Signal routing API for a digital front-end System-on-Chip

Abstract

The digital predistortion (DPD) system within the digital front-end (DFE) System-on-Chip (SoC) employed in mobile base stations represents a complex signal processing architecture that requires precise specifications for signal routing and processing to function as intended. Due to the inherent constraints of ASIC (Application-Specific Integrated Circuit) circuits, which offer limited hardware resources, the routing of signal paths within the DPD processor subsystem may need to be dynamically adjusted to accommodate different usage scenarios effectively. Furthermore, given the desire to support multiple algorithmic options within DPD, the flexibility of signal path routing becomes essential. Manually altering routing paths through configuration files and software interfaces is laborious and slow. Additionally, the lack of visualization can further impede the process, as understanding the structure of the signal path within a complex signal processing system from a text file can be challenging. The result of this thesis is an API (Application Programming Interface) that enables an abstraction layer where the user only needs to define the inputs for the signal processing units from the possible incoming signals in the system, as well as individual settings that determine the operation of these units. The product also provides a tool that graphically visualizes the selected signal routing. The functionality of the API was tested through unit tests, which achieved 87% coverage of the API’s codebase.