Intersymbol Interference - Countering ISI

Countering ISI

There are several techniques in telecommunication and data storage that try to work around the problem of intersymbol interference.

• Design systems such that the impulse response is short enough that very little energy from one symbol smears into the next symbol.

• Separate symbols in time with guard periods.
• Apply an equalizer at the receiver, that, broadly speaking, attempts to undo the effect of the channel by applying an inverse filter.
• Apply a sequence detector at the receiver, that attempts to estimate the sequence of transmitted symbols using the Viterbi algorithm.