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General Description
R&S
®
CMW-B400B/-B405A
10
User Manual 1176.8116.02 ─ 04
3 General Description
The "Audio Analyzer/Generator" option enhances the R&S
CMW for audio tests. A sin-
gle option (R&S CMW-B400B or R&S CMW-U400) provides an audio board, two ana-
log and two digital audio generator instances, two analog and two digital audio mea-
surement instances, four analog AF connectors at the front panel and two digital
SPDIF connectors at the rear panel.
You can use all generator and measurement instances in parallel. So you can gener-
ate and measure two analog mono audio test signals and two digital mono audio test
signals in parallel. You can also generate and measure a stereo signal by combining
two generator and measurement instances.
The tests cover the following audio signal properties:
●
Characteristics of a single tone signal, for example Total Harmonic Distortion
(THD), Signal to Noise and Distortion ratio (SINAD) and Signal to Noise Ratio
(SNR).
●
Audio levels of up to 20 single tones at configurable frequencies and levels, com-
bined to a multitone signal.
●
Audio level vs. frequency for a noise signal, consisting of several thousand single
tones. The noise signal has a very low crest factor. It is ideal to analyze the fre-
quency response of a DUT over the entire audio frequency range, with a single
measurement.
Two audio analyzer and generator options are available. They provide the same test
functionality. Which option is required, depends on your instrument:
●
Option R&S CMW-B400B "Audio Analyzer/Generator" is compatible to R&S
CMW
delivered after September 2011. It is also compatible to R&S
CMW delivered
before September 2011, that have been upgraded with R&S CMW-U5024.
●
Option R&S CMW-U400 "Audio Analyzer/Generator" is compatible to R&S
CMW
delivered before September 2011, that have not been upgraded with R&S CMW-
U5024.
Optional speech codec
Optionally, the audio board can be enhanced with a speech codec (R&S CMW-
B405A).
A speech codec provides an interface to the signaling units of the R&S
CMW. It
decodes the signal delivered by a controlling application or encodes an audio signal
and delivers it to the controlling application.
Thus the speech codec allows to feed an audio signal into an established RF connec-
tion to the DUT or to extract an audio signal from the RF connection. The controlling
application can be a signaling application, the IMS server of the DAU (for VoLTE) or a
protocol test application.
The audio signal can be generated and analyzed internally using the digital audio gen-
erator and measurement. This allows for example microphone- and speaker tests for a
mobile phone.
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