What are the signal processing techniques to extract a low amplitude single/ multiple source signal from the received noisy signal?

I am having a received low SNR signal. It can contain upto 3 sources of signal, each of which has a different dominant frequency (say 1GHz for source 1, 1.5 GHz for source 2, 2 GHz for source 3)....

29 September 2018 1,845 11 View