8. An FSK modulator sends one of the following signals S1 (t)=Acos(@t),iTt<(i+1)T (Q5.3) (Q5.4) (Q5.5) Getting It from Here to There: Modulators and Demodulators (Q5.6) where (Q5.7) (a) Find an orthonormal basis for these four signals; (b) Build an optimal demodulator when the FSK signal is received in the presence of AWGN. 9. Consider a binary FSK modulator which transmits one of the following signals: so(1)=Acos(a)t+0) (Q5.8) (Q5.9) where 00,A1 = uniform random value in [0,2]] (Q5.10) (a) Find an equation relating W0 and W1 such that the two transmitted signals are orthogonal, i.e., such that (i+1)T (Q5.11) For the remainder of this problem, assume that the two transmitted signals are orthogonal. (b) Find an or thonormal basis for the two transmitted signals. (c) Plot the two transmitted signals on the orthonormal basis. (d) Assume that the signals out of a binary FSK modulator are equally likely, and that they are sent over an AWGN channel. Draw a block diagram of the optimal demodulator. (e) Express, on the plot you drew in (c), the operation of the decision device in the demodulator. 10. Evaluate the probability of error when a modulator sends one of two equally likely symbols; the modulator outputs are either 0 or 1, as shown in Figure Q5.3; the channel adds AWGN an optimal demodulator is used. Chapter Five Q1(t) so= O Figure Q5.3 Modulator outputs on orthonormal basis 11. Determine the output symbol rate of the 8-PSK modulator given An analog input enters a sampler - the analog input has a maximum frequency of 12 kHz. The signal is sampled at the Nyquist rate. The sampled signal enters into an 8-level quantizer. The quantizer output passes through a symbol-to-bit mapper. The bits from the mapper enter into the 8-PSK modulator. Chapter Channel Coding and Decoding: Part 1-Block Coding and Decoding e're now near the midpoint of the book. This chapter is all about what's known as channel coding, and its partner, channel decoding. We'll start with a brief overview of the meaning of the words channel coding and 