I have a problem with using norm in CVX

I have a constraint given below.

                    for iUser=1:nUsers
                   otherusers = find(1:nUsers ~= iUser); 
                   interference = [1;diag(((reshape(channel(:,:,iUser,usercellindex(otherusers)),nTx,[])).')*(w(:,otherusers)))];

Here w are optimization variables that are complex.

When I run my CVX program, I get the following error

                  Error using cvx/pow_cvx (line 142)
                  Disciplined convex programming error:
                  Illegal operation: {convex} .^ {2}
                  (Consider POW_P, POW_POS, or POW_ABS instead.)

                  Error in  .^  (line 55)
                  z = pow_cvx( x, y, 'power' );

                  Error in  ^  (line 9)
                  z = power( x, y );

                  Error in Main (line 114)

The error message is telling you what you need to know. In this case, pow_pos is what you should use instead. But your problem violates other DCP rules anyway, so you’re not going to get much farther.