Multi-functional MIMO communication in multi-hop cellular systems

[EN] 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.This work was performed in the framework of the FP7 project ICT-317669 METIS, which is partly funded by the European Union. The authors would like to acknowledge the contributions of their colleagues in METIS, although the views expressed are those of the authors and do not necessarily represent the project.Roger Varea, S.; Calabuig Soler, D.; Monserrat Del Río, JF.; Cardona Marcet, N. (2014). Multi-functional MIMO communication in multi-hop cellular systems. EURASIP Journal on Advances in Signal Processing. 2014(165):1-9. https://doi.org/10.1186/1687-6180-2014-165S192014165Timus B, Fallgren M (Eds): In D1.1: Scenarios, requirements and KPIs for 5G mobile and wireless system. Project deliverable, ICT-317669-METIS. 2013.Zheng K, Fan B, Ma Z, Liu G, Shen X, Wang W: Multihop cellular networks toward LTE-advanced. IEEE Veh. Tech. Mag 2009, 4(3):40-47.Gozalvez J, Coll-Perales B: Experimental evaluation of multihop cellular networks using mobile relays. IEEE Commun. Mag 2013, 51(7):122-129.Zhou B, Hu H, Huang S-Q, Chen H-H: Intracluster device-to-device relay algorithm with optimal resource utilization. IEEE Trans. Veh. Tech 2013, 62(5):2315-2326.Vanganuru K, Ferrante S, Sternberg G: System capacity and coverage of a cellular network with D2D mobile relays,. In Military Communications Conference,. Orlando (FL), USA; 2012:1-6. doi:10.1109/MILCOM.2012.6415659Bölcksei H, Nabar RU, Oyman O, Paulraj AJ: Capacity scaling laws in MIMO relay networks. IEEE Trans. Wireless Comm 2006, 5(6):1433-1444.Tarokh V, Jafarkhani H, Calderbank AR: Space-time block codes from orthogonal designs. IEEE Trans. Information Theory 1999, 45(5):1456-1467. 10.1109/18.771146Wang H, Xia XG: Upper bounds of rates of complex orthogonal space-time block codes. IEEE Trans. Information Theory 2003, 49(10):2788-2796. 10.1109/TIT.2003.817830Jafarkani H: A quasi-orthogonal space–time block code. IEEE Trans. Commun 2001, 49(1):1-4. 10.1109/26.898239Nguyen XH, Choi J: Joint design of groupwise STBC and SIC based receiver. IEEE Comm. Lett 2008, 12(2):115-117.El-Hajjar M, Alamri O, Wang J, Zummo S, Hanzo L: Layered steered space-time codes using multi-dimensional sphere packing modulation. IEEE Trans. Wireless Comm 2009, 8(7):3335-3340.Laneman JN, Wornell GW: Distributed space-time-coded protocols for exploiting cooperative diversity in wireless networks. IEEE Trans. Information Theory 2003, 49(10):2415-2425. 10.1109/TIT.2003.817829Barbarossa S, Pescosolido L, Ludovici D, Barbetta L, Scutari G: Cooperative wireless networks based on distributed space-time coding,. In International Workshop on Wireless Ad-Hoc Networks,. Oulu, Finland; 2004.Jing Y, Jafarkhani H: Using orthogonal and quasi-orthogonal designs in wireless relay networks. IEEE Trans. Information Theory 2007, 53(11):4106-4118.Hayes M, Kassim SK, Chambers JA, Macleod MD: Exploitation of quasi-orthogonal space time block codes in virtual antenna arrays: Part I - theoretical capacity and throughput gains,. In IEEE Vehicular Technology Conference, VTC Spring 2008,. Singapore; 2008:349-352. doi:10.1109/VETECS.2008.84Zou Y, Yao Y-D, Zheng B: Opportunistic distributed space-time coding for decode-and-forward cooperation systems. IEEE Trans. Signal Process, 60(4):2012.Kim J, Yang JR, Kim DI: Optimal relaying strategy for UE relays,. In Asia-Pacific Conference on Communications (APCC),. Sabah, Malaysia; 2011:192-196. doi:10.1109/APCC.2011.6152803Fan Y, Thompson J: MIMO configurations for relay channels: theory and practice. IEEE Trans. Wireless Commun 2007, 6(5):1774-1786.Schulz B: LTE Transmission Modes and Beamforming. Rohde and Schwarz White Paper 2011.Forutanpour B, Schevciw AGP, Visser E, Momeyer B: Variable beamforming with a mobile platform. US Patent 20120182429 2012