FPGA Implementation of Key Components in OFDM Receiver

摘要

Orthogonal Frequency Division Multiplexing is the technique of choice in digital broad band applications. That must cope of highly dispersive transmission media at low receiver cost. It requires very accurate frequency synchronization between the receiver and the transmitter with frequency deviation of the subcarriers will no longer be orthogonal, causing inter-carrier interference (ICI). Therefore, OFDM has become one of most popular baseband modulation techniques of its high efficiency in combating multipath fading and its high data rate transmission capability for wireless communications. In baseband OFDM receiver consists of inner receiver and outer receiver. The inner receiver performs signal detection; carrier frequency offset (CFO) estimation, CFO compensation, symbol timing detection, cyclic prefix (CP) remove, FFT, channel estimation, channel equalization, phase tracking, phase compensation and QAM slicing. The outer receiver includes of deinterleaver, depuncturer, Viterbi decoder and descrambler. The function of OFDM outer receiver is necessary to decode the received signal and it adopts a number of area efficient hardware structures to reduce the hardware cost. The objective is to implement of OFDM baseband outer receiver in Xilinx vertex-4 Field Programmable Gate Array Logic (FPGA) and using Hardware Description Language (HDL).