signal to noise ratio

I have a series of data in excel file showing the phases of currents and data is actually given by PMU's.I have to calculate signal o noise ratio for that data.No of rows are 36001.i have to check for different conditions of phases i.e for their signs.Can any one help me how to do this?

[Robert U]

Same here already:

https://de.mathworks.com/matlabcentral/answers/445911-snr-of-a-signal