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Is it possible to capture the raw signal from a WiFi card in the same way you can capture the signal from a sound card? (I already found code for working with a sound card and for drawing spectrograms) I'm wondering because it would make a cool radio-type project. I'd prefer a solution that integerates well with .net (VB or C#).

My basic goal is to capture the ambient radio waves and build a primative "telescope" of sorts. Using the built in computer hardware is just the easiest way to accomplish this. If you have any other suggestions about how to accomplish this goal in a different way please post it as an answer also.

Thanks.

John
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  • Do you plan to use a high-gain directional antenna too? If not, "telescope" is a poor analogy... – Igby Largeman May 09 '12 at 00:26
  • Wifi operates in the 2.4 GHz to 5 GHz RF bands. (Do a search for 802.11 for more info). There is no direct software interface to the Wifi signal. There is a Wifi modem that does the mod and demod for the WiFi signal. You might be able to interface with the modem. – Jim Merkel May 09 '12 at 03:51

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Look up "Software Defined Radio". They are usually either radio electronic kits or fairly expensive hardware. You will still need an antenna.

hotpaw2
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  • GNU Radio is a good place to start: http://gnuradio.org/redmine/projects/gnuradio/wiki – Paul R May 09 '12 at 06:50
  • With GNU Radio you will need RF front end hardware to filter and digitize the signal. Considering the bandwidth of the WiFi signal of 100 to 200 MHz, that hardware won't be cheap. Furthermore I doubt that a run-of-the mill processor will be able to handle the required processing for this bandwidth. (Consider processing an input sample rate of 200 to 400 MSPS) You probably need special purpose DSP hardware (FPGA or ASIC) to do front end processing. To answer the OPs original question -- this is quite a bit more complex than processing an audio signal at say 40000 samples per second. – Jim Merkel May 09 '12 at 19:33