A Practical Method for Correcting Phase Errors in a Transceiver System Comprising of OFDM + DUC and DDC
I don't think it would be reasonable to expect the phase to be exactly the same. The raised cosine filter for example has a linear phase response. Also don't forget that the auto-correlation for the cyclic prefix detection might find the frame starting at any of the 16 samples of the cyclic prefix, inducing an undetermined phase shift.

Do you have pilot sub-carriers? One simple way is to analyse their phase (which you know a-priori were transmitted with 0 (or some other known) phase) and rotate the sub-carriers in between the pilots (linearly interpolating between the phase of the pilots).