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Gsmk modulation, Edge/gsm, 3π /8 8psk modulation gsm – Atec Agilent-E4406A User Manual

Page 15

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15

EDGE/GSM

(Option E4406A-202)

3

π

/8 8PSK Modulation

GSM

(Option E4406A-BAH)

GSMK Modulation

Power versus time measurement

Power versus time measures the average power during the
“useful part” of the EDGE or GSM burst and verifies that
the power ramp is within the EDGE or GSM mask. The
specified EDGE or GSM masks for both base transceiver
stations and mobile stations are provided. Power versus
time also lets you view the rise, fall, and “useful part” of
the burst. The timings are referenced to the transmitter
from bit 13 to 14 of the training sequence (midamble).

Power vs. time and EDGE power vs. time

GMSK modulation (GSM)
3

π

/8 shifted 8PSK modulation (EDGE)

Measures mean transmitted RF carrier power during the
useful part of the burst (GSM method) and the power vs.
time ramping. 510 kHz RBW

Minimum carrier power

–30 dBm (nominal)

at RF input for GSM
and EDGE

Absolute power accuracy for in-band signal
(excluding mismatch error)

18 to 30 °C;

–0.11 ± 0.60 dB
(–0.11 ± 0.40 dB, typical)

0 to 55 °C;

–0.11 ± 0.90 dB

Power ramp relative

Referenced to mean

accuracy

transmitted power

RF input range = Auto

±0.26 dB

+6 dB to noise

Mixer level

-12 dBm

±0.26 dB

+6 dB to noise

Measurement floor

–81 dBm + input attenuation
(nominal)

Time resolution

200 ns

Burst to mask uncertainty ±0.2 bit (approx ±0.7 µs)

EDGE EVM measurement

The EDGE EVM measurement measures the modulation
quality of the 3

π

/8 8PSK modulated signal providing you

with IQ constellation diagram, error vector magnitude
(EVM) in RMS and peak, 95 percentile, and I/Q origin offset.

EDGE (EVM)

3

π

/8 shifted 8PSK modulation

Error Vector Magnitude

Specifications based on 3GPP
essential conformance
requirements, and are based on
200 bursts

Carrier power range

–45 dBm (nominal)

at RF input

EVM

Range

0 to 25% (nominal)

Floor (RMS)

0.5%, (0.3%, typical)

Accuracy (RMS)

±0.5% (Power range at
RF input from +27 to –12 dBm,
EVM range 1% to 11%)

Frequency error

±1 Hz + (transmitter frequency
x frequency reference accuracy)

I/Q origin offset range

–20 to –45 dBc

Output RF spectrum measurement

The output RF spectrum measurements determine the
spectral energy emitted into the adjacent channels. The
measurements are divided into two types: spectrum due to
3

π

/8 8PSK or GMSK modulation and noise, and spectrum

due to switching transients (burst ramping). A single offset
can be examined with a corresponding trace, or up to 15
offsets can be measured with a tabular data display.

Minimum carrier power

-15 dBm (nominal)

at RF input

ORFS relative RF power uncertainty

Due to modulation

Offsets

1.2 MHz

±0.26 dB

Offsets

1.8 MHz

±0.36 dB

Due to switching

±0.27 dB (nominal)

ORFS absolute RF power ±0.60 dB (±0.40 dB, typical)
accuracy 20 to 30 °C

Dynamic range

5-pole sync-tuned filters

Spectrum due

Methods: direct time and FFT

to modulation

Offset frequency

GSM

EDGE

100 kHz

67.7 dB

67.7 dB

200 kHz

73.3 dB

73.3 dB

250 kHz

76.3 dB

76.3 dB

400 kHz

78.4 dB

77.9 dB

600 kHz

81.1 dB

80.2 dB

1.2 MHz

85.0 dB

83.3 dB

1.8 MHz

90.3 dB

82.4 dB

6.0 MHz

94.0 dB

85.3 dB

Spectrum due to switching

Offset frequency

400 kHz

68.7 dB (100%)

71.2 dB (95%)

600 kHz

71.0 dB (100%)

73.1 dB (95%)

1.2 MHz

74.1 dB (100%)

77.0 dB (95%)

1.8 MHz

78.4 dB (100%)

80.4 dB (95%)