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Sylvain Munaut 246tnt at gmail.comHi, > I’m an engineer from Spain and I’m interested in a GSM receiver because I > would like to study the internal signals for a research project. In > particular, I’m interested in the analysis of the IF signal, but, as > Alexander told me, the LMS6002D uses zero-IF architecture, so there is no > real "IF" signal, there is only baseband signal. Well, they also have a optional GSM front end board that has an IF. However it has a very narrow IF filter since the goal was to about in-band interference from neighbour channels ... > I guess I could also use > this signal for my purposes, but only if all 124 GSM channels can be found > at that point. I’m not sure if this is possible, since there is a low-pass > filter before. Does anybody know if I can extract that information, that is, > the analogic 124 channels after the RF mixer? The filters can be set to 28 MHz wide and the LMS has analog I/Q debug outputs, so yes you could get the analog out. But it's I/Q not a single signals so you'll need two fast ADC to get it digitized. OTOH why wouldn't you just use the ADC in the LMS ? They're clocked at 26 Mhz (or could even be fed higher frequency) and so you should be able to get the whole 25 MHz of P-GSM band. Cheers, Sylvain