The Software Defined Radio Implementation For WiMAX System

Broad-band wireless accessing technology, one of the most promising accessing technologies in the next generation communication system, has being received more and more attention. WiMAX system, a emerging broad-band system designed for WMAN, can not only provide high speed wireless connection to the Internet, but also multimedia service at the telecommunication level as well as 10 times wider coverage than the 3G base-station.As an emerging technology, Software Defined radio has been widely used in modern communications system. It has the complete programmability, and can realize the function of wireless radio by software programming. At the same time it uses the modular structure so as to facilitate the replacement of hardware modules and the software upgrading. And it can provide various communication service through using different algorithms and real-time waveform configuration.However the software defined radio also needs hardware platform to realize the final function. Therefore, this article firstly introduces the multi-processor hardware platform for WiMAX system which is based on the ARM, DSP, FPGA processors as well as the function each processor performes. Then we mainly analyze the internal structure of TigerSHARC DSP in details which mainly undertakes the physical baseband processing. Because the function of each layer is performed on different processors, it's important to guarantee the correct data communication among them during the implementation of our system. So then we specially introduce the primitive interaction between MAC and PHY as well as the definition of each primitive. Furthermore, the realization of this interactive process is introduced in details on our special hardware platform too. Finally based on the interactive process, we design the software framework of the physical layer's transceiver for the WiMAX system in order to control the operation of whole system.In the following chapters, we emphatically introduce the optimization method for the implementation of the transmitter and the receiver of WiMAX system on DSP. Firstly, we analyze the protocol flow of WiMAX transmitter, and then analyze the realization method and the code optimization of some modules. As the agreement of 802.16, the WiMAX system must support many kinds of configuration parameters as well as its good extension, so we mainly use the modular design method and program by software during the system realization, in order to facilitate the system evolution later. As for WiMAX receiver, we mainly introduce the different adjusting algorithm aimed at erasing the different kinds of errors. The article not only gives the MATLAB simulation result of each algorithm, but also gives simplification algorithms as well as the optimized process onTigerSHARC DSP. These algorithms can satisfy the need of present system from the implementation result.Finally, in order to test the design of whole system, we specially built the test platform to test the whole system including the primitive interaction between MAC and PHY. Because the system is a multi-processor platform and the data communication occurs in different processors, we have to use different steps to test these complex processes. As the result shown, the whole system we designed can run stably on our mulit-processor platform.