Tektronix NetTek YBT250, User Manual

Page: 274 / 338

Appendix A: Specifications
A- 14
YBT250 Field Transmitter & Interference Tester User Manual
Table A- 2: Measurement characteristics (Cont.)
Measurement Description
GSM/EDGE Origin Offset Origin Offset is the ratio of unmodulated signal power to
modulated signal power. The unmodulated signal
component causes the signal constellation center to be
offset from the ideal location. The Origin Offset
measurement is made over one GSM or EDGE burst.
Units dB
Resolution 0.01 dB
Range --15 dB to --60 dB
GSM/EDGE Carrier to Interfer-
ence (C/I) Carrier to Interference (C/I) is the ratio of desired signal
(carrier) to undesired signal (interference). The C/I
measurement is derived from the EVM result and gives
an estimate of the power-based C/I value. The C/I
measurement is made over one GSM or EDGE burst.
Units dB
Resolution 0.01 dB
Range 0 dB to 50 dB
Reference Information:
C/I is derived from EVM using the following equation:
C/I = --20 * log10( EVM/100 )
GSM/EDGE RF Power vs Time Power vs Time displays the normalized signal envelope
power over one GSM or EDGE burst.
Units Time Axis:
Symbols
Microseconds
Resolution Time Axis:
1 symbol
1 microsecond
Time uncertainty
±
0.2 symbol
±
0.8 microsecond
Reference Information:
Burst to mask alignment is derived from the location of
the Training Sequence in the useful part of the burst.