quiz3solns09

# quiz3solns09 - EE 230B Quiz 3 Solution Spring 2009 UCLA...

This preview shows pages 1–2. Sign up to view the full content.

EE 230B Quiz 3 Solution Spring 2009 UCLA Electrical Engineering Department Prof. G. Pottie Consider the following channel: z -1 2 -1/2 X X 2 -1/2 Σ To this is added AWGN with variance N 0 = 0.01. a) Determine and sketch the folded spectrum. Why would linear equalization be a poor choice for this channel? Form the autocorrelation function X(z): X ( z ) = 1 2 z 1 + 1 + 1 2 z 1 Then substitute for z: Xe j ω T () = 1 + 1 2 e j T + e j T = 1 + cos( T ) The cosine goes to -1 at half the period, that is, at an angular frequency of π. Thus, there is a null at the edge of the Nyquist interval, with the shape looking like a raised cosine filter. Linear equalization works poorly with in-band nulls in the folded spectrum. b) A DFE with two forward filter coefficients c 0 and c -1 will be used, along with a feedback filter with one coefficient c 1 . That is, K 1 = K 2 =1 Determine the minimum mse solution for the coefficient set. Following the formula, obtain 1/2 + N 0 1 + N 0 c 0 c 1 = 1/ 2

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 03/29/2011 for the course EECS 100 taught by Professor Dun during the Spring '11 term at CSU Channel Islands.

### Page1 / 2

quiz3solns09 - EE 230B Quiz 3 Solution Spring 2009 UCLA...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online