Garrett Vanhoy

OSSIE/GNU Radio Generic Component

A Generic Component (GC) was developed to combine the functionalities of OSSIE and GNU Radio (GR), two widely used platforms for Software-Defined Radio. The GC is an OSSIE component which can encapsulate one or more GR blocks in a flowgraph and provide the necessary data conversions to interface OSSIE I/O with the GR blocks. The GC was designed to be able to reconfigure the encapsulated flowgraph and the relevant block properties in near real-time. Preliminary latency tests were performed on the GC to compare three different I/O interfaces between OSSIE and GR. All three interfaces average below 20% added processing time, and the fastest interface (message queues) was implemented as the default. The results demonstrated that the overhead imposed by the GC itself does not contribute to significant latency. Possible applications for the GC are discussed.

A Spatial Interpolation Method for Radio Frequency Maps Based on the Discrete Cosine Transform

Estimating radio frequency (RF) power in a geographic area is almost as old as wireless technology itself. It is crucial to anyone who is working or doing business with wireless technologies: wireless operators, the military, regulators, etc. Under a cognitive radio paradigm, spectrum usage is no longer static and is migrating towards dynamic and shared access paradigms. Enabling this evolution requires the estimation of the Radio Frequency map (RF map) of a given area. A variety of methods have already been proposed and tested to accomplish this estimation by leveraging decades of work on spatial interpolation methods. In this work, we justify, through analysis and simulation, using the Discrete Cosine Transform (DCT) as a more dynamic and accurate interpolation technique through comparison to other deterministic methods such as the Inverse Distance Weighting (IDW) method.