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Apr 13th, 2015 IZMIR UNIVERSITY OF ECONOMICS EEE 302 LABORATORY ASSIGNMENT III In this assignment, you can use the provided Matlab file, FM_simulation.m, to simulate narrowband and wideband Frequency Modulated (FM) waves and analyze their frequency spectrum. (1) Develop a Matlab code to simulate the modulation of a single-tone FM wave with 100 kHz carrier (of unit amplitude) and a modulating wave m(t ) sin( 2 1000t ) Plot the time-domain FM signals for modulation indices {0.1, 0.5, 1, 5, 10}. (2) Write a Matlab code to compute and plot the magnitude and phase of the spectrum (using fft() function) of the corresponding FM signals generated in part (1). (3) For a single-tone FM signal, the spectral lines are located at the frequencies, f c k1 f m1 , k1 0,1,2,... The power in the spectral line at fc+k1 fm1 is given by Pk1 , k 2 J k1 ( ) P 2 where P is the total power in the modulated carrier (at fc, corresponding to k1=0), and Jk(.) is a Bessel function of the first kind of order k. J k ( ) can be computed in Matlab as >> besselj(k,beta) The power in a specific harmonic relative to the power in the carrier can be computed as Pk1 P0 Compute P1 / P0 as a function of 20 log[ . J k1 ( ) J 0 ( ) ] (dBc ) (4) For each value, determine the power in the harmonics of the modulating frequency {fm1=1000 Hz) about the carrier {fc+k1 fm1 }. Compute how many side frequencies are required for 90% of the total power in each case?