Authorization Profile for Background Users 
The background user needs the following authorization profiles:
In the BW system:
S_BI-WHM_RFC (Business Information Warehouse: RFC users in the Warehouse)
In the Source System:
S_BI-WX_RFC (Business Information Warehouse: RFC users in extraction)
In both the start menu of the BW system and the source system, choose the path and assign the profiles to the background user.