For a complex signal x to be transmitted over a channel with complex impulse response h, x will be convolved with h. What will the mathematical operation done in the reveiver to cancel the effect of h? I am confused because I have a code in which x is multiplied with h in the transmitter, and in the receiver, the received signal is multiplied by conjucate h and divided by h squared.
Dear Moahmed
The channel impulse response H(F) multiplied by X(F) in the frequency domain, and h(t) will be convoluted with x(t) in time domain.
In order to compensate channel impairment, at receiver you may use an channel equalizer.
We call it equalizing. We estimate the channel and then kind of divide with estimate in frequency domain. You can have zero forcing equalizer as simplest design. The code you have is basically kind of same.
http://courses.washington.edu/ee417/handouts/handout2.pdf
Dear Moahmed,
in OFDM we use one-tap equalizer, assuming the channel can be approximated by a single complex factor over the frequency range that a subcarrier occupies (layout of your subcarrier-bandwidths such that the channel can be assumed frequency-nonselective). This equalization is done by the complex multiplication.
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