Simulation Of HSDPA Physical Layer And Study On Some Related Key Technologies

With the fast development of Information Industry, the high profit brought by the mobile wireless communication technologies and the limitation of wireless resources make the competition more serious. Many kinds of standards merge while new concepts and systems come out, and each one is being developed and improved to maintain certain strength within the field. In the year 2000, the High Speed Downlink Packet Access is brought forward by the 3rd Generation Partnership Project to improve the bandwidth efficiency, speedup the transmission rate and reach the available capacities. After several years' improvement, HSDPA becomes a competitive technology for the super 3rd Generation now, and attracts a lot of attention.All the research work here is based on the specifications related with HSDPA released by 3GPP. Through theoretical analysis and simulation, the algorithms and processes for HSDPA physical layer are systematically investigated, and some key technologies are also discussed. A relative integrated and feasible scheme is proposed in this thesis.First, the background of HSDPA is illustrated, and compared with 3GPP Release 99, the technology traits and the change it brings are discussed, such as the new transmit channel and physical channel, as well as the change of the frame. Meanwhile, the development of HSDPA is summerized, and the four key technologies such as AMC, HARQ, FCS å'Œ MIMO are briefly introduced.The key part of this thesis is the HSDPA modulation system with the flow chart of transmitter and receiver of the whole system. The related principles of HSDPA and basic modules are introduced. All these make the foundation for the further research of HSDPA. Two parts of the algorithms, Turbo and RAKE receiver, are emphasized. For the first one, Turbo encoding and decoding are discussed, and SOVA is implemented with detailed analyses;for the second one, traditional RAKE receiver is explained from three parts, such as the path searching, the data demodulation and the channel estimation, while a new RAKE with inter-path interference canceller is derived. Apart from this, the influence of wireless channel is discussed, Rayleigh fading channel is introduced from two aspects of time delay and Doppler shift and channel for HSDPA is modeled.For the enhancement technologies, MIMO is investigated. Simulating two kinds of technologies—one is based on Layered Space-Time Code to improve the bandwidth efficiency, and the other is based on STTD to supply transmit diversity—the influence brought by MIMO to HSDPA is testified. Finally, through the summarization of the whole work, some potential research directions are discussed.