How to express tau*W*log2(1+(theta*h)/(tau*sigma))==S in CVX?

Hello, I failed to express the following constraint:
-W*(rel_entr(tau, tau+thetah/sigma)/log(2)) - S == 0
where tau and theta are variables. Please help me.
In fact, the true expression is as

tau*W*log2(1+(theta*h)/(tau*sigma)) >= S can be reformulated as
-W*rel_entr(tau,tau+theta*h/sigma)/log(2) >= S.

However, nonlinear equality constraints are non-convex.

Thank you! Happy new year! But, if i change “==S” into “>=S”, the final solution will not be obtained at “==S”. My model is really “==S”. What should i do?

You should carefully read the link I provided.

Is your model convex?

No, my model is not convex.

You should not be trying to use CVX. CVX is not a general purpose optimization framework. It is designed specifically for certain kinds of convex optimization problems, as well as certain mixed-integer convex models and geometric programs 232. If you do not already know that your problem fits into one of CVX’s supported problem classes, then CVX is not the correct tool to use.