Multiply the two variables

The constructed problem is as follows, where C of constraint C6 is related to the variable b. How this expression b*bT should be entered into CVX? I tried one method, but I get an error.

I don’t understand what is going on with \alpha^{-1} and 1/K. But other than that, it looks like C7 and C8 are perhaps a relaxation of the formula for C, which therefore should never be entered into CVX. But as I wrote before, I don’t know what the deal is with \alpha^{-1} and 1/K.

You should carefully read the paper or book (which I have not seen) from which this is extracted, and understand what formulations and reformulations or relaxations the authors propose.

Also, pay attention to the advice in Why the solution of CVX does not satisfy the constraint . You should try to get all non-zero input data to be within a small number of orders of magnitude of one; otherwise, the solver might encounter numerical difficulties, or reach incorrect conclusions., given that it uses double precision arithmetic rather than exact (infinite precision) arithmetic.

Thank you very much for reply, alpha and K is the constant in the picture. I will carefully read the paper again.