How to do analysis of bispectrum results?

I am doing project on signal detection using bispectrum.In this i am takin a signal using two frequecies(like one frequency at 4k and another frequency at 7k.sampling freq-18k) and adding random noise to this signal.after implementing power spectral analysis and bispectral analysis to the signal, am able to detect the signal at the given frequencies for power spectrum but for bispectrum m not able to analyze the result at the given frequency.and also compared to power spectrum bispectrum strength is decreasing.why it is coming like this?plz help me.

Answer 1

[UDAYA PEDDIRAJU]

Hi Bijaya,

To analyze bispectrum results in MATLAB, you can follow these steps:

1. Create your own implementation to compute the bispectrum of your signal.
2. Use contour plots or 3D surface plots to visualize the bispectrum.
3. Look for peaks in the bispectrum that correspond to the frequencies of interest.

Regarding the decrease in bispectrum strength compared to the power spectrum, this can occur due to several factors, including noise affecting the non-linear interactions captured by the bispectrum. The bispectrum is sensitive to phase relationships, and noise can obscure these relationships, leading to lower bispectrum values.

The following file exchange files might help you:

1) https://www.mathworks.com/matlabcentral/fileexchange/60-bisp3cum

2) https://www.mathworks.com/matlabcentral/fileexchange/13476-bispectr.