LTE-Advanced Uplink, 4x4 MIMO signal generation

March 26, 2014 // By Graham Prophet
Test solutions for the developing LTE-A mobile radio standard continue to come into place with Agilent Technologies’ assertion that it has an industry first with its LTE-A uplink 4x4 MIMO signal generation solution.

Designed to enable R&D engineers to verify FDD and TDD LTE-A Evolved Node B receivers, the package comprises N7624B/25B Signal Studio for LTE/LTE-Advanced FDD/TDD software with newly added support for UL 4x4 MIMO.

LTE-A is a leading fourth-generation wireless communications technology defined in Release 10, and all follow-on releases, of the 3GPP LTE standard. In Release 10, the eNB is required to support up to 8x8 MIMO in the downlink, while user equipment is required to support up to 4x4 MIMO in UL. Thanks to its recent UL 4x4 MIMO enhancement, Signal Studio is well-equipped to meet this requirement. Support for DL 8x8 MIMO was introduced last year.

In any MIMO system, ensuring the receiver correctly decodes the MIMO signal is paramount. Signal Studio with UL 4x4 MIMO support allows engineers to quickly generate a simulated 4x4 MIMO signal and download waveforms into multiple signal generators (e.g., Agilent MXG) or a baseband generator and channel emulator (e.g., Agilent PXB) for use during eNB receiver test. This capability is ideal for R&D engineers working in LTE-A early engagement, where access to real UE is generally not available. With the enhanced Signal Studio for LTE/LTE-A solution, engineers not only have a good replacement for UE at the early stage of the LTE-A standard, but also can more deeply evaluate their receivers.

DPD and envelope tracking test

Digital pre-distortion is a new capability being added to the LTE/LTE-A Signal Studio software. Also new is real-time LTE signal generation support for the Test Case Manager software, which works with Signal Studio. The DPD capability works with Signal Studio's envelope tracking function to help developers test ET power amplifiers. Using the capability, developers can apply DPD to their RF and ET signals before they are fed into an ET PA or power supply.

With support for real-time LTE signal generation now available in Test Case Manager, engineers working on LTE base stations can better handle