R&S®EX-IQ-Box Digital Signal Interface Module

Test Challenge

Remote Radio Head Test

Rohde & Schwarz offers a complete test setup for RRH verification based on the R&S^®SMU200A vector signal generator or R&S^®AMU200A baseband signal generator and the R&S^®FSQ signal analyzer. Together with the R&S^®EXBOX-B85 and R&S^®EXBOX-K10 options, the R&S^®EX-IQ-Box generates and receives signals in line with the common public radio interface (CPRI™) protocol standard by converting the data accordingly. This enables the user to perform tests directly by using the CPRI™ interface between the base station radio equipment control (REC) and the base station radio equipment (RE). The R&S^®EXBOX-K10 simulates the CPRI™ REC and hereby allows to test the CPRI™ RE independently from the CPRI™ REC in research and development, verification and production. This helps to speed up time to market and to save valuable resources.

Straight-forward connection to the RE is achieved via the CPRI™ specific breakout board (R&S^®EXBOX-B85 option).

Easy CPRI™ interface configuration is ensured by the R&S^®DigIConf configuration software. All state-of-the-art standards such as 3GPP FDD (incl. HSDPA, HSUPA, HSPA+), LTE, WiMAX and CDMA2000 are supported as pre-defined interface settings. Additionally, there is the possibility to manually configure the CPRI™ interface. The test solution covers individual uplink or downlink operation as well as full duplex operation. Control and management information can be inserted in realtime.

In combination with the Rohde & Schwarz signal generators and spectrum analyzers, the R&S^®EX-IQ-Box is able to utilize the enhanced functions of the signal generators (e.g. digital communication standards, fading, AWGN, impairments) and the vast signal analysis features of the spectrum analyzers (e.g. ACP and EVM measurements for digital standards) also at the digital signal interface. I.e. the same tools can be used for generation and analysis of digital baseband signals as they are already familiar from RF measurements. The elaborate CPRI™ test solution from Rohde & Schwarz is a straight-forward approach to test CPRI™ radio equipment and thanks to the scalable concept offers the flexibility to tailor the test solution to your needs.

REC Test

The R&S^®EX-IQ-Box digital interface module is an ideal solution for testing the baseband unit (=radio equipment control, REC) of a base station. By means of the R&S^®EXBOX-K11 CPRI^™ REC test option data is exchanged between the REC and the Rohde & Schwarz measurement equipment in line with the CPRI^™ specification. The optical or electrical connection is done via the R&S^®EXBOX-B85 CPRI^™ breakout board.

In the test setup, the R&S^®EX-IQ-Box acts as the CPRI^™ interface of the RE. Together with a Rohde & Schwarz signal generator and/or analyzer – or the optional waveform memory (R&S^®EXBOX-K90/-K91) and recording memory (R&S^®EXBOX-K94) – the T&M solution substitutes the RF front-end (or CPRI^™ RE). Hereby, the solution allows the engineer to evaluate the performance of the baseband unit of a base station independently from the RF. All important digital communication standards – e.g. 3GPP FDD (incl. HSDPA, HSUPA, HSPA+), LTE, WiMAX and CDMA2000 – can be covered with the same equipment. With a fading simulator as available in the R&S^®SMU200A or R&S^®AMU200A performance tests involving channel emulation can be done directly at the baseband. With additional signal generator options also physical layer procedures like HARQ feedback, timing adjustment or closed-loop power control can be verified. Furthermore, the effects of RF signal delays in distributed network architectures are also simulated easily by means of the fading simulator. Conducting measurements on the I/Q data by using a signal analyzer like the R&S^®FSQ helps to uncover flaws in the CPRI^™ REC implementation.

Direct Signal Generation & Waveform Playback

The R&S^®EX-IQ-Box can be equipped with an internal waveform memory option (R&S^®EXBOX-K90/-K91) which allows playback of pre-calculated waveforms (e.g. generated by R&S^®WinIQSIM2^™ or third-party tools like Matlab™). With R&S^®EXBOX-K91 option up to four waveforms can be played back at the same time. This enables simultaneous transmission of up to four different signals via the same CPRI™ link (e.g. for multi-standard, diversity or MIMO applications). CPRI™ specifc control and management (C&M) data can either be inserted into the CPRI™ link via the R&S^®DigIConf software or in realtime via Ethernet or RS232 connectors on the R&S^®EXBOX-B85 CPRI™ breakout board – no matter whether a signal generator like the R&S^®SMU200A is used for generation of the CPRI™ payload signal (e.g. WiMAX, LTE) or waveform files are played back from the internal waveform memory of the R&S^®EX-IQ-Box.

The waveform playback functionality is available together with the CPRI™ RE test (R&S^®EXBOX-K10) or CPRI™ REC test (R&S^®EXBOX-K11) options.

I/Q Recording

The complementary recording memory option R&S^®EXBOX-K94 captures the I/Q data that is received by the R&S^®EX-IQ-Box via the CPRI^™ link from the DUT. The received I/Q samples are stored in an internal memory of 512 Mbyte and are available for offline signal analysis and customer-specific post-processing by use of third-party tools.

The I/Q recording functionality is available together with the CPRI^™ RE test (R&S^®EXBOX-K10) or CPRI™ REC test (R&S^®EXBOX-K11) options.