Entropy and random feedback

Let C ∈ C m×n . The Frobenius norm of C is defined as $$ {\left\| C \right\|_F} = \sqrt {TrC{C^ * }} ,$$ where C* denotes the complex-conjugate transpose and Tr denotes trace. The spectral norm of C is defined as $$ \left\| C \right\| = \sqrt {{\lambda _{\max }}\left( {C{C^ * }} \right)} , $$ where λmax denotes the maximum eigenvalue.