High speed downlink packet access

One of the most significant additions to the W-CDMA specifications is the incorporation of high speed downlink packet access (HSDPA). Standardization of this new technology began in 2002 in W-CDMA Release 5. HSDPA increases downlink peak data rates and packet data efficiency, making the system more competitive with other high data rate wireless technologies in use today. This thesis tells the major changes that HSDPA introduces in the W-CDMA physical and transport layers, including new link adaptation techniques and modifications to the structure of the physical channels, modulation, and coding. In the first chapter; the importance and purpose of digital communication was explained. In the second chapter; I/Q modulation, polar diagrams, I/Q formats and the purpose of I/Q usage were described. In the third chapter; digital modulation types, bit rate and symbol rate were explaned and 16QAM modulation was modelled in MATLAB programming language. In the fourth chapter; UMTS system, UMTS services, UMTS architecture, 3G frequencies, basic UMTS codes, UMTS time divisions, channel coding and UTRA channels were analyzed in detailed. In the fifth chapter, HSDPA structure, HSDPA channels, HSDPA channel coding, maximum data rate, HARQ, usage of incremental redundancy, internal TTI and HARQ processes were analyzed. In the sixth chapter; MAC architecture was described. In the seventh chapter; HSDPA system capacity and performance were investigated with some examples. In the eight chapter; an HSDPA process was modelled and simulated in MATLAB. All configurations were tested and results were compared among each others. In the ninth chapter; the results of this simulation were analyzed with comments and advantages of a HSDPA system were explained.