| With the innovation of mobile terminal products, Users eager to be able to access the Internet while on the move to acquire the information and services they need at any time. 153.6Kbit/s is the highest data transfer rate could be provided by cdma2000 1x system. However, it is unable to meet the requirements of high-speed data services apparently. In this respect, EV-DO technology is released by 3GPP2 to support high-speed packet data service. It offers peak data rates of up to 2.4Mbit/s with 1.25 MHz bandwidth using Time-Division Multiplexing, higher order modulation, multi-user scheduling and other technologies.In this thesis, the capacitys of CDMA systems and EV-DO are calculated and compared, and a conclusion is drawn that system need overcome greater interference to provide High-speed data rate transmission with CDMA structure. Factors affecting the capacity are analyzed, and a phenomenon is found that the actual number of available code channel is much smaller than spreading factor(SF), which verify the previous conclusion from the side. Then, we can infer preliminarily that transmit using excessive parallel code channels may not be feasible.In this thesis, the chip rate of each channel for forward link in EV-DO system is verified. However, there are some conflicting descriptions on the implementation of rate among different literatures. Corresponding descriptions are compared and analyzed and a corrected block diagram is given.Wireless link budget is a complex process which involves a lot of parameters and complex formulas, but it is an essential step of network planning. Android is an open-source platform which provides us with a good solution. In this thesis, the parameters and formulas involved in the link budget are carded and an APP is designed for the link budget. |
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