3) Signals and Systems –

Classification of systems and signals:-

System modelling in terms of differential and difference equations:-https://www.youtube.com/watch?v=XrNi0vlgFRA
Fourier series:-https://www.youtube.com/watch?v=lkAvgVUvYvY
State variable representation:-https://www.youtube.com/watch?v=ibhwKT6l_Os
Fourier transforms and their application to system analysis:-https://www.youtube.com/watch?v=EdIzr4jluF4
Convolution and superposition integrals and their applications:-https://www.youtube.com/watch?v=1pJ5ie2hX1M
Laplace transforms and their application to system analysis:-https://www.youtube.com/watch?v=91hV7LsRUTI
Z-transforms and their applications to the analysis and characterisation of discrete time systems:-https://www.youtube.com/watch?v=eCcg4rQMRYI
Correlation functions:-https://www.youtube.com/watch?v=_r_fDlM0Dx0
Random signals and probability:-https://www.youtube.com/watch?v=HbK5jgy0_zA
Response of linear system to random inputs:-https://www.youtube.com/watch?v=HbK5jgy0_zA
Spectral density:-https://www.youtube.com/watch?v=0bs6nnVoG5Q

standard book
alan v OPPENHEIM and alan s willsky with habib nawab:-http://www.sjbit.edu.in/app/course-material/ECE/IV/SIGNALS%20%26%20SYSTEMS%20%5B10EC44%5D/ECE-IV-SIGNALS%20%26%20SYSTEMS%20%5B10EC44%5D-NOTES.pdf