How to best separate my signal into frequency regions?

I have a signal with frequencies betwwen [0.5,500] Hz and i want to create a filter to best separate the signal in the following regions:

1. [0.5-3]Hz
2. [3-8]Hz
3. [8-13]Hz
4. [13-30]Hz
5. [30-500]Hz

My questions are:

1. How can i find the sampling frequency if i know that the signals are 'downloaded' in Europe (energy transport network of 50Hz)
2. Whats the most appropriate computational method to separate the signal in the regions.

I think that in order to find the sampling frequency i need to find the max frequency of my signal and then fsampling=2*fmax.Does the information about the 50Hz network affects my sampling frequency?

• what do you mean with "downloaded"? Recorded? Jan 15, 2018 at 19:13
• I have a lengthy answer ready to be typed down, but I don't want to waste my time on something that you don't need. So please be far more detailed! What is your signal? Why do you need to separate it in frequency ranges? Why do you even mention the grid frequency? That doesn't happen out of thin air, so you're not giving us even half of the background and info you should! Jan 15, 2018 at 19:18
• I have an EEG signal and I need to extract the alpha beta theta and delta regions.This is the last year exam in DSP course in my university. I think tha the grid frequency is given in order to find the sampling frequency.I don't have the signal but a theoretical answer would help me a lot . Jan 16, 2018 at 7:48
• Yes my mistake , I mean recorded. Jan 16, 2018 at 7:49
• @Thanos you should always update/improve the question when you answer comments so they gain visibility Jul 15, 2018 at 20:20