E. Björnson, A. Papadogiannis, M. Matthaiou, and M. Debbah, On the impact of transceiver impairments on af relaying, 2013 IEEE International Conference on Acoustics, Speech and Signal Processing, 2013.
DOI : 10.1109/ICASSP.2013.6638602

J. N. Laneman, D. N. Tse, and G. W. , Cooperative Diversity in Wireless Networks: Efficient Protocols and Outage Behavior, IEEE Transactions on Information Theory, vol.50, issue.12, pp.3062-3080, 2004.
DOI : 10.1109/TIT.2004.838089

M. O. Hasna and M. Alouini, A Performance Study of Dual-Hop Transmissions With Fixed Gain Relays, IEEE Transactions on Wireless Communications, vol.3, issue.6, pp.1963-1968, 2004.
DOI : 10.1109/TWC.2004.837470

M. O. Hasna and M. Alouini, Harmonic Mean and End-to-End Performance of Transmission Systems With Relays, IEEE Transactions on Communications, vol.52, issue.1, pp.130-135, 2004.
DOI : 10.1109/TCOMM.2003.822185

Y. Yang, H. Hu, J. Xu, and G. Mao, Relay technologies for WiMax and LTE-advanced mobile systems, IEEE Communications Magazine, vol.47, issue.10, pp.100-105, 2009.
DOI : 10.1109/MCOM.2009.5273815

Y. Hua, D. W. Bliss, S. Gazor, Y. Rong, and Y. Sung, Guest Editorial Theories and Methods for Advanced Wireless Relays — Issue I, IEEE Journal on Selected Areas in Communications, vol.30, issue.8, pp.1297-1303, 2012.
DOI : 10.1109/JSAC.2012.120901

E. Costa and S. Pupolin, M-QAM-OFDM system performance in the presence of a nonlinear amplifier and phase noise, IEEE Transactions on Communications, vol.50, issue.3, pp.462-472, 2002.
DOI : 10.1109/26.990908

T. Schenk, RF Imperfections in High-Rate Wireless Systems: Impact and Digital Compensation, 2008.
DOI : 10.1007/978-1-4020-6903-1

C. Studer, M. Wenk, and A. Burg, MIMO transmission with residual transmit-RF impairments, 2010 International ITG Workshop on Smart Antennas (WSA), pp.189-196, 2010.
DOI : 10.1109/WSA.2010.5456453
URL : http://arxiv.org/abs/1002.0406

M. Wenk and M. Testbed, Challenges, Implementations, and Measurement Results, Series in microelectronics. Hartung-Gorre, 2010.

P. Zetterberg, Experimental Investigation of TDD Reciprocity-Based Zero-Forcing Transmit Precoding, EURASIP Journal on Advances in Signal Processing, vol.48, issue.10, 2011.
DOI : 10.1109/25.966592

T. C. Schenk, E. R. Fledderus, and P. F. Smulders, Performance Analysis of Zero-IF MIMO OFDM Transceivers with IQ Imbalance, Journal of Communications, vol.2, issue.7, pp.9-19, 2007.
DOI : 10.4304/jcm.2.7.9-19

D. Dardari, V. Tralli, and A. Vaccari, A theoretical characterization of nonlinear distortion effects in OFDM systems, IEEE Transactions on Communications, vol.48, issue.10, pp.1755-1764, 2000.
DOI : 10.1109/26.871400

E. Björnson, P. Zetterberg, and M. Bengtsson, Optimal coordinated beamforming in the multicell downlink with transceiver impairments, 2012 IEEE Global Communications Conference (GLOBECOM), pp.4775-4780, 2012.
DOI : 10.1109/GLOCOM.2012.6503874

J. Samuel, P. Rosson, L. Maret, C. Dehos, and A. Valkanas, Impact of RF Impairments in Cellular Wireless Metropolitan Area Networks, 2008 IEEE 10th International Symposium on Spread Spectrum Techniques and Applications, pp.766-769, 2008.
DOI : 10.1109/ISSSTA.2008.149

T. Riihonen, S. Werner, F. Gregorio, R. Wichman, and J. Hämäläinen, BEP Analysis of OFDM Relay Links with Nonlinear Power Amplifiers, 2010 IEEE Wireless Communication and Networking Conference, 2010.
DOI : 10.1109/WCNC.2010.5506301

J. Qi, S. A¨?ssaa¨?ssa, and M. Alouini, Analysis and compensation of I/Q imbalance in amplify-and-forward cooperative systems, 2012 IEEE Wireless Communications and Networking Conference (WCNC), pp.215-220, 2012.
DOI : 10.1109/WCNC.2012.6214150

E. Björnson, P. Zetterberg, M. Bengtsson, and B. Ottersten, Capacity Limits and Multiplexing Gains of MIMO Channels with Transceiver Impairments, IEEE Communications Letters, vol.17, issue.1, pp.91-94, 2013.
DOI : 10.1109/LCOMM.2012.112012.122003

E. Björnson and E. Jorswieck, Optimal resource allocation in coordinated multi-cell systems, Foundations and Trends in Communications and Information Theory, pp.113-381, 2013.

M. Matthaiou, A. Papadogiannis, E. Björnson, and M. Debbah, Two-Way Relaying Under the Presence of Relay Transceiver Hardware Impairments, IEEE Communications Letters, vol.17, issue.6, pp.1136-1139, 2013.
DOI : 10.1109/LCOMM.2013.042313.130191

M. Awadin, A. Gomaa, and N. , OFDM AF relaying under I/Q imbalance: Performance analysis and baseband compensation, IEEE Trans. Commun, vol.61, issue.4, pp.1304-1313, 2013.

