Preface xv Acknowledgments xvii 1 Overview 1 1.1 History of Mobile Cellular Systems 1 1.1.1 First Generation 1 1.1.2 Second Generation 2 1.1.3 Generation 2.5 5 1.2 Overview of 3G 8 1.3 Proposals for 3G Standard 10 1.3.1 WCDMA 10 1.3.2 Advanced TDMA 11 1.3.3 Hybrid CDMA/TDMA 12 1.3.4 OFDM 12 1.3.5 IM