+ Preemphasis LHS R signal L RHS signal Frequency doubler Pilot tone (a) + Preemphasis Composite baseband spectrum L+R Pilot tone L-R (DSB-SC) + FM modulator f (kHz) (b) 15 19 23 38 53 Lowpass filter Deemphasis + L Audio amplifier FM discriminator Narrowband filter Frequency doubler Bandpass R Audio ✗ Deemphasis + filter amplifier (c) and (c) FM stereo receiver. FIGURE A.25 FM stereo broadcasting: (a) FM stereo transmitter, (b) spectrum of FM stereo signal,

4-3) Similar to Lathi & Ding, Prob. P.4.2-3 For a DSB-SC signal g(t) = 2m(t)cos(4000) transmitting each of the following messages, (a) write an expression for G(f) and (b) sketch the magnitude spectrum |G(f)], specifying the FWHM (full width at half-maximum) of any spectrum peaks. a) m(t) = sinc²(100-50л) b) m(t)=400e-80,000r²

4-2) Lathi & Ding, similar to problem 3.8-5. For the filter shown below, with an input signal whose PSD is given by S⭑(f) = П(0.25лf): (a) Find the total input power; (b) Find the transfer function H(f); (c) Find the power spectral density (PSD) of the output signal; (d) Find the total output power of the signal 500 ΚΩ d 1 µF dt y(t)