test.asv

详细的OFDM设计过程

Q = 8;                              % Number of samples per symbol in baseband

pulse_shape = ones(1, Q);
% Matched filter impulse response. 
mf_pulse_shape = fliplr(pulse_shape);


m1 = [1+3i 4+i 4+3i 1-i 1+i 1-3i 1-3i 1+3i 4+i 4-i 4-3i];
    % Upsample the signal, apply pulse shaping.
    tx = upfirdn(m1, pulse_shape, Q, 1);

    %%%
    %%% AWGN Channel
    %%%
    
    % Compute variance of complex noise according to report.
    sigma_sqr = norm(pulse_shape)^2 / 10^(-3/10); ;

    % Create noise vector.
    n = sqrt(sigma_sqr/2)*(randn(size(tx))+j*randn(size(tx)));

    % Received signal.
    rx = tx + n;

    %%%
    %%% Receiver
    %%%
    
    % Matched filtering.
    mf=conv(mf_pulse_shape,rx);
    
    % Synchronization. The position and size of the search window
    % is here set arbitrarily. Note that you might need to change these
    % parameters. Use sensible values (hint: plot the correlation
    % function used for syncing)! 
    t_start=1
    t_end=t_start+50*8;
    t_samp = sync(mf, m1, Q, t_start, t_end)
    
    % Down sampling. t_samp is the first sample, the remaining samples are all
    % separated by a factor of Q. Only training+data samples are kept.
    r = mf(t_samp:Q:t_samp+Q*(nr_training_bits+nr_data_bits)/2-1);

    % Phase estimation and correction.
    phihat = phase_estimation(r, b_train);
    r = r * exp(-j*phihat);
        
    % Make decisions. Note that dhat will include training sequence bits