Part 1

Visit the link How to capture raw I/Q data from a RTL-SDR dongle and FM demodulate with MATLAB .

Download the file: FMCapture1.dat (there is a link to this file about a third of the way down on the webpage above). This file contains ten seconds of recorded I/Q data (this is described in detail in the webpage above).

Using the techniques presented in the webpage above, import the data into MATLAB, FM demodulate, and listen to each of the six radio stations contained within the bandwidth of the captured signal (98.7 FM, 99.5 FM, 99.9 FM, 100.3 FM, 100.7 FM, and 101.1 FM).

What to turn in for Part 1:

Turn in a little description of what you hear in each of the six radio stations. Note: some stations are very weak, and you may hear a low-volume noisy signal.

Part 2

I used a $20 NooElec NESDR Mini SDR USB dongle to capture the I/Q data for Part 1 above. This receiver is based on two IC's: RTL2832 and R820T. For Part 2 of this assignment, research these chips and draw a block diagram of the NooElec NESDR Mini SDR USB dongle. Your block diagram should display the RF subsystems you learned in class like amplifiers, local oscillators, mixers, antennas, etc. While I prefer you draw your block diagram drawn using a software program, you are free to hand-draw your block diagram as long as it's neat and easy to read.

Your block diagram should show all the major processing steps that convert the incoming RF signals to baseband I/Q signals. Display useful information and receiver system parameters on your block diagram such as IF frequencies, filter bandwidths, sampling rates, ADCs, etc. Denote what signal processing functions are implemented in hardware, and what functions are implemented in software.

What to turn in for Part 2:

Turn in your block diagram. Your block diagram will be graded on its presentation, clarity, accuracy, and comprehensiveness.

Some useful links:

1. Software Defined Radio and the RTL-SDR USB Dongle Lab (University of Colorado - Colorado Springs): Very useful! Check this out first.
2. R820T datasheet
3. Specific information on the RTL2832U
4. Great all-around information on RTL-SDR radios
5. Realtek's RTL2832U product webpage

A note on the R820T:

Information regarding inner workings of the R820T is very scant. The data sheet for the R820T mentions a "tracking filter". We can therefore assume that the R820T achieves image rejection via a tracking filter and an image-reject mixer similar in principle to other silicon-based TV tuners like the Maximum MAX3544 and the NXP TDA18272HN. A related patent for such system is: TVRO receiver system with tracking filter for rejection of image frequencies.