On power-complementary FIR filters

Conditions are derived, under which two linear-phase FIR filter transfer functions H(z) and G(z) have the power-complementary property, i.e., |H(e^{j \omega})|^{2} + |G(e^{j\omega})|^{2} = 1 . It is shown that, the constraint of linear phase on the transfer functions strongly restricts the class of frequency responses that can be realized by a power-complementary pair.