69 Richard C. Dorf Broadcasting Zhen Wan University of California, davis 69.1 Modulation and Demodulation Jefferson F. Lindsey Ill Modulation· Superhet outhern Illinois University at Modulation. Frequency-Shift Keying. M-ary Phase-Shift Keying. Quadrature Amplitude Modulation Dennis e delitzsch 69.2 Rad Standard Broadcasting(Amplitude Modulation). Frequency Modulation Jerry Whitaker 69.3 Television Systen anning Lines and Fields. Interlaced Scannin Martin s. roden Fields. Synchronizing Video Signals. Television Industry Standards. Transmission Equipment. Television Reception California State University 69.4 High-Definition Television Stanley Salek Proposed Systems Hammett edison 69.5 Digital Audio Broadca The Need for dab·DA Design Almon H. Clegg Background Technical and Source Encoding. System Example: I 69.1 Modulation and demodulation Richard C. Dorf and Zhen Wan Modulation is the process of sing the source information onto a bandpass signal with a carrier frequenc fe This bandpass signal is called the modulated signal s(n), and the baseband source signal is called the nodulating signal m(t). The modulated signal could be represented by (r)=Relg(t)ejo] (69.1) s(t)=R(t)cos [o t+0(t) s(t)=x(t) cos o t-y(t)sin o t (69.3) where O.= 2Tf The complex envelope is g(t)=R(t)eje(n= x(r)+iy(r) (694) and g(t)is a function of the modulating signal m(t). That is, g(t)=gIm(t)] c 2000 by CRC Press LLC© 2000 by CRC Press LLC 69 Broadcasting 69.1 Modulation and Demodulation Modulation • Superheterodyne Technique • Pulse-Code Modulation • Frequency-Shift Keying • M-ary Phase-Shift Keying • Quadrature Amplitude Modulation 69.2 Radio Standard Broadcasting (Amplitude Modulation) • Frequency Modulation 69.3 Television Systems Scanning Lines and Fields • Interlaced Scanning Fields • Synchronizing Video Signals • Television Industry Standards • Transmission Equipment • Television Reception 69.4 High-Definition Television Proposed Systems 69.5 Digital Audio Broadcasting The Need for DAB • DAB System Design Goals • Historical Background • Technical Overview of DAB • Audio Compression and Source Encoding • System Example:Eureka-147/DAB 69.1 Modulation and Demodulation Richard C. Dorf and Zhen Wan Modulation is the process of impressing the source information onto a bandpass signal with a carrier frequency fc. This bandpass signal is called the modulated signal s(t), and the baseband source signal is called the modulating signal m(t). The modulated signal could be represented by s(t) = Re{g(t)ejwct} (69.1) or, equivalently, s(t) = R(t) cos [wct + q(t)] (69.2) and s(t) = x(t) cos wct – y(t) sin wct (69.3) where wc = 2pfc. The complex envelope is g(t) = R(t)ejq(t) = x(t) + jy(t) (69.4) and g(t) is a function of the modulating signal m(t). That is, g(t) = g[m(t)] Richard C. Dorf University of California, Davis Zhen Wan University of California, Davis Jefferson F. Lindsey III Southern Illinois University at Carbondale Dennis F. Doelitzsch 3-D Communications Jerry Whitaker Technical Press Martin S. Roden California State University Stanley Salek Hammett & Edison Almon H. Clegg CCi