Standards-based Waveform Creation Software Allows for Fast, Accurate and Cost-effective Testing of Wireless Technologies
By Lynne Patterson, Anritsu Company

Designers and manufacturers of wireless handsets and systems are climbing a slippery slope. The continued evolution towards 4G network deployment by carriers is in its infancy, as technologies such as LTE, UMB and 802.16m WiMAX are expected to be initially implemented in 2010. While one eye is on these future technologies, the other eye must remain focused on existing technologies, such as 1xEV-DO, HSPA, GSM/EDGE, WiMAX and W-CDMA, which will remain viable for years to come.

Ensuring quality performance of products under these market conditions requires flexible test options. It is not cost-effective to have test instruments designed solely for one or two of these technologies. Rather, test solutions have to feature a design that will allow for cost-effective, simple, and accurate analysis that will help ensure performance and improve time to market. Anritsu Company has developed its IQproducer™ for many of its instruments, including the MG3700A Vector Signal Analyzer and MS69xA Signal Analyzers, to address this market need.

IQproducer is application software with a graphical user interface (GUI) for setting parameters and generating waveform patterns in compliance with appropriate standards for respective technologies. Developed to take advantage of the design of the MG3700A and MS269xA Signal Generator option, IQproducer can be used for:

• Parameter Editing – users can easily edit parameters matching each communication method.

• Simulation – it has a function for checking generated waveform patterns before transferring to CCDF and FFT graphs.

• Conversion – waveform patterns created by simulation tools or captured by the digitizing function of the MS269xA Series can be converted to compatible waveform files. Files converted in this manner can be used with either the MG3700A or the Signal Generator option in the MS269xA Series.

The MG3700A (Figure 1) features a 160-MHz high-speed ARB baseband generator, broadband vector modulation, and large-capacity ARB memory of up to 512 Msamples/channel to support the most popular digital modulation signals. Its built-in ARB generator allows it to easily output the required signals created by the waveform patterns created by IQproducer. The software’s GUI, which features familiar drop-down menus, makes it easy to select the appropriate waveform.

IQproducer waveforms can also be used with the Signal Generator option on the MS269xA Series (Figure 2). Unlike other instruments with a basic band limit of 3 GHz, the MS2690A/MS2691A/MS2692A signal analyzers use leading-edge architecture offering a basic band that goes to 6 GHz. They also have FFT analysis over a 125 MHz bandwidth and a digitizing function that accurately captures signal waveforms with no signal dropout. These advanced functions are ideal for measuring the next-generation communication systems being developed. Adding the Signal Generator option to any MS269xA analyzer creates a one-box test device with superior performance characteristics. IQproducer increases the power of this combination by providing a simple method for creating, modifying, and analyzing standards-based signals.

Easy to install and use, IQproducer allows a single instrument, such as the MG3700A or MS269xA, to conduct conformance measurements on various handsets and systems, saving money, space, and time. IQproducer is available for HSDPA/HSUPA, CDMA2000 1xEV-DO, W-CDMA, TDMA, Mobile WiMAX, and LTE. It can be installed directly on the MS269xA analyzers, eliminating the need for an external PC in the test setup, thereby further cutting costs and improving efficiency. For the MG3700A, IQproducer generates waveform pattern files on a PC, which can be easily transferred to the instrument using a LAN connection or a compact flash memory card.

Accurate LTE Testing
For LTE measurements, IQproducer can be used with the MG3700A and/or MS269xA to generate waveform patterns in compliance with the 3GPP LTE FDD specifications in the 3GPP TS36.211, TS36.212, and TS25.81 standards. Once created, the waveform pattern files are downloaded to the instrument’s hard drive.

In the case of the MG3700A, the files are loaded, selected, and outputted as a modulated LTE signal via the MG3700A’s Vector Signal Generator functionality. Measurements can then be made on common parameters, such as number of frames, bandwidth, cyclic prefix, and filter, as well as key LTE downlink and uplink parameters.

The MS269xA Series outputs the waveform patterns as RF signals from the analyzer’s optional signal generator. With this capability, RF receiver characteristics can be tested and transmitter and receiver evaluations can be performed. User-defined reference signals can be created and incorporated into the waveform files for transmission, as well as loaded into the MS269xA Series for quick and accurate analysis.

IQproducer works with the MG3700A and MS269xA in a similar fashion to create waveforms for other wireless technologies. Table 1 and 2 outline some of the parameters that can be varied by the user to create appropriate test waveforms.

Conclusion
The migration from 3G to 4G makes it difficult to cost-effectively test products and systems. Flexible test solutions that combine instruments with open designs and application-specific software are making it easier, faster, and more cost effective. By delivering these requirements without sacrificing accuracy, test manufacturers can create a measurement environment that will help in the deployment of 4G technologies, while also ensuring the performance of existing wireless networks.

ANRITSU
www.anritsu.com
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