Multi-functional MIMO communication in multi-hop cellular systems: Doc 719

• Published in: EURASIP journal on advances in signal processing 2014-11, Vol.2014, p.1
• Main Authors: Roger, Sandra, Calabuig, Daniel, Monserrat, Jose F, Cardona, Narcis
• Format: Article
• Language: English
• ISSN: 1687-6172; 1687-6180
• DOI: 10.1186/1687-6180-2014-165

In the context of multi-hop cellular communications, user equipment devices (UEs) with relaying capabilities provide a virtual infrastructure that can enhance the cell spectral efficiency. UE relays, which are generally transparent to the destination user and lack channel state information, mainly operate in an open-loop mode. Most open-loop transmission techniques for relaying are based on orthogonal space-time block coding (OSTBC), which offers a good trade-off between performance and complexity. In this paper, we consider the concept of multi-functional multiple-input multiple-output (MIMO) transmission, which combines OSTBC with beamforming techniques. This concept is applied to networks with multiple relays, which can offer a high number of antennas to implement multi-functional MIMO techniques. The proposed schemes are shown to reduce the bit error rate of the destination user with respect to a direct transmission from the base station (BS). Furthermore, the multi-functional setup exhibits better performance than conventional OSTBC at high transmission rates.[PUBLICATION ABSTRACT]