Graduate School and Research Center in Digital Sciences

Seminar: Mode Selection and Transceiver Design for Rate Maximization in Underlay D2D MIMO Systems

Antti Tölli - Professeur Associé

Communication systems

Date: October 27, 2015

Location: Eurecom - Salle SHANNON

Title: Mode Selection and Transceiver Design for Rate Maximization in Underlay D2D MIMO Systems Abstract: Linear coordinated transmit-receive beamforming methods are proposed for spatial underlay direct device-to-device (D2D) communication in cellular networks where both user terminals (UT) and base stations (BS) employ multiple antenna elements. For a D2D terminal pair, direct communication is a beneficial alternative compared to the cellular mode, where the direct data is relayed via BS. The transmitter and receiver design is formulated as a weighted sum-rate (WSR) maximization problem subject to individual transmit power constraints at BSs and users, where the utility is the aggregate sum of end-to-end data rates carried via uplink, downlink, and D2D links. The direct D2D links are allowed to co-exist with the cellular connections. The original problem is reformulated as an equivalent log-MSE minimization problem allowing alternating optimization of the transmit and receive beamformers. The precoder optimization step is efficiently solved using successive convex approximation (SCA) of the non-convex objective and constraints. First, a centralized solution is considered, after which a more practical decentralized optimization framework utilizing combination of alternating direction method of multipliers (ADMM) and bidirectional signalling concepts is introduced. According to the results, the system performance can be significantly improved with efficient mode selection between the BS and D2D transmission as opposed to solely serving all the users via D2D links or BS. Also, in certain scenarios, it is beneficial to allow a multi-route connection between the UTs. Bio: Antti Tölli (M'08, SM'14) received his Dr.Sc (Tech) degree in electrical engineering from the University of Oulu, Oulu, Finland in June 2008. Before joining the Department of Communication Engineering (DCE) and Centre for Wireless Communications (CWC) at the University of Oulu, he worked five years for Nokia Networks, IP Mobility Networks division as a Research Engineer and Project Manager both in Finland and Spain. In May 2014, he was granted a five year (2014-2019) Academy Research Fellow post by the Research Council for Natural Sciences and Engineering of the Academy of Finland. He also holds an Adjunct Professor position at the DCE of the University of Oulu. During the academic year 2015-2016, he holds a visiting position at EURECOM Institut, Sophia Antipolis, France. He served as a General co-chair of IEEE WDN in 2010 and 2011, as well as Finance chair in IEEE CTW 2011. His main research interests are in radio resource management and transceiver design for broadband wireless communications with a special emphasis on distributed interference management in heterogeneous wireless networks. A. Tölli has published more than 120 papers in peer-reviewed international journals and conferences, as well as, several patents all in the area of signal processing and wireless communications. Detailed list of publications is available at

Mode Selection and Transceiver Design for Rate Maximization in Underlay D2D MIMO Systems