Book excerpt: This newly revised and expanded edition of an Artech House classic builds on its success as far and away the most comprehensive guide to digital modulation techniques used in communications today. The second edition adds a wealth of up-to-date, critical material, including: Five new chapters devoted to orthogonal frequency division multiplexing (OFDM) covering its basics and practical implementation issues: peak-to-average power ratio (PAPR) reduction, synchronization, fading channel performance, and mitigation methods, as well as the newest developments such as wavelet OFDM schemes; New modulations for optical communications; Enhanced coverage of M-ary amplitude shift keying (ASK); More accurate bit error rate (BER) equations for quaternary phase shift keying (QPSK) and quadrature amplitude modulation (QAM); Enhanced coverage of fading channel mitigation methods such as channel estimate and diversity techniques; Fast-access comparison of all modulation schemes; New appendixes covering trigonometry identities, Fourier transform pairs and properties, and Q-function and error function values.