How to realize the abs(phi)==1 constant?

Nonconvex
1

cvx_precision best
cvx_begin sdp quiet
variable phi(1,L) complex
expression x_k(Mt,L)
expression X2
variable t
minimize t

for k=1:Mt
X1(k,:)=X(k,:).*phi;
end

for m=1:Mt
X2(m)=quad_form(X1(m,:).’,R1);
end

max(X2)<=0.12*t;
sum(X2)<=t;
0.9<= norm(phi,‘fro’) <=1.1;

cvx_end

2

I know the constrait is non-convex.how to recast it into convex?

the message is

Disciplined convex programming error:
Invalid constraint: {real constant} <= {convex}

0.9<= norm(phi,‘fro’) <=1.1;

3

In general it is impossible to make a nonconvex set convex. In rare cases a convex relaxation might work. So cvx might be the wrong tool for you.

4

@Sasa You need to re-read the answers and link provided in reply to your previous question How to use >= constraint？ .

5

Thanks a lot. @Erling
Erling D.Andersen
@Mark_L_Stone