TPS Decoding in DVB T/H

Hallo, everyone

I have just decoded the TPS in DVB-T/H before and after the channel
equaqlizer.
The result by me shows, TPS Decoding before the channel eqalizer is
more robust as after the Channel Equalizer even by TU-6 or AWGN
channel.
Can somebody tell me the reason?
My Channel Equalizer works fine for the data tone.
thanks a lot

jjyy