YouTube desktopSDR Videos
The desktopSDR YouTube Channel hosts the videos shown below, which are linked from the book to demonstrate what you should expect to see when carrying out some of our practical SDR examples and exercises in MATLAB®. For many of the examples, we will present either; a screen video that shows what the user should see, or a more involved video that demonstrates desktop hardware in action.
For best results, turn on 1080p streaming and watch in full screen 🙂
Support Package Installs and Software Setup:
RTL-SDR Hardware Support Package Installation
USRP® Hardware Support Package Installation
MATLAB Environment Setup
First use of the RTL-SDR in MATLAB and Simulink
Exploring the Spectrum:
The FM Radio Band
GSM Field Test Mode & Phonecall
UMTS Field Test Mode & Videostream
SRD Garage Door Keyfob
SRD Car Keyfob
DVB-T TV Broadcast
DAB Radio Broadcast
Desktop Amplitude Modulation (AM):
DSB-TC Envelope Detector Demodulator
DSB-SC Envelope Detector Demodulator
SSB Complex Sine Wave Demodulator
Phase Locked Loop Demodulator
Costas Loop Demodulator
Desktop Frequency Modulation (FM):
Complex Frequency Discriminator Demodulator (Mono)
Complex Frequency Discriminator Demodulator (Stereo)
AM in FM Demodulator
FM FDM Demodulator
Desktop Quaternary Phase Shift Keying (QPSK):
Coarse Frequency Synchronisation
Timing and Phase Synchronisation
ASCII Message Receiver
Greyscale Image Receiver
Desktop Data in FM:
ASCII/ Audio Receiver
Image/ Audio Receiver
RTL-SDR Hardware Support Package Installation top
In this video we show you how to add the RTL-SDR Hardware Support Package to your installation of MATLAB, and check that the installation is working correctly.
MATLAB Environment Setup top
This video demonstrates the steps required to configure the MATLAB path to include our custom Simulink Library, scripts and callbacks folder. Without completing these steps, you will encounter issues when trying to work through the exercises in the book.
First use of the RTL-SDR in MATLAB and Simulink top
In this video we run through Exercises 2.5 and 2.6 to demonstrate how to use the RTL-SDR in both MATLAB and Simulink.
Exploring the Spectrum: The FM Radio Band top
The focus of this video is to show you what an FM Radio signal looks like, and how it interacts with the spectrum. We also demonstrate how to use a MATLAB GUI (graphical user interface) to control the RF front end of the RTL-SDR, and show you how the DSP System Toolbox Spectrum Analyzers can be used to detect signals.
Exploring the Spectrum: GSM Basestation top
In this video, we show you what you would expect to see if you tuned your RTL-SDR to GSM uplink and downlink channels. We explain a little about the GSM signal structure and spectra, and discuss the differences between uplink and downlink channels.
Exploring the Spectrum: UMTS Basestation top
In this video we use the RTL-SDR to look at UMTS downlink channels. These channels are wider than the bandwidth of the RTL-SDR, meaning that they have to be viewed in stages.
Exploring the Spectrum: LTE Basestation top
In this video we show you what you should see if you tune your RTL-SDR to an LTE channel. We discuss a little about the signal structure, and examine LTE guard bands too.
Exploring the Spectrum: GSM Field Test Mode & Phonecall top
In this video, we demonstrate placing a phone into field test mode to find out what uplink frequency it has been allocated, and tune an RTL-SDR and a professional spectrum analyzer to this frequency to watch what happens when a phonecall is made.
Exploring the Spectrum: UMTS Field Test Mode & Videostream top
Similar to the GSM Field Test Mode & Phonecall video, this video demonstrates how to place a smartphone into field test mode to find the UMTS uplink frequency it has been allocated. Tuning an RTL-SDR and a professional spectrum analyzer to this frequency, we are able to see what happens when we stream a video to the device.
Exploring the Spectrum: SRD Garage Door Keyfob top
In this video we demonstrate what happens when you press a button on a garage door keyfob. It transmits a signal at 433.9MHz, which can be received by the RTL-SDR, and viewed in Simulink!
Exploring the Spectrum: SRD Car Keyfob top
In this video we show you the signals that three different car keyfobs transmit. All operating at 433.9MHz, these keyfobs are for cars from three different manufacturers. Each keyfob transmits a unique signal, which will only unlock the car it is paired with!
Exploring the Spectrum: DVB-T TV Broadcast top
In this video we show you what a DVB-T channel looks like in the frequency domain. The COFDM signals contain over 1000 orthogonal subcarriers, and (in the UK) span an 8MHz channel. DVB-T channels are like ‘big versions’ of DAB channels (shown in the video below…)
Exploring the Spectrum: DAB Radio Broadcast top
This video shows what you would expect to see if you tuned your RTL-SDR to a DAB radio channel. These COFDM channels are 1.5MHz wide, which means that you will not need to retune your RTL-SDR to see all of channel. DAB channels are like ‘little versions’ of DVB-T channels (shown in the video above…)
Desktop AM: DSB-TC Envelope Detector Demodulator top
In this video we highlight some of the different hardware that can be used to generate AM signals, and demonstrate how the Complex Envelope Detector can be used to demodulate AM-DSB-TC signals.
