Question

1. a. For music file of suitable format(.mp3,.dat etc.) add a random noise so that the SNR is 10dB with a Matlab program b. Remove the noise by a low pass filter of order 5 and a cutoff frequency of 4.5 KHz (Assume sampling frequency-44.1 KHz). And calculate the output SNR. Demonstrate the effectiveness by playing various music files Realize the filter and compare the results obtained using TMS 6713 processor c. d. Critically analyze the results obtained in terms of the SNR at the output.

Answer 1

a) load handel.mat;

Y=y(round(2/3*end:end));

SNR=10; % dB

Z=awgn(Y,SNR,'measured');
figure, plot(Z), hold, plot(Y,'r'), legend('AWGN snr=10dB',' Clean Signal')

b) Sampling Frequency fs = 44.1 KHZ

n=5

Cut off Frequency fc = 4.5 KHz

bit rate = nfs= 5*44.1k=220.5 KBPS

SNR = (1.76+6.02 n)DB

SNR = 1.76 + 6.02*5 = 31.86 DB.