Normally we are facing ICM band high in Combine DAS (IBS),
1. due to connector not done in proper manor.
2.which you used accessories for DAS that accessories not meeting PIM value.
3.Fq interface in from the BTS end
4.if we have DAS connectivity in Inside the BTS room then you need to reduce the BTS room radiation.
Diffrent B/W MIMO & SISO: in single word we can say,MIMO means multi input multi output ,,,SISO single input single output