% predistorter.m
% adaptive predistortion in OFDM signal
function [out2_an,out2_pn,table_an,table_pn,table_indicate]=predistorter(in_an,in_pn,table_an,table_pn,table_indicate)
in_amax=0.7;
in_an=in_an/in_amax;
n=length(in_an);
address=ones(1,n);
cap=512;
for i=1:n
    in_ani=in_an(i);
    in_pni=in_pn(i);
    address_i=address(i);
    [address_i,in_ani]=Q(in_ani);% Q: adrress function
    out_ani=in_ani*table_an(address_i);
    out_pni=in_pni+table_pn(address_i);
    [out2_ani,out2_pni]=HPA(out_ani,out_pni); % HPA:high power amplifer function
    [table_an,table_pn]=LUT(address_i,table_an,table_pn,table_indicate,in_ani,in_pni,out2_ani,out2_pni);% LUT: look up table renew function
    out2_an(i)=out2_ani;
    out2_pn(i)=out2_pni;
    address(i)=address_i;
end