Design and implementation of OFDM transmitter and receiver on FPGA hardware

Abstract

Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier modulation technique which divides the available spectrum into many carriers. OFDM uses the spectrum efficiently compared to FDMA by spacing the channels much closer together and making all carriers orthogonal to one another to prevent interference between the closely spaced carriers. The main advantage of OFDM is their robustness to channel fading in wireless environment. The objective of this project is to design and implement a base band OFDM transmitter and receiver on FPGA hardware. This project concentrates on developing Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT). The work also includes in designing a mapping module, serial to parallel and parallel to serial converter module. The design uses 8-point FFT and IFFT for the processing module which indicate that the processing block contain 8 inputs data. All modules are designed using VHDL programming language and implement using Apex 20KE board. The board is connected to computer through serial port and Nios development kit software is used to provide interface between user and the hardware. All processing is executed in Apex board and user only requires to give the inputs data to the hardware throughout Nios. Input and output data is displayed to computer and the results is compared using Matlab software. Software and tools which used in this project includes VHDLmg Design Entry, Synopsys FPGA Express, Altera Maxplus+II and Altera Quartus 3.0. Software tools are used to assist the design process and downloading process into FPGA board while Apex board is used to execute the designed module.