Zero Forcing Equalizer

Zero Forcing Equalizer refers to a form of linear equalization algorithm used in communication systems which applies the inverse of the frequency response of the channel. This form of equalizer was first proposed by Robert Lucky. Zero Forcing Equalizer refers to a form of linear equalization algorithm used in communication systems which applies the inverse of the frequency response of the channel. This form of equalizer was first proposed by Robert Lucky. The Zero-Forcing Equalizer applies the inverse of the channel frequency response to the received signal, to restore the signal after the channel. It has many useful applications. For example, it is studied heavily for IEEE 802.11n (MIMO) where knowing the channel allows recovery of the two or more streams which will be received on top of each other on each antenna. The name Zero Forcing corresponds to bringing down the intersymbol interference (ISI) to zero in a noise free case. This will be useful when ISI is significant compared to noise. For a channel with frequency response F ( f ) {displaystyle F(f)} the zero forcing equalizer C ( f ) {displaystyle C(f)} is constructed by C ( f ) = 1 / F ( f ) {displaystyle C(f)=1/F(f)} . Thus the combination of channel and equalizer gives a flat frequency response and linear phase F ( f ) C ( f ) = 1 {displaystyle F(f)C(f)=1} .