same upper and lower case letters in the variable names as given above.

PLL-Based Frequency Synthesis Demo

Running the Simulation