In OFDM, the majority of Equalizers are used in frequency domain. I mean the signal is transmitted in time domain (after performing iFFT), then to estimate the channel we should perform FFt to use any type of equalization such that LS or MMSE.
My question, what's about if we perform the equalization in time domain? it means at receiver side, we perform any type of estimation/equalization before performing fft (estimate and equalize in time domain)? What's the advantages of using frequency domain OR using time domain estimation and equalization?