Software Eases LTE-Advanced Testing

May 18, 2011
These signal-generation and signal-analysis software tools work with high-performance hardware instruments to perform a wide range of physical-layer measurements on LTE-Advanced components.

Cellular technologies continue to be pushed for faster video service and higher data rates. And if newer fourth-generation (4G) technologies like WiMAX and Long Term Evolution (LTE) aren't enough, we now have LTE-Advancedwith more than three times the peak data downlink capacity as standard LTE. Of course, as devices are developed for this latest technology, they must be tested. Agilent Technologies, a company well known for its hardware solutions, is ready to adapt those solutions for LTE-Advanced testing with their Signal Studio signal generation software and 89600B vector signal analyzer (VSA) software.

The software is designed to work with the firm's advanced test instruments, such as the MXG vector signal generators (VSGs) with Signal Studio and PXA or MXA signal analyzers with the 89600B VSA software. For those tight on space, the company offers a single-box solution, the PXT E6621A LTE Wireless Communications test set. the PXT features integral signal generator and analyzer, in versions from 500 MHz to 3 GHz and to 6 GHz.

The Third Generation Partnership Program's (3GPP) latest effort at enhancing its LTE radio standard, LTE-advanced, is specified as part of the 3GPP release 10 specifications. it supports peak downlink data rate of 1 Gb/s and peak uplink rate of 500 Mb/s. it uses as much as 100 MHz by aggregating as many as five component carriers, each 20 MHz wide.

Signal Studio supports the generation of in-phase/quadrature (I/Q) bandwidths to 100 MHz with MXG VSGs. It supports frequency-division-duplex (FDD) and time-division-duplex (TDD) formats per 3GPP Release 10, and can generate component carriers (CCs) contiguously and noncontiguously (Fig. 1) to emulate different signals in an LTE-Advanced system. The clear benefit of this is the capability to evaluate a device under test (DUT), such as an integrated-circuit (IC) transceiver or amplifier, under challenging conditions, as might be faced with "real-world" LTE-Advanced signals.

This latest version of Signal Studio creates creates burst-type signals used in LTE and LTE-Advanced systems and assists in comprehensive physical layer (PHY) testing on a DUT, including for peak-to-average power ratio (PAR) and complementary cumulative density function (CCDF) measurements on uplink signals.

The 89600B VSA software (Fig. 2) mirrors signal studio software, but on the analysis side and with appropriate signal analyzer, such as an MXA or PXA. It works with FDD and TDD signals per 3GPP Release 10 with support for contiguous and noncontiguous CCs. The software coordinates to 140 MHz bandwidth with a PXA, and performs PHY testing, including CCDF and error-vector-magnitude (EVM) measurements.

The above software tools enable complex PHY testing of LTE-Advanced DUTS, including components for user equipment (UE) and evolved NodeB (eNB) base station equipment. The software can orchestrate simultaneous analysis on physical uplink control channel (PUCCH) and physical uplink shared channel (PUSCH) signals and analyze in-channel and adjacent-channel spurious from combined PUCCH and PUSCH transmissions.