function [data_out,Gain]=rayleigh_chan(Ts,data_in,A)


    gain_linear=10^(A/10);
    Gain=gain_linear*(randn(1,1)+j*randn(1,1))/2;
    data_temp(ii)=data_in*Gain;   
    
    
    L=20;
    Tao=0.7e-6;
    for kk=1:N    
        Mid=round(Tao/Ts);
        Low=Mid-L/2;
        High=Mid+L/2;
        tempii=0;
        for ii=Low:High
            temp=pi*(ii-Tao(nn)/Tsap+1e-30);
            if ((kk-ii)>0)&&((kk-ii)<N+1)
            tempii=tempii+ x(kk-ii)*sin(temp)/(temp);
            end
        end        
        yy(kk)=yy(kk)+exp(j*Phn(nn)+j*2*pi*Fd(nn)*kk*Tsap)*tempii;
    end