PhD Defense: "Direct-Sequence Spread-Spectrum Techniques at The Antenna with CMOS SOI"

Hussam Alshammary

December 12th (Thursday), 10:00am
Engineering Science Building (ESB), Rm 2001

This talk provides an overview of challenges of modern wireless communications including frequency spectral efficiency, multiple-path fading, hardware complexity and un-utilized white spaces in the spectrum. By using Direct-Sequence Spread-Spectrum(DSSS) codes it is possible to overcome some of those challenges. Full-Duplex systems are improved with DSSS techniques by increasing the rejection of the Self-Interference form co-located transmitter as well as rejecting the TX replicas before and post the antenna. Out of band jammres are rejected as well relaxing the linearity requirementsof the receive chain significantly. Carrier Aggregation is possible with DSSS at a much lower power consumption and hardware complexity as well as much faster settling time.Spectrum Sensing to detect unused spectrum frequencies is achieved with DSSS at lower power consumption. A frequency diversity technique is introduced to overcome the fadingof wireless channel. To support theoretical analysis, experimental verification with CMOS SOI is discussed in detail and several designs are included.

About Hussam Alshammary:

Hussam Alshammary is a Ph.D. candidte in electrical and computer engineering at the University of California at Santa Barbara, Santa Barbara, CA, USA. In 2015, he joined James F. Buckwalter’s group at the University of California at Santa Barbara. His current research interests include RF/mixed-signal integrated circuit design and CMOS signal processing techniques.

Hosted by: Professor James F. Buckwalter