Costas Loop for Carrier Phase Synchronization

Output from the Costas Loop block after phase convergence

Costas loop is a carrier phase synchronization solution devised by John Costas at General Electric Company in 1956 [1]. It had an enormous impact on modem signal processing in general and carrier synchronization in particular. At that time, it was…
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A Real-Imaginative Guide to Complex Numbers

Plots for positive integer powers of x in 3D

June 18, 2020 On a cold morning in August 2015, I narrowly missed a train to my office in Melbourne city. With nothing else to do in the next 20 minutes, my mind wandered towards an intuitive view of complex…
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The Big Picture of Localization

Two way transmission

Digital Signal Processing (DSP) enables us to find the range of a device transmitting a wireless signal with a particular structure under some conditions. To understand how this process works, we need to look at the big picture of a…
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FSK Demodulation in GNU Radio

Flowgraph output

One of the most useful modulation techniques in applications requiring low receiver complexity is Frequency Shift Keying (FSK). In an FSK scheme, digital information is transmitted by changing the frequency of a carrier signal. Binary FSK Binary FSK (BFSK) is…
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