Comparison of M-ary PSK and M-ary QAM (Matlab 2012a)

Program:

 clc;
clear all;
n = input('Enter the number of values to be compared = ');
for i = 1:n;
    m = 2^i;
    r = (3/(m-1))/(2*(sin(pi/m))^2);
    rm = 10*log10(r);
    if(m==4)
        disp('QAM & PSK have comparable performance by = ');
    else
        disp('SNR of QAM is better than PSK by = ');
    end
    disp(rm);
end

Output:

Enter the number of values to be compared = 5
SNR of QAM is better than PSK by =
    1.7609

QAM & PSK have comparable performance by =
   9.6433e-16

SNR of QAM is better than PSK by =
    1.6531

SNR of QAM is better than PSK by =
    4.1953

SNR of QAM is better than PSK by =
    7.0213