function result=multipath(result0);
%新多徑
Fs=5000;
%r=input('請輸入傳數距離(km)(10,20,30,80）r=');
r=10;
%f0=input('請輸入中心頻率（kHz)(3或者5)f0=');
f0=1800;
multipath_cacu=[];       
switch r
    case 10
        %10km,5kHz信號,20ms保護時間
         multipath_cacu(:,1)=[0     0.01275   0.0068333]';
         multipath_cacu(:,2)=[1     0.62736     0.60346]';           
%           multipath_cacu(:,1)=[0     0.01275   0.0068333]';
%          multipath_cacu(:,2)=[1     0.62736     0.60346]';   
             
end       
multipath_cacu=sortrows(multipath_cacu,1);
[m_multipath,n_multipath]=size(multipath_cacu);

h=zeros(round(multipath_cacu(end,1))*Fs+1,1);
for i=1:m_multipath
    h(round(multipath_cacu(i,1)*Fs)+1)=multipath_cacu(i,2);
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% figure(4)
% t=(1:length(h))*1000/Fs;
% plot(t,h);
% legend('Multipath in time domain');

result=conv(result0,h);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% SL=194;
% switch f0
%     case 5
%         NL=54;
%     case 3
%         NL=56;
% end
% TL=20*log10(r*1000)+0.036*f0^(3/2)*r+15;
% SNR=SL-TL-NL-10*log10(Fs/2);
% %SNR=SL-TL-NL-10*log10(2000)%2000為帶寬