A noisy signal has been uploaded to D2L in the files fft_signal. mat and fft_signal. txt. Write a program to estimate the power spectral density of the signal and determinethe frequency components used to construct it. Submit your code along with yourassignment. You can compare against the Matlab® built-in function pwelch to makesure your code is working properly. Note: All of the functions you will need forwindowing and computing FFTs are built into Matlab®. Your primary task will beto write the logic/loops required to use them to replicate the behavior of pwelch (i. e. power spectrum using segmenting and windowing). You can use a window size of 256.

Answer: Program to estimate the power spectral density of the signal

Explanation:

fs = 4000; % Hz sample rate Ts = 1/fs; f0 = 500; % Hz sine frequency A = sqrt (2); % V sine amplitude for P = 1 W into 1 ohm. N = 1024; % number of time samples n = 0:N-1; % time index x = A*sin (2*pi*f0*n*Ts) +.1*randn (1, N); % 1 W sinewave + noise

Spectrum in dBW/Hz

nfft = N; window = rectwin (nfft); [pxx, f] = pwelch (x, window, 0, nfft, fs); % W/Hz power spectral density PdB_Hz = 10*log10 (pxx); % dBW/Hz

Spectrum in dBW/bin

nfft = N; window = rectwin (nfft); [pxx, f] = pwelch (x, window, 0, nfft, fs); % W/Hz power spectral density PdB_bin = 10*log10 (pxx*fs/nfft); % dBW/bin