FPGA-based Orthogonal Frequency Division Multiplexing System Design And Implementation

Orthogonal frequency division multiplexing (OFDM, Orthogonal Frequency DivisionMultiplexing) technology is a multi-carrier digital modulation technique, which uses multipleorthogonal subcarriers to transmit information, with high spectral efficiency, and cost-effectivelycombat multipath low. Communication has been widely used. In recent years,it’s dedicated chipdemand urgently with the further application of OFDM. However, due to complexity of wirelesscommunications, changing the characteristics of OFDM systems to get the best performance ofwireless communication, access to high-performance ASIC is required to FPGA developmentplatform, the OFDM system, front-end functional design,Provide a basis for practicalapplications. This paper design an FPGA-based baseband OFDM system,with simulation andanalysis. Full completion of the transmitter and receiver design, involving analysis of OFDMsystem model, channel coding, QAM modulation, channel decoding, QAM modulation. And thesynchronization error for OFDM systems, channel fading, phase deviation sensitive paperproposed synchronization, channel equalization, phase tracking design. The main work thefollowing points:1、Based on the OFDM baseband system model simulation,study limiting and filtering,equalization, residual phase tracking to the transmission signals influence, to provide programguidance for the hardware design. According to the principle and mathematical model of OFDMand Matlab’s Simulink simulation software used to build the IEEE802.11a baseband OFDMsystem model simulation. Type were measured by limiting and filtering, equalization of theOFDM signal power spectral density of the remaining phase tracking the impact of thetransmission of data, and the corresponding simulation comparison to hardware design.2、More for wireless communications and interference by the characteristics of proposechange in statistical properties, convolution code algorithm, interleaving, cyclic prefix datatransmission scheme of protection, and accordingly the base of hardware implementation. At thereceiver, the correct reception of data separately proposed demodulation, deinterleaving,descrambling hardware implementation, in order to maintain the correct data recovery.andachieving the corresponding module OFDM hardware circuit design and simulation.3、The OFDM system for synchronization of key technologies based on short trainingsymbol proposed carrier synchronization and symbol synchronization based on training symbols design, it is effective on the time and frequency offset estimation and compensation effectivelyand improve the performance of the system.and achieving corresponding OFDM hardwarecircuit design and simulation.4、For wireless communication by wireless channel constraints and multi-path channel dueto inter-symbol interference caused by slow fading channel is proposed based on long trainingsymbol in frequency domain channel equalizer design, which effectively have received data forcalibration and recovery. and achieving the hardware circuit design and simulation.5、Based on the Matlab simulation to guide the remainder of the phase tracking residualphase tracking algorithm proposed hardware implementation, its deviation from the carriersynchronization data further phase adjustment.In this thesis, the algorithm based on a theoretical study, the IEEE802.11a standard,proposed OFDM system solutions based on FPGA hardware design, including overall programsettings, software simulation, hardware design, hardware simulation and verification, andthrough the Verilog HDL programming Xilinx IP Core provided by the company, ISE softwareplatform, Isim and Modelsim SE simulation tool to implement and verify. Finally, by usingdifferent algorithm to RTL optimization, simulation shows the feasibility of proposed programsand reliability. For the current OFDM dedicated circuit ASIC Design laid the foundation.