Equation Icon  ( − H12(k)R (k) − R(k)∗H12 (k)∗ H11 (k) − R(k)∗H22 (k)) H (k)Q0 (ik) + Q0 (ik)∗H (k) = ∗ . (3.66 ) H11(k ) − H22 (k)R (k ) H12(k) + H12 (k )