Rank: 90 based on 667 downloads (last 30 days) and 16 files submitted
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Hristo Zhivomirov

E-mail
Company/University
Techical University - Varna

Personal Profile:

Hristo Zhivomirov was born in Varna, Bulgaria, in 1987. He received his B.Sc. and M.Sc. degrees in Communication Engineering and Technologies from Technical University of Varna, Bulgaria in 2010 and 2012, respectively. He is currently an Assist. Professor in department of Theory of Electrical Engineering and Measurement and a Ph.D. student in department of Communication Engineering and Technologies, Technical University of Varna. Mr. Zhivomirov is a member of IEEE and FSEU. His research interests include the field of signal processing, circuits and systems, as well as audio and low-voltage measurements.

Professional Interests:
Signal Processing, Circuits and Systems

 

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Files Posted by Hristo View all
Updated   File Tags Downloads
(last 30 days)
Comments Rating
05 Jun 2014 Screenshot A-weighting filter with Matlab Implementation A-weighting of a signal via spectral processing in the frequency domain. Author: Hristo Zhivomirov signal processing 21 0
02 Jun 2014 Screenshot Interpolation of a signal with Matlab Implementation Interpolation in the time domain via zero-padding in the frequency domain. Author: Hristo Zhivomirov signal processing 17 0
14 Apr 2014 Screenshot Measurement of Loudspeaker Frequency Response with Matlab Implementation Frequency response measurement of a loudspeaker. Author: Hristo Zhivomirov audio, measurement 30 0
  • 5.0
5.0 | 1 rating
14 Apr 2014 Screenshot Measurement of Loudspeaker Radiation Pattern with Matlab Implementation Radiation pattern measurement of a loudspeaker. Author: Hristo Zhivomirov audio, measurement 23 0
  • 5.0
5.0 | 1 rating
14 Apr 2014 Screenshot Sound analysis with Matlab Implementation Time and frequency analysis, measurement of the crest factor, the dynamic range, etc. Author: Hristo Zhivomirov signal processing, sound analisys, not a function 64 0
  • 5.0
5.0 | 3 ratings
Comments and Ratings by Hristo View all
Updated File Comments Rating
25 Feb 2014 Inverse Short-Time Fourier Transformation (ISTFT) with Matlab Implementation Time-Frequency resynthesis via Inverse Short-Time Fourier Transformation (ISTFT) Author: Hristo Zhivomirov

Hi Yousef,

First of all thank you for the comment and for your interest in my submission.
Now here is the answer:

1) choose h = wlen/(4*n), where n = 1, 2, 3, ... (h = wlen/2 does not meet OLA-constraint, check with WindowChoice.m).
2) choose nfft = wlen (nfft > wlen cause interpolation in the time domain of every signal segment = errors in resynthesis, so if you really want interpolation you must use zero-padding technique in time-frequency domain).

Try this:

clear, clc, close all

% define signal parameters
% sine-wave signal (stationary signal)

fs = 48000;
t = 0:1/fs:1-1/fs;
x = 10*sin(2*pi*t*10);

% define analysis and synthesis parameters
wlen = 64;
h = wlen/4;
nfft = wlen;

% perform analysis and resynthesis
[stft, f, t_stft] = stft(x, wlen, h, nfft, fs);
[x_istft, t_istft] = istft(stft, h, nfft, fs);

% plot the original signal
figure(1)
plot(t, x, 'b')
grid on
axis([0 1 -15 15])
set(gca, 'FontName', 'Times New Roman', 'FontSize', 14)
xlabel('Time, s')
ylabel('Amplitude, V')
title('Original and reconstructed signal')

% plot the resynthesized signal
hold on
plot(t_istft, x_istft, '-.r')
legend('Original signal', 'Reconstructed signal')

Best Regards,

Hristo Zhivomirov

30 Aug 2013 PSD (Power Spectral Density), and Amplitude Spectrum with adjusted FFT FFT computes PSD and one sided amplitude spectrum Y[f] of 1d signal Author: Youssef KHMOU

Figure 2 (Power Spectral Density, logarithmic scale) is not correct. The Y scale does not represent the PSD magnitude in dB. It is just the same PSD like Figure 1, but represented on logarithmic Y scale. If you want to have a PSD in dB, use PowerdB = 10*log10(Power) and plot(f, PowerdB).

Comments and Ratings on Hristo's Files View all
Updated File Comment by Comments Rating
10 Jun 2014 Sound analysis with Matlab Implementation Time and frequency analysis, measurement of the crest factor, the dynamic range, etc. Author: Hristo Zhivomirov Michael

10 Jun 2014 Measurement of Loudspeaker Radiation Pattern with Matlab Implementation Radiation pattern measurement of a loudspeaker. Author: Hristo Zhivomirov Michael

10 Jun 2014 Measurement of Loudspeaker Frequency Response with Matlab Implementation Frequency response measurement of a loudspeaker. Author: Hristo Zhivomirov Michael

26 Feb 2014 Inverse Short-Time Fourier Transformation (ISTFT) with Matlab Implementation Time-Frequency resynthesis via Inverse Short-Time Fourier Transformation (ISTFT) Author: Hristo Zhivomirov Yousef

Hi Hristo,
Your comment was very helpful.
Thank you so much.

25 Feb 2014 Inverse Short-Time Fourier Transformation (ISTFT) with Matlab Implementation Time-Frequency resynthesis via Inverse Short-Time Fourier Transformation (ISTFT) Author: Hristo Zhivomirov Zhivomirov, Hristo

Hi Yousef,

First of all thank you for the comment and for your interest in my submission.
Now here is the answer:

1) choose h = wlen/(4*n), where n = 1, 2, 3, ... (h = wlen/2 does not meet OLA-constraint, check with WindowChoice.m).
2) choose nfft = wlen (nfft > wlen cause interpolation in the time domain of every signal segment = errors in resynthesis, so if you really want interpolation you must use zero-padding technique in time-frequency domain).

Try this:

clear, clc, close all

% define signal parameters
% sine-wave signal (stationary signal)

fs = 48000;
t = 0:1/fs:1-1/fs;
x = 10*sin(2*pi*t*10);

% define analysis and synthesis parameters
wlen = 64;
h = wlen/4;
nfft = wlen;

% perform analysis and resynthesis
[stft, f, t_stft] = stft(x, wlen, h, nfft, fs);
[x_istft, t_istft] = istft(stft, h, nfft, fs);

% plot the original signal
figure(1)
plot(t, x, 'b')
grid on
axis([0 1 -15 15])
set(gca, 'FontName', 'Times New Roman', 'FontSize', 14)
xlabel('Time, s')
ylabel('Amplitude, V')
title('Original and reconstructed signal')

% plot the resynthesized signal
hold on
plot(t_istft, x_istft, '-.r')
legend('Original signal', 'Reconstructed signal')

Best Regards,

Hristo Zhivomirov

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