Have been studying cell phone signals for quite a while using the dongle SDR and the NutsAboutNets spectrum analyzer, have gotten to the point where I can tell when the driver of a car passing by our street is on the phone. But here is a picture of what the SDR dongle captured when I dialed my LG phone. Cell uplink signals kind of look like long wideband horizontal bars. The phone will display different signal patterns on the waterfall when turned on, off, when dialing, and talking. Of course there are different cell phone bands and cell phones so this image may not be typical, but having studied the waterfall images of cars passing by, they pretty much look like the one below.
Sponge
Sponge
