Low-Cost Digital Beacon Receiver Based on Software-Defined Radio

In this paper, we present a low-cost digital beacon receiver based on software-defined radio. A free software toolkit, GNU radio, was used to develop the beacon receiver´s functionality. The hardware used was a parabolic antenna, a low-noise block converter, an Ettus universal software-radio peripheral, a Linux PC, and a Global Positioning System receiver. The total hardware cost of the developed beacon receiver was low compared to commercially available analog receivers. To validate the receiver, we compared the measured preliminary results of amplitude scintillation at 11.2 GHz with reported theoretical models. Comparisons between the measured values and the ITU-R model for the amplitude-scintillation distribution showed that the ITU-R model somewhat underestimated the statistic. The measured probability density function was also compared with the Moulsley-Vilar model. For small log-amplitude values, the Moulsley-Vilar model fit the measured statistic well, but slightly overestimated the statistic for large log-amplitude values. Good agreement was found between the measured and theoretical power spectral density of amplitude scintillation. The diurnal variation of the amplitude scintillation´s standard deviation was calculated. It was largest at noontime, which was consistent with previously reported measurement results. To some extent, this may validate the performance of the developed receiver. The developed software is available from a software repository (http://www.sourceForge.net). enabling collaboration, development, and use of the software.