RADIO COMMUNICA TIONS TEST INSTRUMENTS
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GPIB
The MG3670B/C, MG3671A/B is a digital modulation signal generator equipped with a high-performance quadrature modulator. It outputs the signals needed to develop, test and evaluate digital mobile
communications equipment and related devices with expansion units.
The MG3670B/C, MG3671A/B covers the frequency range from 300
kHz to 2.25 GHz (MG3670B/C)/300 kHz to 2.75 GHz (MG3671A/B),
and provides a stable and precise output as well as spectrum purity
up to a maximum output of +13 dBm, even with modulation. In addition to testing receiver sensitivity and excess input, it can be used for
testing IF stage performance and for evaluating device quality. A
CMOS-level mode is provided for I/Q signal input. The input frequency band covers the CDMA spread spectrum band, expanding
the range of applications.
The MG3670C and MG3671B are expanded applications by rear
panel extension connectors to use for auxiliary signal output function
special to communication system. MG3670B/C and MG3671A/B can
be used in combination with up to seven modulation units, and a
burst function unit, simultaneously.
The MG0301C/0302A/0305A/0307A/0311A modulation units have a
continuous data generator capable of generating arbitrarily-programmable data signals and ITU-T specification PN9/15 stage PRBS signals, as well as band-limiting filters, and they can output I/Q baseband signals.
The MG0303A Burst Function Unit uses the frame and slot configuration stipulated by various communication systems, and has a modulation pattern generator function and a function for ramp control of
carrier burst signals. It can also handle data editing and scrambling.
The MG0310A Modulation Unit generates SS + QPSK/OQPSK modulated (1.2288 Mcps) I/Q baseband signals, supporting the CDMA
system (TIA/EIA/IS-95) used in US Digital Cellular Systems and the
US Personal Communications Service (PCS).
Anritsu-developed DSP and ASIC technology is used in the MG0310A
to achieve superior waveform quality factor (ρ) and spurious emission characteristics. Channel multiplexed signals are supported for
both forward and reverse links.
With two MG0310A units mounted in the MG3670C/3671B, all the
test signals required to conform to TIA/EIA/IS-95, -97 & -98 can be
generated. Simultaneous outputs from the rear extension connectors
using long & short codes, etc., support a wide range of applications
including RF related tests, IF stage performance tests, and device
and module quality evaluation. (Option 25 is required to install the
MG0310A in the MG3670B/3671A. The auxiliary signal output function is not installed, so long/short codes cannot be output.)
The MG0312A QPSK Modulation Unit generates QPSK/OQPSK
modulated I/O baseband signals at 8 high speed bit rates between
500 kbps and 2.4576 Mbps. Built in modulation data includes NP7/
PN9/PN15/PN23 pseudorandom patterns. Use over a wide range is
supported by multiple baseband filters, and the Phase Encoding
function which allows modulation data to be voluntarily phase mapped
onto a constellation.
At the 2.4576 Mbps bit rate, the evaluation of transmission section
devices and modules can be performed such as RF power amplifier
for CDMA mobile station.
DIGIT AL MODULATION SIGNAL GENERATOR
MG3670B/C, MG3671A/B
300 kHz to 2.25/2.75 GHz
Communication
systems
Units
PHS, PDC, PDC_H, MG0301C
NADC, TFTS π/4 DQPSK Modulation Unit
GSM, PCN, CT2
MG0302A
GMSK Modulation Unit
DECT
MG0305A MG0303B
GFSK Modulation Unit Burst Function Unit
PACS, WCPE, PHS
MG0307A
π/4 DQPSK Modulation Unit
TETRA
MG0311A
π/4 DQPSK Modulation Unit
IS-95
MG0310A CDMA Modulation Unit
MG0312A QPSK Modulation Unit
Features
•Compatible with communication system measurement signals of
Japan, North America and Europe
•High modulation accuracy (≤1.8% rms vector error)
•
Outputs modulation signals suited to each communication systems
•
Internal pattern generator with data-editing and scrambling functions
•Outputs IS-95 channel multiplex signal
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RADIO COMMUNICA TIONS TEST INSTRUMENTS
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Basic performance
•I/Q signal I/O over broad frequency range
A quadrature modulator is built in, and external I/Q signals can be input to enable use with a variety of digital modulation modes, including QPSK, 8PSK and M16QAM. The modulation band for I/Q input
signals is broad, covering the CDMA spread spectrum bandwidth.
