GSM 测试技术培训.pdf
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GSM
Agenda
Share
Me
GSM
Separate Bands for Uplink and Downlink
TDMA and FDMA Multiplex
124 Frequency Channels (ARFCN) for GSM900
DL frequency = UL frequency + 45 MHz for
GSM900
200kHz Channels
8 Mobiles share ARFCN by TDMA
0.3 GMSK Modulation
270.833 kbits/sec. rate
Time
7
Amplitude 6
5
4 Timeslot #
3
2
1
0 Frequency
1 2 3 4 5 6
ARFCN #
Time
Overshoot
Amplitude
Lobes due to
modulation
Raised lobes due
to ramp up
Frequency
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