```
clc,clear;
close all;
N = 3;
b = rand(N,1) +1i*rand(N,1);
b1 = kron(b,b);
cvx_begin
variable phi(N-1,1) complex
psi = [1;phi];
minimize (norm(kron(psi,psi)-b1))
subject to
norm(phi) <= 1;
cvx_end
```

`kron(matrix variable, matrix variable)`

is non-convex, and is not allowed by CVX.

CVXUsers’ Guide Built-in functions Linear

For example, kron(X,Y) is valid only if either X or Y is constant

And `norm`

can only accept affine argument.

Please re-read

ok, i got it. thank you very much.