调用FPGA的IP核实现FFT运算，在xilinx的vertex4sx55FPGA的实现-Call FPGA implementation of the IP core FFT computation, in the Xilinx implementation of the vertex4sx55FPGA

vhdl ifft and fifo code with xilinx ip core to implement OFDM Basisband-vhdl ifft and fifo code with xilinx ip core to implement OFDM Basisband