O. Ozdemir, R. Hamila, and N. , I/Q Imbalance in Multiple Beamforming {OFDM} Transceivers: SINR Analysis and Digital Baseband Compensation, IEEE Transactions on Communications, vol.61, issue.5, pp.1914-1925, 2013.
DOI : 10.1109/TCOMM.2013.021913.120321

H. Zhu and J. Wang, Chunk-based resource allocation in OFDMA systems?Part I: Chunk allocation, IEEE Trans. Commun, vol.57, issue.9, pp.2734-2744, 2009.

B. E. Priyanto, T. B. Sorensen, O. K. Jensen, T. Larsem, T. Kolding et al., Assessing and modelling the effect of RF impairments on UTRA LTE uplink performance, Proc. IEEE Vehic. Techn. Conf. (VTC), pp.1213-1217, 2007.

N. O-'donoughue and J. M. Moura, On the Product of Independent Complex Gaussians, IEEE Transactions on Signal Processing, vol.60, issue.3, pp.1050-1063, 2012.
DOI : 10.1109/TSP.2011.2177264

H. Holma and A. Toskala, LTE for UMTS: Evolution to LTE-Advanced, 2011.
DOI : 10.1002/9781119992943

A. U. Sheikh, M. Handforth, and M. Abdi, Indoor mobile radio channel at 946 MHz: Measurements and modeling, IEEE 43rd Vehicular Technology Conference, pp.73-76, 1993.
DOI : 10.1109/VETEC.1993.507014

C. Studer, M. Wenk, and A. Burg, System-level implications of residual transmit-RF impairments in MIMO systems, Proc. Europ. Conf. Ant. Propag. (EuCAP), pp.2686-2689, 2011.

V. Emamian, P. Anghel, and M. Kaveh, Multi-user spatial diversity in a shadow-fading environment, Proceedings IEEE 56th Vehicular Technology Conference, pp.573-576, 2002.
DOI : 10.1109/VETECF.2002.1040409

G. K. Karagiannidis, T. A. Tsiftsis, and R. K. Mallik, Bounds for multihop relayed communications in nakagami-m fading, IEEE Transactions on Communications, vol.54, issue.1, pp.130-135, 2006.
DOI : 10.1109/TCOMM.2005.861679

D. Senaratne and C. Tellambura, Unified Exact Performance Analysis of Two-Hop Amplify-and-Forward Relaying in Nakagami Fading, IEEE Transactions on Vehicular Technology, vol.59, issue.3, pp.1529-1534, 2010.
DOI : 10.1109/TVT.2009.2038784

M. O. Hasna and M. Alouini, Performance analysis of two-hop relayed transmissions over Rayleigh fading channels, Proceedings IEEE 56th Vehicular Technology Conference, pp.1992-1996, 2002.
DOI : 10.1109/VETECF.2002.1040567

Y. Zhao, R. Adve, and T. J. Lim, Outage probability at arbitrary SNR with cooperative diversity, IEEE Communications Letters, vol.9, issue.8, pp.700-702, 2005.
DOI : 10.1109/LCOMM.2005.1496587

G. Farhadi and N. C. Beaulieu, On the Ergodic Capacity of Wireless Relaying Systems over Rayleigh Fading Channels, IEEE Transactions on Wireless Communications, vol.7, issue.11, pp.4462-4467, 2008.
DOI : 10.1109/T-WC.2008.070737

O. Waqar, M. Ghogho, and D. Mclernon, Tight Bounds for Ergodic Capacity of Dual-Hop Fixed-Gain Relay Networks under Rayleigh Fading, IEEE Communications Letters, vol.15, issue.4, pp.413-415, 2011.
DOI : 10.1109/LCOMM.2011.022411.102027

C. Zhong, M. Matthaiou, G. K. Karagiannidis, and T. Ratnarajah, Generic Ergodic Capacity Bounds for Fixed-Gain AF Dual-Hop Relaying Systems, IEEE Transactions on Vehicular Technology, vol.60, issue.8, pp.3814-3824, 2011.
DOI : 10.1109/TVT.2011.2167362

A. Høst-madsen and J. Zhang, Capacity Bounds and Power Allocation for Wireless Relay Channels, IEEE Transactions on Information Theory, vol.51, issue.6, pp.2020-2040, 2005.
DOI : 10.1109/TIT.2005.847703

A. Weiss, Optimization using symbolic derivatives, Tech. Rep., MATLAB Digest, 2010.

E. Jorswieck and H. Boche, Majorization and Matrix-Monotone Functions in Wireless Communications, Foundations and Trends in Communications and Information Theory, pp.553-701, 2007.
DOI : 10.1561/0100000026

E. Björnson, 12) was born in Malmö, Sweden, in 1983, He received the M.S. degree in Engineering Mathematics from Lund University He received the Ph.D. degree in Telecommunications from the Signal Processing Lab at KTH Royal Institute of Technology 2011. He is the first author of the monograph " Optimal Resource Allocation in Coordinated Multi-Cell Systems " published in Foundations and Trends in Communications and Information Theory, 2007.

. Dr, This grant is currently funding a joint postdoctoral research fellowship at the Alcatel-Lucent Chair on Flexible Radio, Supélec, Paris, France, and the Signal Processing Lab at KTH Royal Institute of Technology His research interests include multi-antenna cellular communications, resource allocation, random matrix theory, estimation theory, stochastic signal processing, and mathematical optimization. For his work on optimization of multi-cell MIMO communications, Björnson was one of the first recipients of the International Postdoc Grant from the Swedish Research Council Best Paper Award at the 2009 International Conference on Wireless Communications & Signal Processing (WCSP) and a Best Student Paper Award at the 2011 IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP)