<to maintain a lead ahead of Motorola>
Hmm, do you always tend to get things absolutely the wrong way.
Motorola was a very "creative" part in building the GSM standard, and was the "leader" for a long time.
What europe didn't do was to build a DAMPS ontop of AMPS, same narrow 30kHz bandwidth, huge debate on
narrow 30kHz and broadband 200kHz, multipath fading,etc at that time.
That is, no digital "DNMT" based on analog NMT, NMT left alone as it was ( which is/was very similar to AMPS, but somewhat improved).
GSM was brand new technology, brand new spectra, even a place for SMS messages. clearly above the limit
of the DSPs of that time, when 10mHz and 10MIPS was a dream, vocoders and all.
And luckily constant envelope modulation, no linear PA amplifiers needed, like in the US DAMPS,
restricted by having to work on the same 30kHz bandwith as AMPS. (thus the small size, long
talk and especially stand-by times)
If you want to do some bashing, you should bash GSM-EDGE for finally being forced to admit to 8-PSK
and "higher modulations", what DAMPS did already ten years ago.
Same as CDMA, must have those powerhungry,expensive,wasteful linear RF thingies.
Ilmarinen
Btw, the FM modulation used in AMPS/NMT is also constant envelope, but as everyone knows, wastes battery just by beeing analog |
