求大神帮帮忙 为什么这个程序图像出不来

str = 'ph';
decimalvalue=real(str);
binaryvalue=dec2base(decimalvalue,2,8);
matrix1=size(binaryvalue);
a=matrix1(1,1);
b=matrix1(1,2);
bv=[];
for i=1:1:a;
for j=1:1:b;
bv1=binaryvalue(i,j);
bv1=bv1*1;
bv1=bv1-48;
bv=[bv bv1];
end
end
M=100;
N=length(bv);
bsignal=zeros(1,N*M);
bsignal(1:M:end)=bv;
p=ones(1,M);
s=conv(p,bsignal);
k1=length(s);
k1=k1-99;
signal=zeros(1,k1);
for i=1:1:k1;
signal(i)=s(i);
end
x=signal;
Ts=1/100;
plot(x,Ts);