It is often quoted that "3g uses more power than 2g on voice calls" or other similar things, but it seems from a theory perspective that transmitting low bandwidth voice data with a high bandwidth protocol like UMTS, HSDPA etc. with more spectrally efficient modulation should use less energy than transmitting the same data over an older standard network like GSM which has less spectrally efficient coding, lower data rates, and longer timeslices.
Rumour is that the majority of the power in new protocols is not used in the actual emitted radio waves, but instead in the electronics that process, amplify and modulate the signal. Is this the case? Are there any public studies/numbers to back this up?
Thanks in advance, Oliver