Dear Friends,
first I had the following constraint:
log( real ( eye(3,3) + h*X*h' ) ) >= u1
where h is a 1 by 3 vector, X is a 3 by 3 hermitian matrix. To change the form of the problem, I replaced X by ww^H where w is 3 by 1 vector. Then, I used anti-log to reach the following constraint as:
abs(h*w2)>=sqrt(2^u1 - 1);
but I get the following error:
Disciplined convex programming error:
Illegal operation: sqrt( {convex} ).
Then, I tried to change to
norm([h*w , 1])>=sqrt(2^u1);
However, I got the same error as:
Disciplined convex programming error:
Illegal operation: sqrt( {convex} ).
I tried to remove the \sqrt() by reforming it as:
(norm([H_A.'*w2 , 1]))^2>=(2^u1);
But I got another error as:
Disciplined convex programming error:
Illegal operation: {convex} .^ {2}
Then I tried:
norm([H_A.'*w2 , 2])>=(2^u1);
There was another error like:
Disciplined convex programming error:
Invalid constraint: {convex} >= {log-affine}
finally, I could not get a format that falls within the rule set of CVX. Is there any way to solve this issue?
Most importantly, does my approach reduce from the difficulty of the problem? (changing the constraint by taking anti-log) It seems that still the constraint is from the log family and the complexity may remain the same. However, the problem will not be SDP anymore.