OFDM Phase compensation
It's not completely clear from your question, but I interpret your situation as:


You have a set of OFDM symbols that have been passed through a multipath channel.
You have generated an equalization matrix of phase shifts (in radians) that you want to apply to each subcarrier of each symbol.
You're not sure how to apply the phase shifts to the OFDM symbols.


Being able to implement an equalizer via simple multiplication is one of the benefits of OFDM, since one can assume that fading is flat across each subcarrier's channel. To apply a phase shift of $\theta$ radians to a complex number $x = a + jb$, do the following multiplication:

$$
\tilde x = e^{j\theta}x
$$

$$
\begin{align*}
\tilde x &amp;= \left(\cos(\theta) + j \sin(\theta)\right) \left (a + jb\right) \\
&amp;= \left(a \cos(\theta) - b \sin(\theta)\right) + j \left(a \sin(\theta) + b \cos(\theta) \right)
\end{align*}
$$