Signal recovery in Frequency domain?
You need to consider the FFT output as containing the received data modulated onto 128 (FFT size) different carrier frequencies. Those 128 signals are then demodulated separately to yield 128 symbols. Each symbol can contain 2-bits for example, if QPSK modulation is considered. See the diagram below from Wikipedia:



To understand this a bit better take a look at the Transmission System:

Notice that the serial input signal is parallelised, encoded and applied to different bins in the IFFT. This effectively "modulates" the encoded data onto different carriers corresponding to the IFFT bin frequencies. Finally this signal may be modulated onto a radio carrier.