Qualcomm Researcher interview questions

I learned about this position from the forwarded email sent from their senior engineer to the professor at my school. The group is working on integrating GPS into vision aided INS on mobile phones. I send my cv and resume to the engineer directly, and after a few days, the HR scheduled a phone interview for me with the engineer and asked me to registered online. The phone interview went about 40 mins. Mainly asking about what I've learned from some of the relevant courses. He specifically asked me to explained what I've learned about INS since I was taking INS class during that semester. The only question that pop up was: How to integrate external information with INS? The whole process (apply - phone interview - rejected) took about 3 -4 weeks.