Question

Please do Part 4 and Show all work!

1. 145 points) <FM/FSK Modulation/Demodulations A periodic wave m(t) in Figure 1 below The resulting FM signal is demodulated as shown in the following figure by using frequency discriminator. Assume no attenuation of the signal due to propagation loss (in other words assume amplifiers properly restored the amplitude of the transmitted signal at the receiver) [10 points] Find the Fourier Series (trigonometric Fourier Series) of the message signal m (t) where To = 4 sec. Forfullcreditvou havetoshowhowyouRottheansweras much details as possible [10 points] Calculate the 97% bandwidth of the signal m(t).97% bandwidth means the bandwidth which contains 97% power of the signal]. [5 points] Let's say we are doing FM modulation with m(t). In other words, m(t) frequency-modulates a carrier of frequency fe 1 MHz with the carrier amplitude of Ac 1. Calculate the bandwidth of the generated FM signal with K- 1000 Hz/V 1) 2) 3) 4) [10 points] Draw a block diagram implementing FM demodulator which demodulates the FM signal in part 3) using frequency discriminator technique. 5) [10 points] Let's consider m(t) as a PCM code, and it modulates (Frequency Shift Keying) a carrier of frequency fc 1 MHz with the carrier amplitude of A-1. Will the demodulator in Figure 2 demodulate the generated binary FSK (Frequency Shift Keying) signal justify your answer for full credit. Figure 1. The message signal m(t) with To-4 sec. Sample at time t LT, BPF tuned to Envelope detector S1 Choose 1 if s>S2 Choose oifSi<s2 Binary FSK wave Comparison device BPF tuned to la Envelope detector sample a S2 Sample at time ta kT, Figure 2. Demodulator in part 5) where Th-To/2.

Answer 1

68 사. scrim inahan ejuenc ;veわ Tune d Envelope 0正 EnveloRe deleces Toned fr, ere LAC

Hope you understand ...