Im trying to use GNUradio 3.8 with an sdr to pick up some wifi packets 2.4 and 5 GHz but im seeing a ton of dropped samples from my sdr. Im wondering if my dropped samples have to do with the sample rate. Ive seen online sdrs have a mixer that downconvert the frequency band to baseband and then its sampled. But i believe one cannot configure arbitrary sample rates, as the receiver expects a given number of samples per symbol. Is this correct. If im trying to sample 2.4Ghz and 5Ghz a/b/g/n how do i figure out my sample rate/dropped samples issue. Thanks
At the very least, you'll need a sampling rate that's high enough to capture the full bandwidth of your Wifi transmission. In a typical WiFi receiver, that puts the sample rate at exactly the OFDM width: 5, 10, 20 or 40 MHz, depending on your Wifi.
Your dropped samples simply happen because your computer isn't fast enough to keep up with that many samples per second. There's only two solutions to that:
- Get a faster computer
- Make your computer do less per sample.
Also note that the sustained write rates of permanent storage devices can be lower than your sample data rate, so even just writing to disk can be a fatal bottleneck.
Sadly, we don't know the processing you're currently doing, but maybe have a look at gr-ieee802-11, which is optimal enough that a modern midrange laptop can receive 20 MHz wide Wifi with it, continuously.