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Agilent Technologies has added cdma2000 perceptual evaluation of speech quality (PESQ) measurement functionality to its 8960 wireless communications test set (see the figure). With this capability, the company says, wireless engineers can enhance the end-user experience by providing an objective measurement of audio quality in digitally vocoded voice.

Designers now can use the Agilent 8960 wireless communications test set for cdma2000 PESQ measurements.

Many new implementations of vocoder algorithms are designed to provide higher-quality voice at lower data rates. Yet the sensitivity and transmitter quality of a mobile handset affects vocoder performance, determining the voice quality heard by the user. Agilent’s implementation of the PESQ measurement predicts vocoder speech quality using the algorithm recommended by the ITU-T P.862 standard.

To enable an objective comparison of results, downlink and uplink voice quality are rated on a scale of one to five. This implementation is self-contained within the 8960, which doesn’t need an external audio analyzer. Agilent says that this will simplify test procedures and reduce the total number of test stations in characterizing voice quality in handsets.

Using any of the three real-time vocoders built into Agilent’s 8960, the PESQ measurement applies a male or female sample voice to a phone and compares the resulting voice signal to the reference. Audio input and output to and from the phone is routed through ports on the front panel of the 8960.

According to Agilent, the 8960 is the only cellular network emulator with the power and performance to test at all phases of a mobile device’s lifecycle: design, integration, validation, conformance test, manufacturing, and repair. The company also says that its capabilities improve test efficiency, enhance test management, and simplify support of test equipment.  

The Agilent cdma2000 PESQ capability is available now as part of the Agilent E19262B cdma test application or the E6702C cdma2000 lab application along with the E1999A-301 feature license, which costs $4000.