Software Assisted Digital RF Processor (DRP™) for Single-Chip GSM Radio in 90 nm CMOS

This paper proposes and describes a new software and application programming interface view of an RF transceiver. It demonstrates benefits of using highly programmable digital control logic in an RF wireless system realized in a digital nanoscale CMOS process technology. It also describes a microprocessor architecture design in Digital RF Processor (DRP™) and how it controls calibration and compensation for process, temperature and voltage variations of the analog and RF circuits to meet the required RF performance. A few calibration examples to reduce a DCO bias current and improve device reliability, as well as to optimize transmit modulation and receive performance, are given. The presented circuits and techniques have enabled successful implementation of a commercial single-chip GSM radio in 90 nm CMOS.