Research And Implementation Of OFDM System With Its Related Theories

OFDM system is a very promising technology since it has many advantages, such as its high-efficient spectrum and ICI interference avoidance. It can also easily connect with MIMO and access technologies like FDMA, TDMA, and CDMA. Because different subcarriers can adopt different coding and modulation methods, the capacity of the channel is able to reach the optimum value.Firstly, the paper discusses characters of the wireless channel and simulates the Rayleigh fading channel feature using C language. Then the paper analyzes the mathematical model and the structure of OFDM system, and simulates the wave and spectrum of OFDM signal with MATLAB software. In the following chapters, the paper separately discuses the key technologies of OFDM system and simulates the algorithm which used to solve the problems. The key technologies are the synchronization, channel estimation, and PAPR problems. Finally, the paper designs the hardware structure of OFDM system.In the design of OFDM system part, the paper presents rules to choose the appropriate chips, and discusses the existed problems. The parameters and the frame of OFDM system are designed according to application system requirements. After considering the sender and receiver parts, the paper gives the key algorithms of the hardware design.The paper discusses OFDM system in detail, and introduces problems that may be encountered when implementing the system.