FPGA-based OFDM Baseband Communication System Design And Implementation

IEEE 802.11a is one of the standards in IEEE originally determined wireless LAN, which is mainly used to connect the office LAN and campus network users to the user terminal through wireless access, providing potential ways for telecommunication mobility, personality, and multimedia applications. And it becomes one of the effective broadband wireless accesses. IEEE 802.11a physical layer convergence protocol applies Orthogonal Frequency Division Multiplexing ( OFDM) modulation technology standards. OFDM is a multi-carrier modulation technique which transfers high-speed low-speed data stream into many sub-data stream, using multiple orthogonal subcarriers and overlapping simultaneous transmission. Compared with traditional non-overlapping multi-carrier technology, the use of overlapping multi-carrier OFDM technology can save nearly 50% of the bandwidth. OFDM technology has high spectrum efficiency and strong anti-interference ability and other advantages, so it is highlighted among the new generation of communications technology.The thesis is based on the deep understanding of OFDM technology, meanwhile, it also combines Xilinx Corporation's ISE development tools to establish model for the system, and then according to IEEE 802.11a physical layer standard, a base-band OFDM communication system of FPGA implementations is recommended. The whole design is based on the current mainstream top-down design method, which is from the overall design to detailed design and then gradually refines.In the process of implementing the FPGA systematic modules, the thesis is designed for a 50-million gates Xilinx Spartan-3E-XC3S500E chip, in accordance with IEEE 802.11a frame format, based on the OFDM communication system with the detailed design of each module and simulation. In the part of OFDM baseband communication system design, the thesis is divided into the interleaver module, 16QAM modulation module, IFFT, deinterleaving module and 16QAM demodulation module. Under ISE development environment, the Verilog description language realizes features of each module, while using the ISE simulation tools build the function simulation of each module.In general, the thesis firstly introduces the development of wireless mobile communications and wireless local area network aiming at an overview of OFDM technology development and application status, and secondly it starts from the principle of OFDM, describing OFDM system architecture description and focusing the latest research, and finally based on IEEE 802.11a protocol, it implements OFDM baseband communication system according to FPGA.With the popularity of OFDM technology and the future of the OFDM communications technology, the thesis is therefore believed to have a certain reference value.