Over-the-Air testing is vital if MIMO is to deliver good QoE – the smaller they get, the more gets packed into them…: Page 4 of 4

November 21, 2016 //By David Garrison, Spirent, Senior Director Wireless
Mobile devices and networks are growing ever more complex, not only in terms of features but also in the underlying technologies needed to support those features – technologies such as MIMO (Multi-Input Multi-Output) that require each tiny handset to contain not one but multiple radio antennas.

The Authorisation Process

So far, CTIA has published the Laboratory Assessment and Validation Requirements Document V1.1, which defines authorisation steps for system vendors and test labs and provides a template for reporting measurement uncertainty results.

The next step is to authorise the test system providers. This requires the on-site participation of a Subject Matter Expert (SME) and documents confirming compliance, including: data for MIMO OTA system validation results, a system configuration description, and example test data. System providers must also show baseline parameter file setups that have been verified for test plan compliance. When these steps are complete, validated configurations for hardware and software can be published as “authorised by the CTIA”.

Each test lab must also be authorised. Labs must first be accredited to ISO 17025 and have been previously authorised by the CTIA for SISO OTA testing using the same chamber. Labs must submit work instructions, test setup information for previously authorised equipment (identified above), sample test reports, and a measurement uncertainty test report for SME review. Once approved, the lab becomes a CTIA Authorized Test Lab (CATL) for MIMO OTA.

Once a critical mass of CATLs has been established, V1.0 will become mandatory for CTIA and PTCRB certification.

 

Conclusion

Examining MIMO antenna performance in realistic propagation environments gives an accurate view of the user experience and helps operators ensure good QoE. V1.0 of the CTIA MIMO OTA Test Plan defines standards for MIMO OTA testing, with upcoming releases already in the works.

Spatial channel emulation is an essential part of MIMO OTA testing and, as wireless networks advance toward 5G, the demands of device testing will become increasingly complex, requiring future-proof test solutions capable of scaling to support ever-higher channel density applications. The good news is that suitable robust channel emulation solutions are already available. These already support the CTIA MIMO OTA Test Plan v1.0 and they are being continually developed to meet the most stringent conditions of future CTIA test plan versions.

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