the test statistic. Therefore the optimum receiver can be realized
by the block diagram of Figure 10.7. This form of optimum demodulator realization lends
itself to the following interpretation. The matched filter, as usual, extracts the maximum
energy from the transmitted signal. However, because of the phase uncertainty, at the filter
output, only the envelope is looked at. For this reason the receiver is frequently known
as a noncoherent demodulator. Note also that the filter is a bandpass filter centered at the
carrier frequency fc.