Unformatted text preview: University of Illinois Spring 2011 ECE 361: Problem Set 8 Equalizers in BandLimited Communications Due: Thursday April 7 at 9:30 a.m. Reading: Lecture Notes: Lectures 1518 1. [Zeroforcing transversal filter] The discretetime model for a bandlimited channel has as channel response the sequence . 05 , . 2 , 1 . , . 3 , . 07 Design a twostage threetap equalizer for this channel. The symbol X [ m ] will appear in ˆ Y [ m ] (where it is the desired symbol) but not in the ISI affecting ˆ Y [ m + 1] and ˆ Y [ m 1] where it is forced to zero. However, X [ m ] might appear in the ISI affecting other symbols. What is the coefficient of X [ m ] in the ISI affecting ˆ Y [ m + 2] and ˆ Y [ m 2]? How does this compare with how much X [ m ] affects Y [ m + 2] and Y [ m 2]? Has zeroforcing helped or hurt these symbols farther away? 2. [Comparison of equalizers] The received signal in a communication system operating over a bandlimited channel is Y [ m ] = X [ m ] + 0 . 5 X [ m 1] +...
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 Spring '09
 Probability, Probability theory, conditional error probability

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