9.10 Consider the phase-coherent demodulator for M-ary FSK signals as shown in Figure 9.11. 1. Assume that the signal 28, uo(t) cos 2лfd, 0≤1≤T was transmitted; determine the output of the M-1 correlators at = T that corresponds to the signals um(t), m = 1, 2,..., M-1, when om om. 2. Show that the minimum frequency separation required for the signal orthogo- nality at the demodulator when mom is Af = 1.