Can OFDM modulate analog signal? I suppose that OFDM can't modulate analog signal. The basic mathematical description for OFDM is 
      $$ v(t)=\sum_{k=0}^{N-1}X_{k}\exp(j2\pi k t /T),\quad 0&lt;t&lt;T$$
In this equation, $X_k$ is a discrete value. 
So OFDM can not modulate an analog signal.
You are correct. However, the coefficients $X_k$ could be samples taken from an analog signal. These could be used in the receiver to recover the analog signal using interpolation.