Submission for demo session at Globecom

Title: Fragmented spectrum and asynchronous multi-user for 5G systems – Filter Bank multi-carrier Physical layer.

  • Proponent’s Name

Dimitri KTENAS – dimitri.ktenas@cea.fr

  • Proponent’s Institution

CEA-Leti: French Atomic and Alternative Energy Commission – Electronics and Information Technology Institute, Grenoble, FRANCE

  • Proponent’s CV

Dimitri Kténas received the Dipl.-Ing. degree in Electrical Engineering from the Ecole Nationale Supérieure d’Electronique et de Radioélectricité (ENSERG), Grenoble (France), in 2001. From that time, he has been with CEA-Leti in Grenoble, France. His main current research interests are PHY and cross-layer optimization for 5G cellular networks. He has been involved in several European projects (4MORE, CODIV, UNITE, ARTIST4G, iJOIN, 5GNOW, LEXNET) and was the coordinator of the French OPUS project that dealt with LTE optimisation. Since 2010, he is leading the Wireless Communication System Studies laboratory within CEA-Leti, which is in charge of baseband processing and MAC layer studies for wireless systems. Dimitri Kténas has published 30+ scientific papers in international journals and conference proceedings and 1 book chapter, and is the main inventor or co-inventor of 10+ patents.

  • Introduction and motivation

The advent of the Digital Agenda and the introduction of carrier aggregation are forcing the transmission systems to deal with fragmented spectrum. 3GPP/LTE-A is already dealing with some spectrum agility as a requisite to allow worldwide interoperability of devices in a fragmented spectrum. In this context, one scenario under consideration is uplink (UL) asynchronous multi-user access on fragmented spectrum for 5G with non-orthogonal waveform. The objective is to allow relaxing both time/frequency synchronization constraints while enabling flexible fine-grained sharing of fragmented spectrum. If the spectral needs are not met in a contiguous space of spectrum, then some form of aggregation should be realized. The specific nature of the fragmented spectrum and the stringent requirements on adjacent band leakage are suggesting a new approach for the PHY layer using filter bank modulation (FBMC) and spectrum pooling techniques.

  • Scientific and technical description

Relaxed synchronization and access to fragmented spectrum are considered for 5th generation of wireless cellular networks. Frequency Division Multiple Access for Filter Bank Multicarrier (FBMC) modulation provides promising performance without strict synchronization requirements contrary to conventional Orthogonal Frequency Division Multiplexing. In FBMC, a set of parallel data symbols are transmitted through a bank of modulated filters. The choice of the prototype filter controls the localization in frequency of the generated pulse and provides better adjacent channel leakage performance in comparison to OFDM. Offset Quadrature Amplitude Modulation (OQAM) combined with Nyquist constraints on the prototype filter is used to guarantee orthogonality between adjacent symbols and adjacent carriers while providing maximum spectral efficiency.  The demonstration will highlight the advantages of FBMC compared to OFDM in the context of fragmented spectrum and asynchronous multiuser access for the uplink of beyond 4G systems. This work is part of the European 5GNOW project (www.5gnow.eu), which is questioning the design targets of LTE and LTE-Advanced and the obedience to strict synchronism and orthogonality.

  • Implementation and use

We plan to present a reconfigurable FPGA/ARM digital baseband hardware platform implementing fragmented spectrum processing both at transmit and receive parts using FBMC modulation and aiming at demonstrating the FBMC built-in filtering feature adapted to spectrum availability in the fragmented case. The proposed multi-user receiver architecture based on frequency domain processing combined with the fair frequency localization of the FBMC prototype filter provides an architecture that allows for more efficient multiuser asynchronous reception compared to OFDM. The objective of the demonstration is thus to prove the feasibility of FBMC multiuser access (FBMC-MA) in a multiuser asynchronous environment.

  • Information about the equipment to be used

The setup will be composed of two user equipments (transmitters) and one receiver (acting as a base station). Real time transmission will be done through RF front ends at 2.7GHz via the National Instrument NI PXIe-1062 equipment.  The application running on top of the physical layer is uplink video conference service and we demonstrate the robustness of FBMC compared to OFDM in the case of timing misalignment between the two user equipments (multi-user asynchronous access).

The multiuser receiver architecture has been implemented on a Xilinx Kintex-7 (XC7K325T) FPGA of a custom-based platform developed by CEA-Leti. The design has been mapped using a 130MHz clock frequency for the FPGA. The receiver is designed for the 10MHz LTE parameters, i.e.: FBMC carriers are separated by 15kHz, the overall bandwidth of the receiver is equal to 10MHz. The implementation is designed to receive any aggregation of resource block (i.e. 12 consecutive carriers) inside a 10MHz bandwidth sent by the two non-synchronized user equipment terminals. Out-of-band signaling sets the configuration of each user equipment (i.e.: which frequency resource blocks are allocated for each user). The control part (light MAC) is implemented on an ARM microcontroller DM3730CBP100 (cortex A-8).

  • Space needed and setup time required

We need a table (at least 140x80cm) and the setup time is one hour.

  • Preview of the demo

The demo is illustrated below, along with a poster given more details on the setup and the results.

ALU Demo

Bell Labs Alcatel-Lucent 5G UFMC Air Interface Demonstrator

Johannes Koppenborg, Thorsten Wild, Frank Schaich, Holger Heimpel, Hans-Peter Mayer, Dragan Samardzija, Alcatel-Lucent Bell Labs


Application scenarios, such as Internet of Things, Gigabit wireless connectivity, tactile Internet, and many more, expected for the fifths generation (5G) of cellular communication systems reveal major Shortcomings of LTE/LTE-A. However, tremendous efforts must be spent to collect the gains and to manage such systems under the premise of strict synchronism and orthogonality.

The advent of the Digital Agenda and the introduction of carrier aggregation are forcing the transmission systems to deal with fragmented spectrum. Moreover, the fraction of machine-type-communications (MTC) is growing fast. In fact, the massive wireless connectivity of machines with other machines, referred to as M2M or the Internet of Things (IoT), is the next foreseen killer application. Such sporadic traffic generating devices (e.g., MTC devices in the IoT) should not be forced to be integrated into the bulky synchronization procedure of LTE-A PHY layer random access. Given these requirements, it is widely accepted that new 5G air interfaces are needed.

A new waveform approach “Universal Filtered Multi-Carrier” (UFMC), being better suited for 5G has been invented by Bell Labs.   The new waveform supports reduced interference between synchronous and asynchronous traffic and a significant spectral side lobe level reduction which lease to a higher spectral efficiency.

A live demo of synchronous and asynchronous traffic will be presented and compared with OFDM. A high speed Video with synchronous broadband traffic and an application with an asynchronous MTC application will be shown simultaneously with UFMC. To visualize the big advantages of UFMC the same scenario can be shown with OFDM.


TUD Demo

GFDM: A Flexible Waveform for Future Wireless Networks

Future Wireless Networks generation mobile networks are expected to support a variety of applications and diverse requirements that goes the standard OFDM solutions. Vodafone Chair, an integrant of the Dresden 5G Lab, is conducting investigations into a new modulation scheme termed GFDM (Generalized Frequency Division Multiplexing). In the context of the 5GNOW project, we present a proof-of-concept implementation based on National Instruments’ software defined radio platforms. The setup considers a complete transceiver chain encompassing a SISO link and a channel emulator to allow the investigation of many aspects of future flexible PHY approaches.