matlab-(含教程)通过眼图分析BPSK和4-PAM数字通信系统的鲁棒性

clc; clear; close all; warning off; addpath(genpath(pwd)); %Generating random BPSK symbols N = 1000; %Length of the bit stream Tb = 0.01; %Time of a bit duration Rb = 1/Tb; %Bit rate fs = 100; %sampling frequency t_1 = 0:Tb/fs:N*Tb-Tb/fs; %time array t_2 = 0:2*Tb/fs:N*Tb-2*Tb/fs; t_sampled_1 = t_1(1:fs:(length(t_1) - 1)); %sampled t array with sampling frequency t_sampled_2 = t_1(1:2*fs:(length(t_1) - 1)); bit_stream = rand(1,N)>0.5; %Random binary bit stream BPSK_symbols = 2*(bit_stream)-1; %BPSK symbol stream BPSKUpsampled = [BPSK_symbols;zeros(Rb-1,length(BPSK_symbols))]; BPSK_Up = BPSKUpsampled(:).'; %sampling BPSK symbols %Plotting bit stream and BPSK symbol train figure; subplot(2,1,1) stairs(t_sampled_1,bit_stream); xlabel('Time (s)') ylabel('Amplitude') title('Transmit bit stream') xlim([0 0.5]) ylim([-0.2 1.2]) subplot(2,1,2) stem(t_sampled_1,BPSK_symbols,'filled'); xlabel('Time (s)') ylabel('Amplitude') title('BPSK symbol stream') xlim([0 0.5]) ylim([-1.2 1.2]) %Generating transmit signal with sinc pulse and without AWGN [Tx_signal1,BER1] = sinc_modulator_new(N,Tb,Rb,bit_stream,BPSK_Up,0); %Plotting transmitted impulse train figure; plot(t_1,Tx_signal1); hold on; stem(t_sampled_1,BPSK_symbols,'k','Linestyle','--'); xlabel('Time (s)') ylabel('Amplitude') title('transmitted impulse train') xlim([0 0.1]) %Generating eye diagram for transmit signal eyediagram(Tx_signal1,200,2*Tb) xlabel('Time (s)') title('Eye diagram for sinc function without AWGN') %% %Generating transmit signal with raised cosine pulse and without AWGN %(roll-off = 0.5) alpha = 0.5; %roll-off factor [Tx_signal2,BER2] = rcos_modulator_new(N,Tb,Rb,bit_stream,BPSK_Up,alpha,0); %Plotting transmitted impulse train figure; plot(t_1,Tx_signal2); hold on; stem(t_sampled_1,BPSK_symbols,'k','Linestyle','--'); xlabel('Time (s)') ylabel('Amplitude') title('transmitted impulse train') xlim([0 0.1]) %Generating eye diagram for transmit signal eyediagram(Tx_signal2,200,2*Tb) xlabel('Time (s)') title('Eye diagram for raised cosine function with roll off 0.5 and without AWGN') %% %Generating transmit signal with raised cosine pulse and without AWGN %(roll-off = 0.5) alpha = 1; %roll-off factor [Tx_signal3,BER3] = rcos_modulator_new(N,Tb,Rb,bit_stream,BPSK_Up,alpha,0); %Plotting transmitted impulse train figure; plot(t_1,Tx_signal3); hold on; stem(t_sampled_1,BPSK_symbols,'k','Linestyle','--'); xlabel('Time (s)') ylabel('Amplitude') title('transmitted impulse train') xlim([0 0.1]) %Generating eye diagram for transmit signal eyediagram(Tx_signal3,200,2*Tb) xlabel('Time (s)') title('Eye diagram for raised cosine function with roll off 1 and without AWGN') %% % Task 2 %Generating AWGN Eb = 1; %average bit energy SNR = 10; %SNR in dB N_0 = Eb*10^(-0.1*SNR); %Noise power spectral density AWGN = ((N_0/2)^0.5)*randn(1,N*fs); %Generating transmit signal with sinc pulse and without AWGN [Tx_signal4,BER4] = sinc_modulator_new(N,Tb,Rb,bit_stream,BPSK_Up,AWGN); %Plotting transmitted impulse train figure; plot(t_1,Tx_signal4); hold on; stem(t_sampled_1,BPSK_symbols,'k','Linestyle','--'); xlabel('Time (s)') ylabel('Amplitude') title('transmitted impulse train') xlim([0 0.1]) %Generating eye diagram for transmit signal eyediagram(Tx_signal4,200,2*Tb) xlabel('Time (s)') title('Eye diagram for sinc function with AWGN') %% %Generating transmit signal with raised cosine pulse and with AWGN %(roll-off = 0.5) alpha = 0.5; %roll-off factor [Tx_signal5,BER5] = rcos_modulator_new(N,Tb,Rb,bit_stream,BPSK_Up,alpha,AWGN); %Plotting transmitted impulse train figure; plot(t_1,Tx_signal5); hold