MATLAB TUTORIALS-1

                         A Sinusoidal Wave Implementation

                                     And Analyzer

In this section, we will quickly start analyzing signals in time and frequency domains. Of course, knowing and applying math in the simulation environment are the key point of understanding. Therefore, this material represents only one side of the equation. 

 The theoretical spectrum, 𝑋(𝑓) of 𝑥(𝑡) = 𝐴𝑐𝑜𝑠(2𝜋𝑓𝑐 𝑡) is

                                             𝑋(𝑓) = 𝐴^2 𝛿(𝑓 − 𝑓𝑐 ) + 𝐴^2 𝛿(𝑓 + 𝑓𝑐 )

 and its power spectral density (PSD), 𝑆𝑥 (𝑓), 

                                              is 𝑆𝑥 (𝑓) = 𝐴^2/4 𝛿(𝑓 − 𝑓𝑐 ) + 𝐴^2/4 𝛿(𝑓 + 𝑓𝑐 )

1. The example presented here with A=1, fc=100Hz.
2. Therefore, the peak value of the spectrum is ½ or -3Db.
3.  The average power is A2 /2=0.5
4.  The peak of the power spectrum is A2 /4=1/4 and is expressed in dBW as 10log(1/4) = −6dBW. 
5. The Simulink Model is expressed in the reference

double click on the block to changes the properties of that particular block as shown in below

then according to your signal sampling choose the buffer size and length of the FFT transform.after completely followed this step simulate the design getting result like as shown below,