9-2. Determine the maximum bit rate for an FSK signal with a mark frequency of 48 kHz, aspace frequency of 52 kHz, and an available bandwidth of 10 kHz.

3 kbps

9-4. Determine The maximum bit rate for an FSK signal with a mark frequency of 102 kHz, aspace frequency of 104 kHz, and an available bandwidth of 8 kHz.

3 kbps 9-6. For the QPSK modulator shown in Figure 9-17, change the + 90° phase-shift network to- 90° and sketch the new constellation diagram.

Q I Phase 0 0 +1350 1 +451 0 -1351 1 -45

9-8. For an 8-PSK modulator with an input data rate (fi) equel to 20 Mbps and a carrierfrequency of 100 Mhz, determine the minimum double-sided Nyquist bandwidth (fN) and thebaud. Sketch the output spectrum.

6.667 MHz, 6.667 Mbaud

9-10. For a 16-QAM modulator with an input bit rate (fb) equal to 20 Mbps and a carrierfrequency of 100 MHz, determine the minimum double-sided Nyquist bandwidth (fN) and thebaud.

5 MHz, 5 Mbaud

Sketch the output spectrum.

9-12. Determine the bandwidth efficiency for the following modulators, a. QPSK, fb = 10 Mbps 2 bps/Hzb. 8-PSK, fb = 21 Mbps 3 bps/Hzc. 16-PSK, fb = 20 Mbps 4 bps/Hz

9-14. For a QPSK system and the given parameters, determinea. Carrier power in dBm. b. Noise power in dBm. c. Noise power density in dBm. d. Energy per bit in dBJ. e. Carrier-to-noise power ratio. f. Eb/NO ratio.

C = 10-13 W fb = 30 kbpsN = 0.06 × I0-15 W B = 60kHz

a. C = - 100 dBmb. N = -132.2 dBmc. No = -180 dBmd. Eb = -174.77 dBJe. C/N = 32.23 dBf. Eb/No = 35.23 dB

9-16. Determine the minimum bandwidth and baud for a BPSK modulator with a carrierfreqency of 80 Mhz and an input bit rate Fb = 1Mbps. Sketch the output spectrum. B = 1 MHz, 1 Mbaud

9-18. For the QPSK demodulator shown in Figure 9-21, determine the I and Q bits for an inputsignal -sin ct + cos ct

I = 0, Q = 1

9-20. For an 8-PSK modulator shown in Figure 9-23, change the +90 phase-shift network to a-90 phase shifter and sketch the new constellation diagram.

Q I C Phase 0 0 0 +112.5 0 0 1 +157.5 0 1 0 +67.5 0 1 1 +22.5 1 0 0 -112.5 1 0 1 -157.5 1 1 0 -67.5

1 1 1 -22.5

9-22. For the 16-QAM modulator shown in Figure 9-33, change the 90° phase shift network to a- 90° phase shifter and determine the output expressions for the following I, I', Q, and Q' inputconditions: 0000, 1111, 1010, and 0101.

Q Q’ I I’ Phase 0 0 0 0 +1351 1 1 1 -451 0 1 0 -450 1 0 1 +135

9-24. For the DPSK modulator shown in Figure 9-40a, determine the output phase sequence forthe following input bit sequwnxw: 11001100101010 (assume the reference bit is a logic 1).