16qam_星形和矩形星座圖調制解調matlab代碼

1、%%%軟件無線電課程設計%%方形、星形16QAM調制解調仿真%%%%%主程序clcclear%%定義參數(shù)fd=25010^6%碼元速率250Mfs=250010^6%濾波器采樣率fc=250010^6%載波頻率2.5Gf=1000010^6%對載波采樣data_len=200000%數(shù)據(jù)長度sym_len=data_len4%碼元序列長度M_QAM=16%QAM數(shù)k=log2(M_QAM)SNR=1:12%白噪聲信噪比%%bit_tx=

2、rint(1data_len)%產(chǎn)生隨機序列echooffrec_qam16=QamMod(bit_tx16)%方形16QAM調制star_qam16=SrarQamMod(bit_tx)%星形16QAM調制base_rec=base_shape(fdfsfrec_qam16)%基帶成型濾波base_star=base_shape(fdfsfstar_qam16)%基帶成型濾波fi=1:length(SNR)%信噪比從1dB到12dB計

3、算誤碼率SNR_=i%方形映射16QAMrf_rec_qam16=CarrierMod(fcfbase_rec)%載波調制rf_rec_qam16_n=awgn(rf_rec_qam16SNR(i)measured)%加噪聲[rec_qam16_rxbase_rec_rx]=CarrierDemod(fdfsfcfrf_rec_qam16_n)%載波解調bit_rec_rx=QamDemod(rec_qam16_rx16)%MQAM解調

4、[num_qam16perr_qam16_rec(i)]=biterr(bit_txbit_rec_rx)%誤碼率qam16_data_rec(i:)=rec_qam16_rx%scatterplot(rec_qam16_rx)%星形映射16QAMplot(timag(base_rec_rx(t)))title(方形映射I路)subplot(413)plot(treal(base_star_rx(t)))title(星形映射Q路)sub

5、plot(414)plot(timag(base_star_rx(t)))title(星形映射I路)%基帶眼圖N1=20000Tn=ffdeye_rex=base_rec(1:N1)eyediagram(eye_rexTn4Tn)title(方形基帶眼圖)eye_star=base_star(1:N1)eyediagram(eye_starTn4Tn)title(星形基帶眼圖)%%接收端星座圖%scatterplot(qam16_dat

6、a_rec(12:))figure(Name方形16QAM接收端星座圖)fi=3:3:12subplot(22i3)plot(real(qam16_data_rec(i:))imag(qam16_data_rec(i:)).)xmax=5axis([xmaxxmaxxmaxxmax])title([Snr=num2str(SNR(i))dB])endfigure(Name星形16QAM接收端星座圖)fi=3:3:12subplot(22

7、i3)plot(real(qam16_data_star(i:))imag(qam16_data_star(i:)).)xmax=3axis([xmaxxmaxxmaxxmax])gridontitle([Snr=num2str(SNR(i))dB])end%%功率譜密度f_plot%%誤碼率分析%16QAM誤碼率曲線figure(Name16QAM誤碼性能對比)%semilogy(SNRtheotheo_perr_qam16)%hol