Answer Happy

(b) (17 points) You are asked to design a DSB-SC modulator to generate a modulated signal km(t) cos wet, where m(t) is a signal bandlimited to B Hz (See Figure 2). Figure 3 shows a DSB-SC modulator available. The bandpass filter is tuned to wc. The carrier generator available generates not cos wet but cos wet. M(0) A 1 -21B 0 21B Figure 2: Frequency spectrum of m(t) for Problem 3(b). m(t) km(t)cos! ਉਦਾ Bandpass Pilter cos ಹ್ಯ? (Carrier) Figure 3: DSB-SC modulator Problem 3(b). (i) (5 marks) Explain whether you would be able to generate the desired signal using only this modulator. If so, what is the value of k as shown in point c in Figure 3? (ii) (4 points) Determine the signal spectra at points b and c given in Figure 3, and indicate the frequency bands occupied by these spectra. (iii) (2 points) What is the minimum usable value of we? (iv) (4 points) Would this scheme work if the carrier generator output were cos? wet? Explain. (v) (2 points) Would this scheme work if the carrier generator output were cos” Wet for any integer n > 2?