Getting started with Qualcomm reference designs
As someone who has been in the electronics sales and distribution world for a couple years now, I can say from experience that the majority of mobile handset chipset suppliers such as Qualcomm have their documentation on a secure portal and will only grant access to either top tier customers or other tier 1 customers that sign NDAs where the suppliers feel that the customer is a strategic partner.  Otherwise, you're left dealing with a SoM vendor such as Intrinsyc.