Desktop AM: DSB-SC Envelope Detector Demodulator top
In this video we show you why an envelope detector cannot be used to demodulate an AM-DSB-SC signal!
Desktop AM: SSB Complex Sine Wave Demodulator top
The focus of this video is to illustrate how AM-SSB signals can be demodulated. Additionally, you will also get the chance to hear what happens when there is a frequency offset between the modulating carrier and the demodulating sine wave.
Desktop AM: Phase Locked Loop Demodulator top
In this video we use a Phase Locked Loop to demodulate an AM-DSB-TC signal.
Desktop AM: Costas Loop Demodulator top
The focus of this video is to demonstrate how a Costas Loop can be used to demodulate and recover an information signal from the transmitted AM-DSB-SC signal. Additionally, we show you what happens when you try to demodulate an AM-DSB-TC signal.
Desktop AM: FDM Demodulator top
In this video we implement a Frequency Division Multiplexing scheme to transmit and receive three audio signals simultaneously.
Desktop FM: Complex Frequency Discriminator Demodulator (Mono) top
In this video we highlight some of the different hardware that can be used to generate WFM radio signals, and in particular, discuss how inputting a baseband FM signal to the USRP results in an FM signal being transmitted. We also present the Complex Frequency Discriminator, and demonstrate this demodulator being used to recover an audio signal.
Desktop FM: Complex Frequency Discriminator Demodulator (Stereo) top
This video builds on the Mono FM video (above), incrementing both the transmitter and receiver designs to handle stereo FM signals. We discuss how a stereo FM encoder and multiplexer can be used to generate an FM MPX, and the process required to perform the reverse in the receiver.
Desktop FM: AM in FM Demodulator top
In this video we present our ‘AM in FM’ modulation scheme. Here, we pre-encode a mono audio signal in a way that will break the FM encoder/ multiplexer, resulting in an FM MPX that contains no mono component. Transmitting and receiving this signal, AM demodulators can be used to demodulate the stereo component to baseband. This technique can be used in situations where you wish to test out AM demodulators, but do not have an AM transmitter.
Desktop FM: FDM Demodulator top
In this video we investigate transmitting four audio channels simultaneously with an FM transmitter. Pre-encoding the four mono audio signals in a way that will break the FM encoder/ multiplexer, a customised FM MPX can be created that contains the four channels. In the receiver, after FM demodulation to recover the MPX, a filter bank and AM envelope detectors can be used to demodulate each of the channels back to baseband, where they can be output to the computer’s speakers.
Desktop QPSK: Pulse Shaping top
In this video, we discuss and demonstrate the benefits of using Pulse Shaping in a digital communications system. We focus on a Raised Cosine response, and implement this using a transmit and receive Root Raised Cosine filter pair.
Desktop QPSK: Coarse Frequency Synchronisation top
Coarse Synchronisation is a process performed to centre the received signal as close as possible to 0Hz prior to further synchronisation stages. This video demonstrates it in action on a QPSK signal.
Desktop QPSK: Timing and Phase Synchronisation top
In this video, we talk you through the full architecture of the Physical layer of the QPSK receiver. Covering coarse synchronisation, matched filtering, automatic gain control, symbol timing and carrier phase synchronisation, we demonstrate the processes required to ‘lock’ the receiver to the transmitted QPSK signal, and output the received data to the MATLAB command window.
Desktop QPSK: ASCII Message Receiver top
In this video we present the final stages of the simple QPSK Tx Rx stack, incorporating frame synchronisation and symbol phase ambiguity correction. With these in place, we are able to transmit ASCII text messages from one computer to another.
Desktop QPSK: Greyscale Image Receiver top
In this final QPSK video, we demonstrate how the QPSK Tx Rx pair developed to transmit and receive ASCII text messages can be re-purposed to transmit greyscale images by simply modifying the higher layers of the stack. Because we have stuck with the low data rate from the previous exercises, it takes some time to transmit complete images, so the end of this video has been sped up.
Desktop Data in FM: ASCII/ Audio Receiver top
In this video, we talk you through the full architecture of the Physical layer of the Data in FM PHY, that allows us to transmit digital information (in the form of ASCII text strings), and a music signal simultaneously with a $5 FM Transmitter. This exercise is a low cost alternative to the USRP QPSK ASCII Message Tx Rx pair, with the only difference being that the QPSK PHY has been replaced with the Data in FM PHY.
Desktop Data in FM: Image/ Audio Receiver top
In this final exercise video, we demonstrate how a $5 FM transmitter can be used to transmit digital information (in the form of greyscale images), and a music signal simultaneously. This transmit and receive pair once again make use of our Data in FM PHY, and are a low cost alternative to the USRP QPSK Greyscale Image Tx Rx pair.