simulink ofdm synchronization
yes, you need to take the complex conjugate before correlating with the original signal.
Well, you might be thinking why should one take complex conjugate of a real signal. Think in this way: Your signal is real at the Tx end, this signal is multiplied by a complex phasor when it passes through a channel, this will result in reception of a complex signal at the receiver end.
Now, if you are not introducing a channel between your Tx and Rx you can safely ignore the complex conjugation operation.
hope this answers your Q