function y=mymsk(a,T,w,t)
%a=[0,1,0,1,1];
%T=0.05;
%w=2*pi*(5)/(4*T);
N=length(a);
d=zeros(1,N);
d(1)=a(1);
for k=2:N
    d(k)=xor(a(k),d(k-1));
end
I=zeros(1,N);
I(1)=0;
for k=2:N
    if mod(k,2)==0
     I(k)=d(k);
    else
     I(k)=I(k-1);
    end
end
ph=pi*I;
n=length(t);
for i=1:n
    temp=ceil(t(i)/T);
    if (temp>0)&(temp<=N)
        y(i)=cos((w-pi*(-1)^a(temp)/(2*T))*t(i)+ph(temp));
    else
        y(i)=0;
    end
end