parameter_gaussian.m

Suzuki信道仿真,用于多路径信道衰落.综合大尺度衰落和小尺度衰落.可用来仿真频率选择性衰落以及时间选择性衰落.

function[f_i,c_i,theta_i]=Parameter_Gaussian(Method_type,N_i,Variance,fc,kc,phase)
sigma=sqrt(Variance);
if strcmp(Method_type,'MED')==1
    n=(1:N_i)';
    f_i=kc*fc/(2*N_i)*(2*n-1);
    c_i=sigma*sqrt(2)*(sqrt(erf(n*kc*sqrt(log(2))/N_i)-erf((n-1)*kc*sqrt(log(2))/N_i)));
elseif strcmp(Method_type,'MEA')==1
    n=(1:N_i)';
    f_i=fc/sqrt(log(2))*erfinv(n/N_i);
    f_i(N_i)=fc/sqrt(log(2))*erfinv(0.999999);
    c_i=sigma*sqrt(2/N_i)*ones(size(n));
elseif strcmp(Method_type,'MCM')==1
    n=rand(N_i,1);
    f_i=fmax*sin(pi*n/2);
    c_i=sigma*sqrt(2/N_i)*ones(size(n));
elseif strcmp(Method_type,'MSEM')==1
    n=(1:N_i)';
    f_i=kc*fc/(2*N_i)*(2*n-1);
    T=N_i/(2*kc*fc);
    M=1e3;
    t=linspace(0,T,M);
    f1=exp(-(pi*fc*t).^2/log(2));
    c_i=zeros(size(f_i));
    for k=1:length(f_i)
        c_i(k)=2*sigma*sqrt(trapz(t,f1.*cos(2*pi*f_i(k)*t))/T);
    end
elseif strcmp(Method_type,'MEDS')==1
    n=(1:N_i)';
    f_i=fc/sqrt(log(2))*erfinv((2*n-1)/(2*N_i));
    c_i=sigma*sqrt(2/N_i)*ones(size(n));
else
    error('MEthod is unknown')
end
if strcmp(phase,'rand')==1
    theta_i=rand(N_i,1)*2*pi;
elseif strcmp(phase,'permuted')==1
    n=(1:N_i)';
    U=rand(size(n));
    [x,k]=sort(U);
    theta_i=2*pi*n(k)/(N_i+1);
end