Further, by adding an expansion unit, I/Q signal output can be obtained from the internal data generator. Either 50 Ω or CMOS-level
compatibility can be selected for I/Q signals. Functions for adjusting
the level balance, offset and phase are also provided for greater utility in evaluating modulators/demodulators and other devices.
Output level frequency characteristics
(50 Ω/0.5 Vrms mode)
30 k 100 k 300 k 1 M 10 M3 M
0
–1
–2
–3
Level (dB)
I/Q signal input frequency (Hz)
Frequency response for I/Q external modulation (typical values)
•Excellent spectral purity
The SSB phase noise characteristic is an excellent –120 dBc/Hz or
less (100 kHz offset). The adjacent channel power characteristic excels as the interference signal source during modulation.
SSB phase noise at 1.9 GHz
•Large output level
Through use of new AGC circuitry, the MG3670B/C, MG3671A/B
produces a highly precise output at levels down to –143 dBm with
stable frequency characteristics, not only for output of unmodulated
signals, but also with π/4 DQPSK modulation accompanied by amplitude fluctuations, and when outputting burst signals. The MG3670B/C,
MG3671A/B can generate a high output level of up to +13 dBm over
a broad range of frequencies, so amplifiers are not needed even
when testing receivers for excess input, and in testing other devices.
Output level accuracy at 1.9 GHz
•High modulation accuracy
A vector error of less than 1.8%rms is assured for output levels up to
+5 dBm over the entire operating frequency range. This high modulation accuracy is also achieved when the expansion units are used.
Even when the MG0301C and MG0303B units are installed and π/4
DQPSK modulation burst signals are generated, the vector error is
less than 1.8%rms. The MG3670B/C, MG3671A/B enables measurement and quality evaluation of receivers and other devices with more
than adequate precision.
Functions and performances with expansion unit
• Frame structure and data
TDMA
The MG0303B incorporates TDMA frames for various kinds of communication systems, as well as modulation patterns for each time
slot.
Modulation patterns for device evaluation and for up/down communication channels are provided, and are output at the timing required
by the system. Hence the MG3670B/C, MG3671A/B can generate the
burst signals needed to measure various digital communication systems.
Time slots specified for different communication systems can be selected freely. There is considerable freedom in choosing the modulation pattern within slots; either a PN9 or PN15 TCH segment can be
chosen, and part of the data outside the TCH segment can be edited.
The pattern memory function can be used to store and recall patterns.
A data scrambling function is provided as standard, and any initial
code can be set permitting more sophisticated evaluations and diagnostics using the MG3670B/C, MG3671A/B as a supposed base station and mobile equipment.
The internal modulation pattern can also be driven by an external
clock, so margin tests can be conducted by varying the clock pulse.
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Pattern edit display
CDMA
MG0310A has various TIA/EIA/IS-95 frame format and encoder
functions built-in for each channel types. For example, frame format
of signalling, communication and Multiplex Option 1 are provided to
support Rate Set 1 (1200 ... 9600 bps) and Rate Set 2 (1800 ...
14400 bps) for the Traffic Channel. In combination with the Burst
Randomizer function, this allows system support at all rates, even for
reverse links. For internal data you can select either a PN7, 9 or 15
pseudo-random pattern, or a user settable 16-bit data repeating pattern, all fully editable. Operation can be from internal RAM user-definable sequence data or from external serial data.
Pattern setting display
• Excellent leakage power characteristics during carrier-off
The rising and falling edges of burst signals have a gentle waveform
with a duration equivalent to two symbols, and the leakage power
during carrier-off characteristics are excellent.
PHS
Slot rise time waveform
• Superior spurious emission characteristics
Spurious emissions are guaranteed to be lower than –60 dBc (±900
kHz detuning, 30 kHz bandwidth) and –70 dBc (± 1.98 MHz detuning,
30 kHz bandwidth) with MG0310A installed in the MG3670C/3671B
mainframe (for output level: 0dBm, baseband filter: SPEC 2). Using
this baseband filter gives a waveform quality factor (ρ) of 0.999 or
better. This filter conforms to IS-95, providing 3-step switching.
Selecting the best step for each evaluation item gives even higher
performance. This excellent basic performance in a standard digital
modulation signal generator makes it the ideal choice for the development and manufacture of digital mobile wireless equipment and
related devices/modules.
Modulation spectrum
(with MG0310A installed in the MG3670C/3671B)
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