Evolution of Cellular Wireless Technology: 1G to 5G

Evolution of Cellular Wireless
Technology: 1G to 5G

Time: 3 pm – 4 pm, October 1st (Tuesday)

Location: Bossone 302, Drexel University



Over the last four decades (1980-2020), cellular wireless technology has revolutionized the communication industry and transformed the lives of people. From its infancy, with the advent of 1G (AMPS), to the pinnacle, with the successful deployment of 5G (mmWave)cellular wireless communication overcame many challenges. Dr. Gudem led the development of multiple generations of cellular transceivers from the dawn of 3G to the dusk of 4GIn this seminar, Dr. Gudem will take the audience through an intimate journey that highlights the many successes and a few missteps over his two-decade career in the cellular wireless industry. 

Dr Gudem co-invented the IntelliCeiver technology that enabled deployment of diversity and MIMO in early generations of 3G cellphones. This improved data throughput without significant increase in power consumption and BoM in RFR6500, a flagship product that exceeded over 100 million in volume shipments. Subsequently, Dr. Gudem led the development of the RF cellular transceiver in several generations of System on Chip (SoC) products. His research and patents led to the elimination of interstage SAW filters in QSC1100 and all future Qualcomm products. This challenging problem plagued the industry for five generations of 3G CDMA handsets. Despite much hype in the industry regarding SoCs, subsequent generations of cellular products saw the disintegration of SoC and even the disintegration of the transceiver into external LNAs followed by an I/Q Vector Modulator/DemodulatorDr. Gudem will highlight the key market changes that forced the cellular industry to abandon SoC and traverse the path of disintegration.  

Dr. Gudem’s industry leadership led to one of the rare industry flip-flops, where cellular receivers and transmitters went from single-ended RF input/output to differential then back to single-ended. Dr. Gudem will elaborate on how the explosion of cellular bands from approximately four in 3G/CDMA to over seventy in 4G/LTE precipitated this change. More recently, Dr Gudem led the development of the world’s first 28nm transceiver (WTR3925) that supported receiver carrier aggregation and 4×4 MIMO in 4G/LTE along with the legacy 2G/3G. WTR3925 revolutionized the industry in power consumption, formfactor (3x smaller than previous generations) and BoM. It was used in iPhone 6/7, Samsung galaxy S7/S8 and other top-tier cellphones and sold over 800 million parts. Prior to joining UCSD, Dr. Gudem led the development of SDR855, the most advanced 14nm transceiver that supported carrier aggregation across five bands along with 4×4 MIMO. This chip made its debut in Samsung galaxy S10 commercialized in 2019.  Many more cellphones with SDR855 are expected to be deployed in 2019-2021.  



Prasad Gudem received a B. Tech degree in Electrical Engineering from the Indian Institute of Technology, Madras, India in 1988 and a Ph.D. degree in Electrical Engineering from the University of Waterloo, Waterloo, Ontario, Canada in 1996. He was Vice President of Engineering at Qualcomm until 2018 and led the development of multiple generations of cellular transceivers that sold over three billion chips and used in top-tier products such as iPhone, Samsung, etc. Dr. Gudem was instrumental in establishing the Qualcomm RFIC group in Bengaluru that developed low-tier transceivers which sold over one billion parts. He is currently an Adjunct Professor in the Department of Electrical and Computer Engineering, University of California at San Diego, La Jolla, CA, USA. He has 50+ patents and 40+ IEEE publications. He has taught several graduate-level classes and co-advised 12+ Ph.D. students and a recipient of the Graduate Teaching Award.