Design And Implementation Of The MS API For OFDMA System

As the emerging of new mobile multiple services constantly, in order to use limited frequency resources to meet the demand for material culture, the traditional cellular mobile communication system will evolve to broadband.At the same time, the broadband wireless access technologies is developing quickly, it combines with many advanced technologies, such as OFDM technology.OFDM is a high transmission technology in the wireless propagation environment. It is fitted to transmit high-speed data in the wireless channel which has multi-path delay and Doppler frequency shift.It's effective against multi-path effects and frequency selective fading, eliminating the ISI, and with high channel utilization. OFDMA is a multi-user version of the popular OFDM modulation scheme for multi-user access.In this paper, we first introduce the theory of OFDM key technology, and also the strength and weakness of OFDM.Then we introduce the development environment and the development tools briefly. Then we will do a detail analyze of the data processing characters of MAC and PHY, function requirements of the interface module between the 2 layers, and describe the working scheme in detail.At the same time, we proposed the implementation architecture of API in mobile station on the DSP chip of PC205,and also the message flow through these modules.At last, after the requirement analyzes, we give the function describe for each module, and then a design and implementation proposal of each module in the MS API. The paper proposed a method by handling multi-port and multi-rate by maintenance of a multi-task polling state-machine, which can not only implement the function but also ensure the normal working of the MAC and PHY.