Europe Germany : MIMO technology operates with multiple transmit and receive antennas to make transmission as reliable as possible. By introducing a new option for its R&S FSQ and R&S FSG signal analyzers, Rohde & Schwarz is enabling manufacturers of 3GPP LTE base stations for the first time to perform measurements on systems with up to four transmitters.

For standards such as 3GPP LTE or WiMAX, 2x2 MIMO systems are currently being used. To test MIMO transmitters for 3GPP LTE, Rohde & Schwarz has launched the R&S FSQ-K102 option. This scalable test solution supports measurements with a signal analyzer as well as the parallel analysis of multiple antenna signals by means of up to four signal analyzers. This means that tests on 4x4 MIMO systems are now also possible.

There are two methods for assigning a signal to existing antennas: transmit diversity and spatial multiplexing. Manufacturers of base stations choose one of these alternatives to precode the signal in the transmitter. The R&S FSQ-K102 option makes it possible to display the constellation diagram before and after MIMO decoding. This helps the user to determine whether the precoding for MIMO is properly implemented in the 3GPP LTE base stations. In addition, users will be able for the first time to determine the modulation quality of 3GPP LTE MIMO signals. Key parameters such as EVM, EVM for the single carriers, spectral flatness or transmit power may also be measured.

The high-end R&S FSQ and R&S FSG signal analyzers boast excellent RF characteristics and low EVM values. All measurements can be performed in the RF range or optionally in the baseband.

For tests on MIMO transmitters for 3GPP LTE, the R&S FSQ-K100 and R&S FSQ-K102 options are required.