write an equation with graph

Hello, I need help with writing an equation that has 3 parameters in Matlab and plot the graph of it.

The equation is : Rb= SF * CR* BW/2^SF (bit/sec)

the x-axis is for time and the y-axis is for bits

I want to change the values of 2 parameters and make one stable and see the difference.

any help please ??

[Sriram Tadavarty]

Hi Diana,

Can you inclde what the values of SF, CR, BW are? It would be easy to share what you have tried so far and where did you struck? What are the inputs and expected outputs?

Regards,

Sriram

[Diana Kh]

Hi Sriram,

The inputs and their values are :

Spreading factor SF=7,8,9,10,11,12

Code rate CR=1,2,3,4

Bandwidth BW=125,250,500 KHz .

The output name is bit rate Rb and its unit (bit/sec). I want to change the values of 2 parameters and make one stable and see the difference.

hope I have explained it well

Answer 1

[Chenguang Yan]

This might help you:

SF = [7,8,9,10,11,12];
CR = [1,2,3,4];
BW = [125,250,500];
BW_fixed = BW(1);    % fixed Bandwidth

[X_SF,Y_CR] = meshgrid(SF,CR);
Rb= X_SF.*Y_CR.* BW_fixed./2.^X_SF;
surf(X_SF,Y_CR,Rb)