OFDM 系統加AWGN的性能模擬,訊號的Mapper使用QPSK,Guard interval 取資料的符元是1/4，輸出信號與原始信號比較出錯誤率。-Plus AWGN performance of OFDM system simulation, signal Mapper use of QPSK, Guard interval operators access to information, the yuan is 1/4, the output signal and compare th