Math-Based RF System Architectures

In this presentation a disruptive approach to designing Radio Frequency Front-End (RFFE) architectures is investigated. This methodology addresses the critical challenges of complexity, efficiency, and linearity, providing system-level solutions that enable low power consumption, high energy efficiency, and wideband operation. The application of Walsh theory across the entire RF chain enables signal processing from digital to analog and from baseband to RF within the sequency domain, which inherently supports diversity, parsimony, and binary features.

A fully Walsh-domain RFFE implemented in 28nm FDSOI CMOS technology was developed. The system integrates a Walsh-based RF digital-to-analog converter (WDAC) and a Walsh-based RF analog-to-digital converter (WADC) designed for digital predistortion (DPD) applications. These components demonstrate breakthroughs in energy efficiency, achieving sub-pJ/bit performance and supporting ultra-wide bandwidths of up to 5 GHz. An experimental demonstration validates the concept, showcasing wideband, power-efficient signal processing and underlining the promise of operating entirely in the Walsh basis as a viable strategy for future low-power, high-throughput wireless systems. The approach combines energy efficiency with wideband capability, offering a compelling alternative to traditional architectures. The concept of math-based system design is compatible with the full range of spectrum access, from FR1 sub-6 GHz and direct-conversion 5G systems to FR2 and FR3 for 6G, including sub-15 GHz bands with carrier aggregation and sub-THz bands with direct access potential at 150 GHz and 20 GHz bandwidth. The proposed architecture paves the way toward industrial implementations in next-generation 6G wireless transceivers.