I'm interested in Software Defined Radio. I have basically no experience in any of the electrical engineering or math topics involved, but I'm reading...
Rather than trying to deal with the hardware aspect of the antenna and the ADC, I imagine it'd be fun enough (and cheaper) to play with some pre-recorded (or even live!) sample streams of the AM band.
From what I've learned so far, it seems to me that the AM format would be the easiest to decipher - a narrow bandpass/windowing function over the entire spectrum to get any target frequency, then a short running average transform(?) to get another sample/sample amplitude to get the audio signal.
For the full North American AM band, seems to me that the uncompressed stream would be:
1606.5 kilobytes x 2 (twice the frequency for samples) x 2 (16-bit samples) = 6.28 megabytes per second
It's probably clear that I'd be wasting my money on the hardware at this point... Any sources of AM band out there? Or other better ideas for hands-on learning?
You should talk to the GNU Radio folks, or at least look at their code. They're doing software radio development and must have samples for doing unit testing.
来源：https://stackoverflow.com/questions/3119877/software-defined-radio-am-band-sample-source