ALCATEL-LUCENT : Smart-RF research develops flexible solutions for future mobile broadband networks

Research project provides a breakthrough for flexible base station deployment with solutions for new reconfigurable radio frequency (RF) transmitters

Berlin/Stuttgart, May 30, 2012 - Alcatel-Lucent (Euronext Paris and NYSE: ALU) today announced that the Smart-RF research project - undertaken by a consortium of companies led by Bell Labs - achieved a major breakthrough for base station deployment. The group developed the technical foundation for a new reconfigurable radio frequency (RF) transmitter capable of supporting different wireless standards within a single radio frequency band. A programmable radio module will help network operators to deploy their base stations more flexibly. This is an advantage when they roll out new wireless standards - such as future generations of long term evolution (LTE) mobile broadband technology - or accommodating new spectrum allocations. This will provide an effective solution for mobile operators as they evolve their networks to meet customers' growing demands for the latest services and applications, in a more cost-efficient manner.

Reprogrammable radio modules mean that fewer hardware variants are required for base stations, the primary element of radio access networks (RAN). This means significantly greater flexibility compared with current commercial single-RAN and converged-RAN solutions, which generally accommodate individual frequency specific radio modules within a base station.

Dr. Andreas Pascht, who is responsible for transceiver technologies at Bell Labs, Alcatel-Lucent's research arm, said: "The results of the project show that carriers will be able to operate mobile communications networks with greater flexibility than ever before. Hardware with the versatility to cover various wireless standards and carrier frequencies gives them the flexibility to decide which standards and frequencies are most suitable for a given deployment."

This project is part of a continuum of research being conducted by Bell Labs into future architectures for mobile networks, including the breakthrough lightRadio™ portfolio of products.

About the Smart-RF research project

The Smart-RF research project began in May 2007 and was funded by the German Federal Ministry of Economics and Technology. The consortium has been led by Alcatel-Lucent's Bell Labs and consisted of Kathrein, Rohde & Schwarz, Deutsche Telekom, Signalion, Fraunhofer Institute for Telecommunications Heinrich Hertz Institute (FhG-HHI) and the Department of Microwave Engineering of the Technical University of Berlin.

The goal of the project was to develop and test methods and concepts to jointly optimize the analog and digital sections of base station transceivers. The work of the project partners ranged from the conceptual design of the solutions to developing algorithms and RF transceiver hardware modules for base stations.

The study of new algorithms and hardware concepts was prompted by a significant rise in wireless data traffic, which is increasingly pushing today's transceivers to their limits.

The consortium developed the following research solutions:

Bell Labs and FhG-HHI focused on sophisticated algorithms to compensate for nonidealities of very wide-band analog components. These algorithms permit the largely interference-free "upmixing" of transmission signals to a transmission frequency between 400 MHz and 3 GHz, therefore covering the major mobile communications bands. Furthermore, the two partners developed algorithms for the linearization of multi-band transmit amplifiers, improving linearity and enhancing the energy efficiency of the multi-band amplifier and thus of the entire base station. Based on externally available components, Bell Labs also studied very wide-band transmit and feedback paths. A feedback path permits adaptive linearization and thus energy-efficient operation of the transmit amplifier.

The RF transmitter includes several multi-band-capable hardware components, such as very wide-band transmit amplifiers. To this end, Bell Labs developed a multi-stage amplifier module operating in Class AB and covering 900 MHz of bandwidth, while the Department of Microwave Engineering of the Technical University of Berlin worked on a very wide-band, energy-efficient final Doherty power amplifier stage.

Kathrein's contribution was the development of a multi-band/multi-standard duplex filter for 1.8 GHz (GSM) and 2.1 GHz (UMTS) that splits the antenna signal into the two transmit and receive bands. Duplex filters for mobile radio systems with separate frequency bands for the outgoing and return channels (frequency division duplex - FDD) previously acted as bottlenecks for the transmissible bandwidth. Kathrein also developed a multi-band antenna covering 790 MHz to 3.8 GHz with independently adjustable downtilt for each cellular band that contributes to a more efficient coverage of the immediate vicinity and reduced cell interference. 

Rohde & Schwarz contributed highly linear transmitter amplifiers that support a variety of wireless standards under difficult conditions. These efficiency-optimized transmitter amplifiers will be deployed in the company's future software-defined radio components.

Signalion developed a new laboratory technique for evaluating radio transmission methods to permit the simple construction of prototypes and wireless demonstrators. The focus of the research project is on multi-antenna systems and the capability of jointly evaluating analog and digital processes to support optimal analog-digital partitioning of signal processing methods. The project partners have already used this new laboratory technique successfully.

Further use of research results
The research results of the consortium will contribute to the companies' future product developments. For example, Alcatel-Lucent intends to apply its Bell Labs´findings in architecture and algorithms to its upcoming product generations.

[1] An octave is a measure for a large bandwidth ratio, in this case covering about 30 to 512 MHz

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