Seamless Dynamic Runtime Reconfiguration in a Software-Defined Radio

Abstract

We discuss implementation aspects of a software-defined radio system that allows for dynamic waveform reconfiguration during runtime without interrupting dataflow processing. Traditional software-defined radio systems execute a waveform statically, exactly as it is programmed. Reconfiguration is provided by executing a different waveform, which requires the system to stop processing data while reconfiguration occurs, and also may incur an unacceptable delay for some applications. Recent research has demonstrated basic reconfiguration by programming multiple branches into a waveform and dynamically switching between branches. This technique requires redundant resources and in general cannot be expanded to encompass all possible waveforms of interest, but, if implemented carefully, could be made to seamlessly process data. We propose a system that allows for dynamic insertion and removal of entire waveforms, individual constituent blocks, and block algorithm implementations tailored to specific processors. Our system performs this reconfiguration while maintaining processing state, seamlessly without interrupting data-processing, and with only the resources necessary for the given waveform and processors. In order to leverage this new level of reconfigurability, we created a new system component: a supervisor. This system supervisor monitors the state of each processor and waveform execution, and moves computations among available processors as their loads, capabilities, and block algorithm implementations allow. An example using a simple supervisor is provided to demonstrate the effectiveness of our system.

Inspecting GNU radio applications with controlport and performance counters

“…One of Surfer's purposes is to use a supervisor to collect runtime statistics such as throughput, latency, processor load, etc. and make decisions to dynamically adjust the radio [3].…”

On the use of an algebraic language interface for waveform definition

“…By using template classes for all blocks, Surfer avoids code redundancy and related bug duplication issues, and also allows for easier debugging of code issues because the source is directly available as a header file. That said, explicit-typed SALINE functions and Surfer blocks can be created and utilized through the use of Surfer's signalprocessing flavors [10]. This paper is closely related to a same-titled one presented at SDR'11 WInnComm US [13], but with some additions are two notable changes.…”

“…Our Surfer SDR framework aims to enhance the user's experience by pushing complexity into the framework's programming [10]. Continuing this trend from the perspective of reducing the user's learning curve for creating script-based waveforms, we augmented Surfer to provide an alternative, algebraic-like language interfaceusing a buffer-centric approach similar to that provided by MATLAB and Octave.…”