What is the difference between between the numeric, analogic and hybrid Beamforming?
This may help:
This is a little bit old note but I hope it can be a starting point:
http://www.sharetechnote.com/html/Handbook_LTE_BeamForming.html#Beamforming_in_LTE
For real application like application to 5G, I hope this may help:
http://www.sharetechnote.com/html/5G/5G_CSI_RS_Codebook.html