Qualcomm interview questions

One phone interview: what is qpsk/ offset qpsk? what are channel coding and source coding? Two signals transmitting form same antenna at same power, which will have better range.. 1800 or 1900? What is rf wave propogation, free question, explain whatever you know! what is OFDMA? how it is different from CDMA? Communication circuit block diagram, source to antenna..

one round of phone interview followed by 5 rounds of onsite interview. Phone interview was basic digital comm questions. In onsite interview, 1st round was about my work ex, second round was on resume and random processes, third and fourth interview was on digital comm completley, fifth was gen talk - not much questions asked