xii Contents 9.7 Comparison of Modulation Methods 525 9.8 Summary and Further Reading 532 Problems 533 10 DIGITAL TRANSMISSION THROUGH BANDLIMITED AWGN CHANNELS 543 10.1 Characterization of Bandlimited Channels and Signal Distortion 543 10.1.1 Intersymbol Interference in Signal Transmission,547 10.1.2 Digital Transmission through Bandlimited Bandpass Channels,549 10.2 The Power Spectrum of Digitally Modulated Signals 552 10.3 Signal Design for Bandlimited Channels 556 10.3.1 Design of Bandlimited Signals for Zero ISI-The Nyquist Criterion,558 10.3.2 Design of Bandlimited Signals with Controlled ISI-Partial-Response Signals,564 10.4 Detection of Partial-Response Signals 566 10.4.1 Symbol-by-Symbol Detection,567 10.4.2 Probability of Error for Symbol-by-Symbol Detection,570 10.4.3 Maximum-Likelihood Sequence Detection of Partial-Response Signals,573 10.4.4 Error Probability of the Maximum-Likelihood Sequence Detector,576 10.5 System Design in the Presence of Channel Distortion 577 10.5.1 Design of Transmitting and Receiving Filters for a Known Channel,578 10.5.2 Channel Egualization,582 10.6 Summary and Further Reading 599 Appendix 10A:Power Spectrum of Modulated Signals 601 10A.I The Power Spectrum of the Baseband Signal,601 10A.2 The Power Spectrum of the Carrier Modulated Signals,603 Problems 604 11 MULTICARRIER MODULATION AND OFDM 621 11.1 Orthogonal Frequency-Division Multiplexing 621 11.2 Modulation and Demodulation in an OFDM System 622 11.3 An OFDM System Implemented via the FFT Algorithm 626 11.4 Spectral Characteristics of OFDM Signals 629xii Contents 9.7 Comparison of Modulation Methods 525 9.8 Summary and Further Reading 532 Problems 533 10 DIGITAL TRANSMISSION THROUGH BANDLIM/TED A WGN CHANNELS 10.1 Characterization of Bandlimited Channels and Signal Distortion 543 10.1.1 lntersymbol lnteiference in Signal Transmission, 547 10.1.2 Digital Transmission through Bandlimited Bandpass Channels, 549 10.2 The Power Spectrum of Digitally Modulated Signals 552 10.3 Signal Design for Bandlimited Channels 556 10.3.l Design of Bandlimited Signals for Zero !SI-The Nyquist Criterion, 558 10.3.2 Design of Bandlimited Signals with Controlled !SI-Partial-Response Signals, 564 10.4 Detection of Partial-Response Signals 566 10.4.1 Symbol-by-Symbol Detection, 567 10.4.2 Probability of Error.for Symbol-by-Symbol Detection, 570 10.4.3 Maximum-Likelihood Sequence Detection of Partial-Response Signals, 573 10.4.4 Error Probability of the Maximum-Likelihood Sequence Detect01; 576 10.5 System Design in the Presence of Channel Distortion 577 10.5.1 Design of Transmitting and Receiving Filters. for a Known Channel, 578 10.5.2 Channel Equalization, 582 10.6 Summary and Further Reading 599 Appendix lOA: Power Spectrum of Modulated Signals 601 JOA.I The Power Spectrum of the Baseband Signal, 601 JOA.2 The Power Spectrum of the Carrier Modulated Signals, 603 Problems 604 11 MUL TICARRIER MODULATION AND OFDM 1 1.1 Orthogonal Frequency-Division Multiplexing 621 11.2 Modulation and Demodulation in an OFDM System 622 1 1.3 An OFDM System Implemented via the FFT Algorithm 626 11.4 Spectral Characteristics of OFDM Signals 629 543 621