Bluetooth Low Energy

Description

Someone you know swears by analog signal processing. To demonstrate to her the benefits of digital signal processing, you decide to challenge her: she has to transmit Bluetooth Low Energy announcements on each of the announcement channels, while you only have a software defined radio (SDR) to capture them all.

You then show her that by disabling the anti-aliasing filter on the input stage, you can capture all communications.

The provided capture (ble.sig) has been by deactivating the anti-aliasing filter, at the central frequency 2461MHz, and with a sampling rate of 20MHz.

Note 1: The file format is an IQ capture, where each sample I and Q is a 32-bit float number. Standard signal processing softwares have no problem to handle this format. Note 2: To open this file with numpy, you need to use complex64: numpy.fromfile(<filename>, dtype = numpy.complex64). To use GNURadio, you need to use the block File Source and the complex format. Note 3: To start the analysis, you can first use the flowgraph provided with GNU Radio.