Friday, July 29, 2011

ISI in Channel

Causes for Intersynbol Interference
1. Multipath propagation
2. Inherent non-linear Frequency response of the channel

When the channel bandwidth is smaller than the signal bandwidth, the channel is bandlimited. Severe bandwidth Limitation causes intersymbol interference.
Also transmitting a signal at high modulation rate through a bandlimited channel can create intersymbol interference. As the modulation Rate increases the signals bandwidth increases. When the signals bandwidth becomes larger than the channel bandwidth, the channel starts to introduce distortion to the signal. This distortion is usually seen as intersymbol interference.