EE 200 – Fall 2009 (Weber) Homework 3 At the upper right corner on page 1 of all homeworks, show: Last name, First name Date EE 200, Homework # Show intermediate steps whenever possible. 1. For each of the following systems deﬁned below, indicate whether the sytem is linear, time invariant, both, or neither. You don’t have to show any proof of your answer, just indicate what type of system it is. a. y [ n ] = cos (2 πn ) x [ n ] e. y [ n ] = x [ n ] + 0 . 7 y [ n-1] b. y [ n ] = cos (2 πn/ 7) x [ n ] f. y [ n ] = x [ n ] + 0 . 3( x [ n-1]) 2 c. y [ n ] = cos (2 πn/ 7)( x [ n ] + x [ n-1]) g. y [ n ] = 5 x [ n ] + 2 d. y [ n ] = x [ n ] + 0 . 7 x [ n-1] h. y [ n ] = | x [ n ] | 2. A sampled signal is given by x [ n ] = 4 cos(0 . 3 πn-π/ 4) Find three continuous-time signals, x 1 ( t ), x 2 ( t ) and x 3 ( t ) of the form x ( t ) = A cos(2 πft + φ ) that when sampled at a sampling rate of f s = 1000 samples/sec. would each give this result. The frequencies of x 1 ( t ), x
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This note was uploaded on 02/26/2010 for the course EE 30446 at USC.