Processing signals need a lot of expertise and you have to be sure that you are aware of the core principles that govern the usage. We have some of best signals & Systems video lectures which will teach you about the core details of the different aspects of signal processing.
Digital communications and digital signal processing are two broad topics that we have discussed in thorough details. When you want to make an estimate of the signals, you can find video tutorials devoted to the same as well. With wireless communication and communication engineering, you will learn some of the most important concepts.
The Fourier transform is one of the basic theorems which have widespread applications. We have one whole series of online videos devoted to Fourier transform and these lectures will guide you with the basics of the theorem.
Signal processing is an extremely wide topic and we have online lectures focused upon adaptive signal processing.