Equalization

After the insertion of the CP, the signal is ready to be sent over the wireless channel. This is done through a process known as upconversion in which the modulated signal is mixed with a sinusoid of a particular frequency intended for the signal.

Role of channel estimates

We have learned that a linear convolution occurs between the transmitted signal $x[n]$ (that has a cyclic prefix attached) and the wireless channel $h[n]$.

$$y[n]=x[n]\ast h[n]=\sum_{m=0}^{N-1}x[m]h[n-m]$$ ...