 you to listen to your favorite radio station. It is my sincerest hope that this book provided you with a solid understanding of the basics of telecommunications systems engineering, without the mountain of "muck" created by intimidating attitudes and big words. Life is simple, if it's just explained that way. Chapter Twelve Problems 1. Figure Q12.1 shows the input to a modulator. Determine the output if (a) the modulator is an AM modulator. (b) the modulator is an FM modulator. (c) the modulator is a DSB-SC modulator. Figure Q12.1 Modulator input 2. Figure Q12.2 shows the input to a modulator. Determine the output (in the frequency domain) if (a) the modulator is an AM modulator. (b) the modulator is a DSB-SC modulator. Figure Q12.2 Modulator input -2.f fa fa 2.f a 3. Given that the signal x(t) in Figure Q12.3 is input to a DSB-SC modulator: (a) Determine the output of the modulator. (b) Assume this signal is sent over a channel which is ideal (the received signal equals the sent signal). Analog Communications (1) Determine the output of the demodulator when the demodulator is a perfect envelope detector. (2) Determine the output of the demodulator when the demodulator is a mixer, low-pass filter, and processing device as described in the chap- Figure Q12.3 DSB-SC input 4. Given the input in (Q12.1), provide an analytical equation for the modulator output when the modulator is ,O<t<< (Q12.1) , else (a) an AM modulator (b) a DSB-SC modulator (c) an FM modulator 5. An AM receiver is tuned to pick up the station at 600 MHz. Draw a block diagram of the AM receiver used to detect this signal. Annotated References and Bibliography While this book provides a streamlined overview of the world of telecommunica- tions engineering, I'd like to refer you to other books that can serve as useful resources. They offer some added detail on topics covered in this book, and address topics I didn't have the space to include in this book. Here's my recommended list, with some notes that I hope prove valuable. 1. B. Sklar, Digital C