WiMAX Algorithm Analysis And Its Platform Design

With the rapid advancement of social informatization, traditional access techniques have become the bottleneck in the development of the next generation broadband communication networks, and therefore broadband access is considered to be an inevitable trend. Among the numerous burgeoning access technologies, broadband wireless access has attracted the most attention from the communication industry during recent years, due to its particular advantages in system performance. As a broadband wireless access scheme for WMAN (Wireless Metropolitan Area Networks), WiMAX (World Interoperability for Microwave Access) has received primary concern because of its outstanding system performance and wide market outlook.The WiMAX system achieves wide bandwidth and large coverage, which makes the algorithms applied in it highly complex. Therefore, greater demands are made on the platform for the WiMAX system. Algorithms with high complexity can only be realized in powerful processors, and only the buses supporting large bandwidth and high speed can satisfy the request for large data throughput. At the same time, in order to meet the demands in different applying situations, multiple realization modes and optional configurations are included in the WiMAX standard, which requires the platforms to rapidly adapt themselves to the changes in algorithms.The increasing requirement in platform flexibility makes the hardware platform become softer and softer. Software radio, FPGA and other emerging technologies are applied. As a result, more and more traditional special hardware modules in the platforms are replaced by lines of codes, and more and more analog modules are converted into digital modules. In addition to the improvement in platform flexibility, system digitalization also makes the whole platform more stable and reliable. In digital system, the position of AD and DA is required to be as closer to the antenna as possible. However, in modern communication platforms, AD and DA can already be tagged along with the RF module due to the application of ultra high speed AD and DA modules, resulting from the rapid development of mixed-signal semiconductor technology.At the beginning of this thesis, the standardization process and application prospect of WiMAX will be introduced. Then the request for system platform which WiMAX needs support from will be given: wide bandwidth, high performance, portable, and flexible.A comprehensive understanding of the WiMAX technology is needed before westart to design the corresponding platform. Therefore, the structure design for the error correction module, which is the key module of 802.16e OFDMA physical layer downlink receiver, will be chewed over. The error correction module is one of the largest data throughput modules in the whole broad-band receiver, so a good structure design for this module can greatly lighten the pressure in physical platform designing. In addition, the entire simulation in 802.16e downlink will be expatiated in this thesis, in order to prove the rationality in module designing.Another emphasis of this thesis is the software and hardware design of the whole 802.16 baseband communication platform, which can be divided into four parts: the embedded system, DSP, FPGA and AD&DA. The embedded system, DSP, and FPGA can be built as three separate systems. However, as the constituting modules of the whole platform, they must work cooperatively. In this thesis, the difficulties in platform design lie in three aspects: the customization of the embedded operating system, port design between different modules, and the determination in software and hardware framework.At the end of this thesis, a platform-based FIR filter design will be discussed in detail, and the realization structure based on DSP and FPGA modules will be given. The entire design process of the FIR filter can embody the convenience in algorithm realization, which is resulted from the excellent framework of the whole platform.