Mastering Software Defined Radio (SDR): GNU Radio and SDR++

Explore the history of cellular networking from analogue systems to GSM, highlighting mobility management, handoffs, roaming, and the shift from circuit switching to IP-based networks.

Explore the evolution of global telecommunication standards, from ITU and SS7 to GSM and 3GPP, and compare circuit-switched speeds with modern IP and Ethernet networks.

Explore how SS7 enables call setup and teardown across traditional and IP networks. Examine the SS7 stack, including MTP1–MTP3, ISUP, SCCP, and STPs, plus SSPs and SCPs routing.

Explore the GSM SS7 signaling stack, including MAP, HLR, MSC, ISUP, and BSSMAP/DTAP, and compare IP-based Sigtran with traditional MTP for call setup and routing.

Explore how the visitor location register and home location register manage subscriber data, location tracking, service authorization, and roaming in GSM networks, using IMSI and MSISDN.

Install GNU radio on ubuntu linux, build flow graphs in GRC, connect blocks, feed data, and output to speakers or files; consider virtualization or conda for non-linux use.

Learn to use the GNU Radio Companion interface to build signal processing flow graphs by dragging and connecting blocks. Configure sources, sinks, and other blocks to run real-time simulations.

Explore how source blocks and sink blocks drive the data flow in a GNU radio companion flow graph, using file, signal, or constant sources and audio or file sync outputs.

Save your work, run the GNU Radio Companion flow graph in Radio Companion, fix red errors, and observe the waveform to learn basic signal processing with complex numbers.

Build a basic am receiver with GNU Radio Companion using pre-recorded data, configure the P2 GUI entry blocks, samplerate, and understand integer vs float data types and exponential notation.

Add a file source to the GNU radio flow graph to simulate real radio signals, then connect processing blocks (signal source, multiply, low pass filter, am demod, resampler) and save.

Set up audio sync block at 32 kHz, connect it to rational sampler block, and adjust the sample rate variable to propagate changes and hear the am radio through speakers.

Explore frequency concepts, filters, and gain behind an am receiver, then generate and listen to a 500 Hz tone in GNU Radio to understand how signals are represented numerically.

Visualize a 500 Hz sine waveform in real time with a time sink, linking time-domain behavior to frequency, amplitude, and phase. Use a GUI slider to explore aliasing and Nyquist.

Explore the frequency domain and how the Fourier transform and FFT reveal a signal’s components, from a pure tone to complex music.

Merge three sine tones into a complex signal with an ad block, and visualize the time and frequency domains to identify peaks at 523.25 Hz, 1318.5 Hz, and 1568 Hz.

Explore real world sounds, focusing on a human voice, and learn to analyze them in time and frequency domains using a flow graph, wav file source, and FFT in SDR.

Explore how gain amplifies sound and radio signals in a GNU Radio Companion flow graph, showing how multiplication by a constant boosts amplitude while preserving shape.

Use filters to refine the received signal by suppressing unwanted frequencies, preserving the desired passband, and learn four types—low pass, high pass, bandpass, and band reject—with cutoff frequency considerations.

Create a three-band equalizer in GNU Radio Companion, controlling low, mid, and high gains with sliders and outputting both audio and a real-time spectrum visualization.

Master radio tuning isolates a target signal by frequency shifting and filtering in SDR flow graph, using FFT to center it at zero hertz, as shown in GNU Radio Companion.

Learn to shift radio signal frequencies in GNU Radio Companion by multiplying data with a complex sinusoid of variable frequency, visualize the shifted spectrum, and tune to a target frequency.

Learn how SDRs manage real world frequencies and zero centered processing, using a center frequency to translate user tuning into internal DSP terms for accurate signal analysis.

Create a tunable am receiver in GNU Radio by building a flow graph with a file source, frequency shifting, and a low-pass filter to demodulate an am station.

Demonstrates how the AMD mode block demodulates AM signals by removing the carrier, extracting the audio, and converting complex radio data to float audio for playback.

Learn how decimation and interpolation drive resampling in a GNU Radio flow graph, bridging 400 kHz audio to 32 kHz playback with rational resampling.

Explore how the throttle block, or tradeblock, enforces a specific data rate in synthetic GNU Radio flow graphs to prevent CPU overuse and maintain consistent 32 kilo samples per second.

Discover how software defined radio moves signal processing from analog hardware to software. Explore RTL-SDR receivers around the RTL 2832 U chip that enable wideband tuning and accessible radio experiments.

Compare RTL-SDR and HackRF by detailing RTL-SDR specs (22–2200 MHz, 3.2 MHz bandwidth, 8-bit ADC, ~50 dB dynamic range, <4.5 dB noise) and HackRF's half-duplex transmit capability.

Download and configure SDR Plusplus, open source cloud platform for software defined radio that supports rtl, sdr, hack, rf, isp devices, with nightly builds for windows, linux, and raspberry pi.

Set up your SDR receiver with SDR Plus+, install drivers, connect RTL-SDR or HackRF, and tune gain, AGC, sample rate, bias, and offset modes for optimal reception.

Navigate the SDR++ main screen, master the top bar and side menu for start/stop, volume, frequency, and SNR, and tune precisely via spectrum and waterfall.

Explore HDR plus plus main menu to customize spectrum and waterfall displays with FFT visualization, color maps, and band plans. Tune modulation modes, filters, and squelch for clear reception.