RF/Microwave Mobile Communications Laboratory
Dr. Shawn Stapleton and Dr. Jim Cavers

The Mobile Communications Laboratory highlights the physical and data link levels of mobile and personal communications. This focus reflects the enthusiasms and expertise of its two principals, Shawn Stapleton and Jim Cavers. Their continuing research collaboration has resulted in a convergence of digital signal processing (DSP) and radio frequency (RF) design methods, with a generous mixture of modulation, detection and coding theory thrown in.

Over its ten-year history, the Mobile Communications Lab has given birth to many innovative designs, several of which are in commercial use. One example is the linearization of power amplifiers: the lab was home to one of the world's first adaptive digital predistorters, the world's first adaptive baseband analog predistorter, the world's first jointly adaptive predistorter and quadrature modulator and the world's widest bandwidth feedforward linearizer. Another example is RF IC design, in which many novel GaAs MMICs were designed and later used by industrial groups.

A new thrust in adaptive antenna arrays for cellular and PCS applications has already yielded theoretically and commercially promising results. For example, joint detection combined with diversity promises to dramatically increase the capacity of TDMA systems. Similarly, coded polarization diversity provides significant improvement over single links. System layout for indoor CDMA - currently a "black art" - is the subject of another analysis, one that will result in design guidelines that decrease the time and cost of base station placement.

Facility

Researchers

Current Research Projects

Recent Publications