Implementing wireless protocol parametric tests using the off-the-shelf commercial products to lower the cost and reduce the test time of mobile phones.
The Solution:
Building an automated PXI-based mobile phone parametric test system using National Instruments PXI-5660 RF signal analyzer with the newly developed Wireless Test Toolset for LabVIEW to replace expensive and inflexible traditional box instruments.
Delivering a Fast, Flexible Test System
The cost of test equipment is a major concern of OEM and EMS phone manufacturers. Testing a mobile phone requires approximately one to three minutes and an estimated $1 per phone. This often hinders the enhancement of overall mobile phone output. VI Services, a National Instruments Alliance Member based in mainland China, has developed a low-cost, efficient mobile phone test system for SCDMA-based 3G handsets using LabVIEW and related RF hardware. Using virtual instrumentation technology and some proprietary techniques, this system has significant advantages over traditional box instruments. Because the customer has full control of the test plan, he or she can chose different test configurations. A parallel test in one custom application improved the test speed by four fold. In addition to the specific parametric tests required by the SCMA protocol, the customer can add more tests using PXI or PCI extensions, such as the multimedia test, voice quality test, LCD test, and the key stroke tests. These types of expansion are not possible with box instruments. Because PXI and PCI are general-purpose test platforms, mobile phone manufacturers can reuse the same equipment to a large degree when testing needs change. This is especially important for an OEM and EMS manufacturers.
The current offerings can perform parametric tests for protocols, including GSM, CDMA, SCDMA and TD-SCDMA. The GSM is the most widely used mobile communications standards in the world and is being used in China, Europe and many other countries. CDMA is being used in US, Japan, and Korea. A CDMA network is also being established in China. SCDMA and TD-SCDMA are locally developed communications standards in China for wide application use. Because a major part of the protocol tests involve the parametric protocol implementation, it is expected the current system can be expanded easily to CDMA 2000 and W-CDMA.
Decreasing Test Time and Minimizing Investment with PXI
We developed a mobile phone test system using the NI PXI-5660 RF signal analyzer and an external RF signal generator solution. The PXI-5660 features a wide real-time bandwidth, highly stable time-base, and vector measurement capabilities that makes it ideal for RF component and commercial electronic tests. This low-cost platform provides one of the most optimized data transfer architectures available – ideal for decreasing test times and minimizing investments. PXI products make it easy to address non-RF testing requirements, including electrical and audio performance. We also have developed a PCI and MXI-3-based system that uses the identical software while further reducing the cost of the test system.
Designing a Powerful Protocol Test Instrument with LabVIEW
The heart of the mobile phone test system is The Wireless Test Toolset software, which we developed almost entirely in LabVIEW. This toolset is a highly optimized platform that turns an RF digitizer into a powerful protocol test instrument. It also differentiates NI RF hardware from other RF instruments. Using the high-level VI functions in this toolset, customers can access the protocol test code that was previously embedded in proprietary box instrument and not accessible by the end user. With these functions, customers can construct highly efficient, flexible manufacturing test systems for mobile phone handsets.
Because The Wireless Test Toolset software is based on the LabVIEW graphical programming environment, customers can seamlessly integrate it into National Instruments off-the-shelf TestStand test executive software, which further improves the test efficiency for manufacturing tests.
Pioneering the SCMA Communications Standard
Xin Wei Co. LTD (www.xinwei.com.cn), is a local Chinese telecommunications company. Together with Da Tang and other partners, Xin Wei pioneered and codeveloped the SCDMA standard. The SCDMA protocol is one of the foundations of TD-SCDMA, the 3G protocol developed in China. Xin Wei’s SCDMA operates on 1.8 GHz bandwidth. It offers a low-cost wireless access and message services to small cities. An ambitious plan is under way to populate SCDMA network to major cities. Working with Xin Wei Co. Ltd, VI Services successfully developed a SCDMA mobile phone online test station using the PXI-5660 RF signal analyzer, LabVIEW, and the Wireless Test Toolset. For each mobile phone product line, we replace two box instrument test systems based on GPIB instrumentation with one new test station. Simultaneously, the test throughput has almost doubled on each product line. This results to almost four times of performance improvement. The system has been used for several months at Xin Wei’s manufacturing facility.
Lowering Costs and Improving Efficiency with PXI
A PXI-based wireless testing system can provide customers with many benefits, including:
Lowering the cost of manufacturing every mobile phone
Increasing efficiency in manufacturing
Minimizing test space
The LabVIEW-based Wireless Test Toolset offers high-level functions and examples, so customers can construct a flexible and scalable solution. Customers can use the turn-key test system or construct a fully customized test system.