on; stem(t_sampled_1,BPSK_symbols,'k','Linestyle','--'); xlabel('Time (s)') ylabel('Amplitude') title('transmitted impulse train') xlim([0 0.1]) %Generating eye diagram for transmit signal eyediagram(Tx_signal5,200,2*Tb) xlabel('Time (s)') title('Eye diagram for raised cosine function with roll off 0.5 and with AWGN') %% %Generating transmit signal with raised cosine pulse and with AWGN %(roll-off = 1) alpha = 1; %roll-off factor [Tx_signal6,BER6] = rcos_modulator_new(N,Tb,Rb,bit_stream,BPSK_Up,alpha,AWGN); %Plotting transmitted impulse train figure; plot(t_1,Tx_signal6); hold on; stem(t_sampled_1,BPSK_symbols,'k','Linestyle','--'); xlabel('Time (s)') ylabel('Amplitude') title('transmitted impulse train') xlim([0 0.1]) %Generating eye diagram for transmit signal eyediagram(Tx_signal6,200,2*Tb) xlabel('Time (s)') title('Eye diagram for raised cosine function with roll off 1 and with AWGN') %% %Task 3 %Generating 4-PAM symbols PAM_symbols = zeros(1,N/2); for i = 1:2:N if bit_stream(i) == 0 && bit_stream(i+1) == 0 PAM_symbols(round(i+1)/2) = -1.5; elseif bit_stream(i) == 0 && bit_stream(i+1) == 1 PAM_symbols(round(i+1)/2) = -0.5; elseif bit_stream(i) == 1 && bit_stream(i+1) == 1 PAM_symbols(round(i+1)/2) = 0.5; elseif bit_stream(i) == 1 && bit_stream(i+1) == 0 PAM_symbols(round(i+1)/2) = 1.5; end end PAMUpsampled = [PAM_symbols;zeros(Rb-1,length(PAM_symbols))]; PAM_Up = PAMUpsampled(:).'; %sampling PAM symbol stream %Plotting bit stream and 4-PAM symbol train figure; subplot(2,1,1) stairs(t_sampled_1,bit_stream); xlabel('Time (s)') ylabel('Amplitude') title('Transmit bit stream') xlim([0 0.5]) ylim([-0.2 1.2]) subplot(2,1,2) stem(t_sampled_2,PAM_symbols,'filled'); xlabel('Time (s)') ylabel('Amplitude') title('4-PAM symbol stream') xlim([0 0.5]) ylim([-1.7 1.7]) %Generating AWGN Eb = 1; %average bit energy SNR = 10; %SNR in dB N_0 = Eb*10^(-0.1*SNR); %Noise power spectral density AWGN_PAM = ((N_0/2)^0.5)*randn(1,(N/2)*fs); %Generating transmit signal with sinc pulse and with AWGN [Tx_signal7,BER7] = sinc_modulator_PAM(N/2,Tb,Rb,bit_stream,PAM_Up,AWGN_PAM); %Plotting transmitted impulse train figure; plot(t_2,Tx_signal7); hold on; stem(t_sampled_2,PAM_symbols,'k','Linestyle','--'); xlabel('Time (s)') ylabel('Amplitude') title('transmitted impulse train') xlim([0 0.2]) %Generating eye diagram for transmit signal eyediagram(Tx_signal7,200,2*Tb) xlabel('Time (s)') title('Eye diagram for 4-PAM system with sinc function') %% %Generating transmit signal with raised cosine pulse and with AWGN %(roll-off = 0.5) alpha = 0.5; %roll-off factor [Tx_signal8,BER8] = rcos_modulator_PAM(N/2,Tb,Rb,bit_stream,PAM_Up,alpha,AWGN_PAM); %Plotting transmitted impulse train figure; plot(t_2,Tx_signal8); hold on; stem(t_sampled_2,PAM_symbols,'k','Linestyle','--'); xlabel('Time (s)') ylabel('Amplitude') title('transmitted impulse train') xlim([0 0.2]) %Generating eye diagram for transmit signal eyediagram(Tx_signal8,200,2*Tb) xlabel('Time (s)') title('Eye diagram for raised cosine function with roll off 0.5 4-PAM system') %% %Generating transmit signal with raised cosine pulse and with AWGN %(roll-off = 1) alpha = 1; %roll-off factor [Tx_signal9,BER9] = rcos_modulator_PAM(N/2,Tb,Rb,bit_stream,PAM_Up,alpha,AWGN_PAM); %Plotting transmitted impulse train figure; plot(t_2,Tx_signal9); hold on; stem(t_sampled_2,PAM_symbols,'k','Linestyle','--'); xlabel('Time (s)') ylabel('Amplitude') title('transmitted impulse train') xlim([0 0.2]) %Generating eye diagram for transmit signal eyediagram(Tx_signal9,200,2*Tb) xlabel('Time (s)') title('Eye diagram for raised cosine function with roll off 1 4-PAM system')