Rohde & Schwarz and Nomor Research have developed a real-time solution for generating uplink inter-cell interference signals required for testing LTE networks without having to deploy a large number of base stations. Nomor Research’s system-level simulation can reproduce this interference as experienced by a multi-cell LTE base station, which is then physically generated by signal generators from Rohde & Schwarz.

Rohde & Schwarz and Nomor Research have collaborated on a cost-efficient, real-world solution for generating the uplink inter-cell interference signals required for testing LTE networks. Nomor Research’s system-level simulation realistically reproduces this interference as experienced by a multi-cell LTE base station. The uplink inter-cell interference signal is then physically generated by signal generators from Rohde & Schwarz. The solution elegantly circumvents the costly requirement of deploying a large number of base stations with multiple UEs to simulate realistic load generation. It is suitable for both LTE field trials and in test lab environments.

In LTE, realistic uplink inter-cell interference is essential for testing radio resource management (RRM) algorithms and overall performance. Traditional methods of interference modeling (e.g. using AWGN interference sources) are not reliable because of the particular algorithms used in the OFDMA-based access schemes such as SC-FDMA in LTE uplink. This is especially true at the cell boundaries. Using realistic uplink interference in a lab or field trial environment provides a much better evaluation of the base station‘s receiver performance in real-life conditions.
Nomor Research offers a large number of interference files that conform to the requirements of network operators and are acknowledged as being representative of the interference that future LTE networks are likely to encounter. Files for the standard package modeling uplink interference are provided at no cost under a temporary evaluation license agreement (ELA) from Nomor Research and can be used with any Rohde & Schwarz vector signal generator, e.g. the R&S SMU200A or the R&S SMBV100A.
 
“We saw the first LTE networks coming to life during 2010 and significantly more are expected to start commercial operation in 2011. With growing competition it will be essential to ensure superior performance in real-life conditions without having to conduct expensive and time-consuming tests. The solution developed will greatly assist infrastructure providers and network operators in achieving their goals”, said Hans-Joerg Strufe, Head of Product Management for signal generators at Rohde & Schwarz.

“When LTE networks become popular, they will be more heavily loaded. System performance will no longer be limited by the link budget, but will depend on how the network performs in severe inter-cell interference situations. Already today, our joint test solution allows LTE base stations to be tested in various deployment scenarios under varying load and traffic conditions. This prepares network equipment for large-scale deployment”, said Eiko Seidel, Chief Technical Officer at Nomor Research.

Rohde & Schwarz

Rohde & Schwarz is an independent group of companies specializing in electronics. It is a leading supplier of solutions in the fields of test and measurement, broadcasting, radiomonitoring and radiolocation as well as secure communications. Established more than 75 years ago, Rohde & Schwarz has a global presence and a dedicated service network in over 70 countries. It has approx. 7400 employees and achieved a net revenue of € 1.3 billion in fiscal year 2009/2010 (July 2009 to June 2010). Company headquarters are in Munich, Germany.
R&S ® is a registered trademark of Rohde & Schwarz GmbH & Co. KG

About Nomor Research GmbH
Nomor Research (www.nomor-research.com), based in Munich, Germany, is a leading company in the research and development of future and emerging communication systems that offers related consultancy services and products. Nomor, among other services, is known for its state-of-the-art protocol stack implementations for Long Term Evolution where Nomor offers LTE software modules and related design or integration service used in macro, pico or femtocell base stations or in test equipment.