0195136047.pdf

694 COMMUNICATION SYSTEMS FM modulator PM modulator f(t) Message signal Integrator f(t) ≡ PM modulator FM modulator f(t) Differe ...

15.2 ANALOG COMMUNICATION SYSTEMS 695 the FM signal into an AM signal can be achieved by passing the FM signal through an LTI sy ...

696 COMMUNICATION SYSTEMS sFM(t) f(t) R D R D L 1 L 2 Re Message FM signal signal (a) (b) (c) (d) Amplitude response Linear regi ...

15.2 ANALOG COMMUNICATION SYSTEMS 697 Bandpass filter Discriminator VCO Low-pass Received filter FM signal Ouput signal × Figure ...

698 COMMUNICATION SYSTEMS whereWrmsis the rms bandwidth off(t). GivenW 1 / 2 π= 2 .12 kHz,Wf/ 2 π=15 kHz, and Wrms/ 2 π= 4 .25 k ...

15.2 ANALOG COMMUNICATION SYSTEMS 699 Preemphasis KHp(ω) Preemphasis KHp(ω) DSB modulator 2 38-kHz oscillator (a) (b) SCA FM mod ...

700 COMMUNICATION SYSTEMS concern, PM and particularly FM systems are least favorable. Only in terms of their high level of nois ...

15.2 ANALOG COMMUNICATION SYSTEMS 701 image response is suppressed by using the antenna and other RF-tuned circuits as a filter. ...

702 COMMUNICATION SYSTEMS f f f 0 (b) (c) (a) fIF Bc 0 fc = fLO − fIF BRF < 2 fIF 0 fLO 2 fIF fc f'c = fLO + fIF Bc BRF Figur ...

15.2 ANALOG COMMUNICATION SYSTEMS 703 RF amplifier Mixer Antenna IF amplifier fIF = 10.7 MHz Bandwidth 210 kHz Local oscillator ...

704 COMMUNICATION SYSTEMS 10 μs 53.5 μs 15.4 ms 1.27 ms (a) (b) t t Figure 15.2.24Voltage waveforms.(a)Applied to horizontal def ...

15.2 ANALOG COMMUNICATION SYSTEMS 705 Beginning of first field Beginning of second field 485 lines in picture End of second fiel ...

706 COMMUNICATION SYSTEMS LPF 0–4.2 MHz mY(t) fY(t) Matrix LPF Color camera 0–1.6 MHz 2.0–4.2 MHz mI(t) sI(t) fI(t) LPF BPF BPF ...

15.2 ANALOG COMMUNICATION SYSTEMS 707 6 MHz assigned channel band Video (visual) carrier Luminance signal 4.2 MHz Audio (FM) Chr ...

708 COMMUNICATION SYSTEMS RF amplifier Mixer BPF 2.0–4.2 MHz LPF LPF Trap VCO 4.2 MHz LPF Matrix Audio loud speaker Picturetube ...

15.2 ANALOG COMMUNICATION SYSTEMS 709 Cell with base station Telephone central office MTSO Figure 15.2.31Cellular telephone conc ...

710 COMMUNICATION SYSTEMS AMPS, D-AMPS, or PCS areas) has been developed. TheGSM(Global System for Messaging communications) is ...

15.3 DIGITAL COMMUNICATION SYSTEMS 711 originalf(t) could be exactly reconstructed at all times, with no error by the receiver. ...

712 COMMUNICATION SYSTEMS Output Output L − 1 ( 2 ) Midriser (a) (b) Midtread δv L − 1 ( 2 )δv ≈ ≈ ≈ ≈ ≈ ≈ ≈ ≈ L − 2 2 5 δv 2 3 ...

15.3 DIGITAL COMMUNICATION SYSTEMS 713 Quantization Error Sampling followed by quantization is equivalent to quantization follow ...