Radio head testing

Rohde & Schwarz has demonstrated the latest equipment development for testing LTE/WiMAX remote radio heads that communicate via the digital interface protocol CPRI.

Together with remote radio heads from Radiocomp, the test has been publicly showcased in the US for the first time.

Trials of the solution have already been carried out in Japan.

The R&S EX-IQ-Box digital interface module is a flexible solution for connecting signal generators, signal analysers and communications testers from R&S to devices or components with digital baseband inputs and/or outputs.

It allows adaptation to standardised as well as user-specific digital interface formats. The company now extends this test solution to signal generation and reception in line with the common public radio interface (CPRI) protocol standard.

The option EXBOX-B85 for the EX-IQ-Box enables the user to perform tests directly at the CPRI interface between the base station radio equipment control and the base station radio equipment.

Simulation of either the REC or the RE allows independent testing of the RE or REC.

It delivers standardised signals that act as a reference for maintaining the interoperability of products from different vendors.

In the first release, the R&D EXBOX-B85 emulates the REC for testing the RE. Via a future software update, it will also support emulation of the RE for testing the REC.

The connection to the device under test (DUT) is done via the enclosed CPRI specific breakout board, which supports small form factor pluggable modules for the optical CPRI link.

The interface is configured via the enclosed DigIConf configuration software. All standards such as 3GPP FDD (incl HSDPA, HSUPA, HSPA+), LTE, WiMAX and CDMA2000 are supported.

The tests cover individual uplink or downlink operation as well as full duplex operation. Depending on the configuration, up to 24 signal streams with settable sample rates can be processed. Line bit rates of up to 2457.6 Mbps are achieved. Control and management information can be inserted in real time (‘fast C&M’).