i want to make MMSE Equalizer and got this code... can someone explain the function of this code per line?

H = comm.PSKModulator(8,pi/8,'BitInput',false);
Hdemod = comm.PSKDemodulator(8,pi/8,'BitOutput',false);
n=9;  
r_data = randint(n,1); 
data_psk=[];
data_psk = step(H,r_data); 

d1=data_psk(1);
d2=data_psk(5);

data_psk(1) = 0.7071+0.7071i; 
data_psk(5) = 0.8660+0.8660i;

dawgn=awgn(data_psk,0); % Adding white Gaussian Noise

est(1)=dawgn(1);
est(2)=dawgn(5);

% MMSE starts here......
des=[0.7071+0.7071i 0.8660+0.8660i];
rec=[est(1) est(2)]; 
z=filter([1 0 0 0 0 0 0 0],[1],rec);
Rxx=xcorr(rec);
Rxz=xcorr(des,z);
x=toeplitz([Rxx zeros(1,5)],zeros(1,8))
cof=x\([Rxz zeros(1,5)].'); 

det1=filter(cof,[1],dawgn);
det1

for i=1:8
det(i)=filter(cof,[1],dawgn(i));
end
det.'