Test sol'n targets microwave, mm-wave spectrum within 5G

Rohde & Schwarz, in partnership with Fraunhofer Heinrich Hertz Institute (HHI), is set to unveil a 5G channel sounding solution, which combines the R&S SMW200A vector signal generator and the R&S FSW signal and spectrum analyser with a synchronisation unit and application software from Fraunhofer HHI. The test solution is intended for research activities aimed at the microwave and millimetre-wave spectrum within 5G networks.

For decades, propagation conditions in cellular networks have been well understood in the frequency bands from 450MHz to 3GHz. Starting with the commercialisation of GSM systems, channel models were developed based on this knowledge. These are widely used to verify base station and end user device performance in the lab by simulating real-world conditions. In contrast to these legacy frequency bands, knowledge of the radio channel at frequencies above 6GHz is still limited. Although a significant amount of channel sounding campaigns have been conducted and many results published, new spectrum in the discussed range from 6GHz to 100GHz requires much more measurement data. Multiple research projects as well as the upcoming 3GPP standardisation need comprehensive measurement data in order to derive suitable channel models for efficient testing in future.

The solution demonstrated comprises the R&S SMW200A vector signal generator and the R&S AFQ100B I/Q baseband generator on the transmitter end and the R&S FSW signal analyser on the receiver end. The transmitter and receiver are synchronised and triggered by high-precision clocking units from Fraunhofer HHI, which also serve as absolute time bases with an accuracy of 2ns. The R&S SMW200 and R&S AFQ100B provide a wideband sounding signal with up to 500MHz signal bandwidth and up to 40GHz carrier frequency. The sounding signal is based on an optimized correlation sequence. The R&S FSW receives this signal up to a carrier frequency of 67GHz, and demodulates and samples it using its built-in 500MHz demodulator. Application software from Fraunhofer HHI post-processes the demodulated signal and estimates channel impulse responses in the time and delay domains. The same measurement concept could be extended for measurements above 40/67GHz by adding external up/downconverters on both ends. A 2GHz demodulation bandwidth could also be realised using a wideband I/Q baseband generator from Fraunhofer HHI on the transmitter end and by adding the R&S RTO oscilloscope as well as the R&S FSW-B2000 frequency range extension option for the R&S FSW on the receiver end. This flexible solution would provide an excellent dynamic range with a multipath resolution down to 0.5ns.

Rohde & Schwarz and Fraunhofer HHI will demonstrate their solution at the NGMN Industry Conference & Exhibition, which takes place March 24-25, 2015, in Frankfurt/Main.