Enhanced Wireless Communication Systems Employing COoperative DIVersity
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Wireless systems are one of the key components for enabling the information society. Wireless networks and related services will become as pervasive as microprocessors are today. Therefore it is expected that the demand for wireless services will continue to increase in the near and medium term, calling for more capacity and putting more and more pressure on the spectrum availability. To efficiently employ the scarce radio resources and ensure a certain degree of fairness there is need to develop techniques that explore in a quasi-optimal way all the dimensions provided by the space / time and frequency domains.

In wireless communications the path towards high spectral efficiency transmission techniques has been through the use of the diversity provided by the rich scattering wireless channels. Diversity is inherent and well known in the physical layer and either time, frequency, space (antenna) or polarization diversity has been used to combat the fading by trying to stabilize the channel. Diversity can also be achieved in the MAC or higher layer, which is termed network diversity, which can be divided in multiuser diversity (by scheduling or routing) and cooperative diversity (by cooperative transmission). This type of diversity exploits the channel fluctuations to ‘ride the peaks’.

There has been in the recent past significant research activity concerning both aspects, but while research concerning the first topic has already taken a very practical flavor with proposals / technological evaluation and integration of solutions that combine the spatial diversity with the ones provided in the frequency and time domains, research on cooperative channels has been mainly addressed within the information theory community. Since both aspects provide potential gains, and considering that for achieving broadband wireless communications it will be necessary to explore in a quasi-optimal way all the dimensions provided by the space / time and frequency domains, we feel that there is still significant need for research in order to design wireless terminals and base stations that integrate and explore all the potentialities associated with the wireless medium and user´s resources. These provided the main impetus for this project proposal whose key objectives are:

To develop and optimize combinations of physical and network diversity to increase network capacity, robustness and fairness, and demonstrate their feasibility.

FP7 ICT - 2007 - 215477

 Last edited: Januar 17, 2008 16:03h. © Instituto de Telecomunicacoes, Aveiro - Portugal  -  all rights reserved.