ISBN 9783843939782

978-3-8439-3978-2, Reihe Elektronik

Moritz Schrey
A Contribution to System Partitioning and Interface Optimization for Wireless Systems

164 Seiten, Dissertation Rheinisch-Westfälische Technische Hochschule Aachen (2019), Hardcover, A5

Zusammenfassung / Abstract

The thesis introduces interfacing and partitioning aspects of wireless transceivers, which ought to be carefully evaluated during system design phase or which might show up unexpectedly otherwise during implementation phase. Design and implementation of wireless systems is realized using a modular approach along the signal path. Each functional block arises from partitioning the system into submodules. Identifying each block and defining interfaces between them and towards means of configuration helps to achieve an overall system design which is low on cross-dependencies, fit for the intended purpose and which uses resources wisely.

The kogLTE project is introduced. A detailed description is given of kogHF, the frequency converter module of the kogLTE project. System considerations, module partitioning issues and implementation details are elaborated. By means of the chair’s and the author’s contribution within this project, important aspects of how this system was divided up to the different project partners as well as implications from these decisions are highlighted. Payload data interfaces as well as configuration and control interfaces are defined on a logical as well as electrical and protocol level. Interfaces between submodules created by the division into modular blocks as well as their implementation are described in detail. Advantages and disadvantages of the chosen implementation details are given.

The CyberRF ASIC is presented in detail as a chip-level example of the importance of interface design. Disadvantages of nonideal interfaces are analyzed. Interface additions or extensions such as Interrupt Request lines are implemented and their implications discussed. Trade-offs between flexibility and performance are introduced with regard to several wireless protocol features such as Address filters, Frame Check Sequences, Automatic ACK transmission etc. It is shown how proper system partitioning leads to possible reuse of certain functional blocks, extending their use and facilitating low-effort functional extensions. Extending the interface from an electrical to a software-based realization, the implementation of a Linux kernel device driver for the CyberRF transceiver is presented, by which a Linux network interface wpan0 is created. This device driver proves self-containedness, usability and ease-of-use as well as providing a properly abstracted customer interface, adhering to well-defined and well-accepted de-facto standards.