Project Name: MOBILIA - Mobility Concepts of IMT Advanced
Research Programme: EUREKA CELTIC
Contract Number: CP5-016
Total Financial Volume:
Duration: 30 months (01.04.2008 - 30.09.2010)
MOBILIA project targets ITU IMT-advanced requirements for future wireless systems, i.e. peak data rates of 100 Mbps for mobile applications and 1 Gbps for low mobility. The IMT-advanced vision of future network as being formed of interworking access systems was considered. A derived target was to obtain an increased aggregate throughput/ user satisfaction vs. existing systems. MOBILIA addresses these various challenges, in the context of IEEE802.16m, 802.16j and beyond, 3GPP LTE. MOBILIA addresses the "Integrated Telecommunications system" approach of CELTIC in various ways.
Indeed, future broadband wireless systems will need advanced air interfaces at PHY and System layers, including MIMO techniques, as well as seamless session roaming between access networks, two main research axes of MOBILIA. In addition, in these multi-networks environments, terminals should be reconfigurable, and also optimise power consumption. These two issues are considered in MOBILIA, the latter one through a cross-layer (PHY and MAC) approach. Eventually, implementation issues of the above mentioned concepts will be tackled through proof-of-concept demonstrators and complexity studies. MOBILIA studies the following enabling technologies:
Several platforms will be showcased/developed, as proof-of-concept for the above techniques: a reconfigurable baseband platform, based on a Network-on-chip, reconfigurable multi band RF, reconfigurable multi band multiple antennas, both for base station and for mobile -in this latter case, up to 4 antennas will be integrated in a small terminal-, a reconfigurable terminal for flexible energy trade-off, a WiMAx MIMO demonstrator, a proof-of-concept demonstration inline with the ubiquitous services, connectivity and networks concept, and an example of remote diagnosis mechanism
In MOBILIA Sigint has investigated the potential advantages in terms of capacity improvements of Distributed Antenna Systems (DAS), also known as virtual-MIMO, when compared against conventional MIMO and SISO systems. The spatial channel parameters were calculated using deterministic modeling techniques such as Ray Tracing. More specifically, Sigint's own 3D Ray Tracing simulator 3DTruEMhas been used to simulate the propagation channel parameters for the defined scenarios under investigation. A MIMO capacity add-on module to 3DTruEM (mimoCap) has been developed for this purpose. The module receives the spatial output of 3DTruEM and offers the ability to the user to calculate the upper bound on capacity of any antenna combination (SISO, SIMO, MISO and MIMO).
Multiple-input multiple-output (MIMO) systems, where more than one antenna element is available at each end of the communication link, have become a highly researched area since ground-breaking work during the nineties showed that large increases in capacity over the Shannon limit can be achieved without any increase in the transmit power and/or bandwidth. A MIMO system takes advantage of the spatial diversity that is obtained by spatially separated antennas in a dense multi-path scattering environment. The use of multiple antennas at each side of the communication link exploits the rich scattering channel to create multiplicity of parallel radio links over the same radio band and therefore increase the data rate through multiplexing or increase reliability through the increased antenna diversity gain. Although conventional (single-user) MIMO was proved to offer significant benefits in the performance of radio communication, research goes one step beyond and proposes the concept of cooperative MIMO or "virtual MIMO" or ad-hoc MIMO. Despite the fact conventional MIMO, where multiple antenna elements are placed locally, offer low correlation between the formed channels, this correlation can be reduced further by introducing the concept of cooperative MIMO which utilizes distributed antennas which belong to other users, and effectively increasing capacity.
3DTruEM has been used to simulate the scenarios under investigation and provide the simulation data into a database which acts as an intermediary between the simulator and the MIMO capacity module (mimoCap). The scenarios are: