MIMO_BPSK.rar_BER for MIMO-OFDM_MIMO BPSK_MIMO 瑞丽_MIMO-OFDM_ante

%KEY WORDS: MIMO BPSK frmLen = 100; % frame length numPackets = 1000; % number of packets EbNo = 0:2:20; % Eb/No varying to 20 dB N = 2; % maximum number of Tx antennas M = 2; % maximum number of Rx antennas % Seed states for repeatability seed = [98765 12345]; randn('state', seed(1)); rand('state', seed(2)); % Create BPSK mod-demod objects P = 2; % modulation order bpskmod = modem.pskmod('M', P, 'SymbolOrder', 'Gray'); bpskdemod = modem.pskdemod(bpskmod); % Pre-allocate variables for speed tx2 = zeros(frmLen, N); H = zeros(frmLen, N, M); r21 = zeros(frmLen, 1); r12 = zeros(frmLen, 2); z21 = zeros(frmLen, 1); z21_1 = zeros(frmLen/N, 1); z21_2 = z21_1; z12 = zeros(frmLen, M); error11 = zeros(1, numPackets); BER11 = zeros(1, length(EbNo)); error21 = error11; BER21 = BER11; error12 = error11; BER12 = BER11; % Set up a figure for visualizing BER results h = gcf; grid on; hold on; set(gca, 'yscale', 'log', 'xlim', [EbNo(1), EbNo(end)], 'ylim', [1e-5 1]); xlabel('Eb/No (dB)'); ylabel('BER'); set(h,'NumberTitle','off'); set(h, 'renderer', 'zbuffer'); set(h,'Name','Transmit vs. Receive Diversity'); title('Transmit vs. Receive Diversity' ); % Loop over several EbNo points for idx = 1:length(EbNo) % Loop over the number of packets for packetIdx = 1:numPackets data = randint(frmLen, 1, P); % data vector per user per channel tx = modulate(bpskmod, data); % BPSK modulation % Alamouti Space-Time Block Encoder, G2, full rate % G2 = [s1 s2; -s2* s1*] s1 = tx(1:N:end); s2 = tx(2:N:end); tx2(1:N:end, :) = [s1 s2]; tx2(2:N:end, :) = [-conj(s2) conj(s1)]; % Create the Rayleigh distributed channel response matrix % for two transmit and two receive antennas H(1:N:end, :, :) = (randn(frmLen/2, N, M) + ... j*randn(frmLen/2, N, M))/sqrt(2); % assume held constant for 2 symbol periods H(2:N:end, :, :) = H(1:N:end, :, :); % Received signals % for uncoded 1x1 system r11 = awgn(H(:, 1, 1).*tx, EbNo(idx)); % for G2-coded 2x1 system - with normalized Tx power, i.e., the % total transmitted power is assumed constant r21 = awgn(sum(H(:, :, 1).*tx2, 2)/sqrt(N), EbNo(idx)); % for Maximal-ratio combined 1x2 system for i = 1:M r12(:, i) = awgn(H(:, 1, i).*tx, EbNo(idx)); end % Front-end Combiners - assume channel response known at Rx % for G2-coded 2x1 system hidx = 1:N:length(H); z21_1 = r21(1:N:end).* conj(H(hidx, 1, 1)) + ... conj(r21(2:N:end)).* H(hidx, 2, 1); z21_2 = r21(1:N:end).* conj(H(hidx, 2, 1)) - ... conj(r21(2:N:end)).* H(hidx, 1, 1); z21(1:N:end) = z21_1; z21(2:N:end) = z21_2; % for Maximal-ratio combined 1x2 system for i = 1:M z12(:, i) = r12(:, i).* conj(H(:, 1, i)); end % ML Detector (minimum Euclidean distance) demod11 = demodulate(bpskdemod, r11.*conj(H(:, 1, 1))); demod21 = demodulate(bpskdemod, z21); demod12 = demodulate(bpskdemod, sum(z12, 2)); % Determine errors error11(packetIdx) = biterr(demod11, data); error21(packetIdx) = biterr(demod21, data); error12(packetIdx) = biterr(demod12, data); end % end of FOR loop for numPackets % Calculate BER for current idx % for uncoded 1x1 system BER11(idx) = sum(error11)/(numPackets*frmLen); % for G2 coded 2x1 system BER21(idx) = sum(error21)/(numPackets*frmLen); % for Maximal-ratio combined 1x2 system BER12(idx) = sum(error12)/(numPackets*frmLen); % Plot results semilogy(EbNo(1:idx), BER11(1:idx), 'r*', ... EbNo(1:idx), BER21(1:idx), 'go',... EbNo(1:idx), BER12(1:idx), 'bs'); legend('No Diversity (1Tx, 1Rx)', 'Alamouti (2Tx, 1Rx)',... 'Maximal-Ratio Combining (1Tx, 2Rx)' ); drawnow; end % end of for loop for EbNo % Perform curve fitting and replot the results fitBER11 = berfit(EbNo, BER11); fitBER21 = berfit(EbNo, BER21); fitBER12 = berfit(EbNo, BER12); semilogy(EbNo, fitBER11, 'r', EbNo, fitBER21, 'g', EbNo, fitBER12, 'b'); hold off;