On the Performance of SR and FR Protocols for OSTBC based AF-MIMO Relay System with Channel and Noise Correlations

This paper proposes selection relaying (SR) protocol for a cooperative multiple-input multiple-output (MIMO) relay system that consists of a direct link between a source and a destination. The system has only receive-side channel state information (CSI), spatially correlated MIMO channels, and the receiver nodes observe spatially correlated noise. The transmit nodes employ orthogonal space-time block codes (OSTBC), whereas the receiver nodes employ optimum minimum mean-square-error (MMSE) detection. The SR protocol, which transmits via the relay only when the direct link between the source and destination is in outage, is compared with the fixed relaying (FR) protocol which always uses the relay. By deriving novel asymptotic expressions of the outage probabilities, it is analytically shown that both protocols provide the same diversity gain. However, the coding gain (CG) of the SR protocol can be much better than that of the FR protocol. In particular, when all MIMO links have the same effective rank, irrespective of its value, the SR protocol provides better CG than the FR scheme if the target information rate is greater than ln2(3) bits per channel use. Simulation results support theoretical analysis and show that the SR scheme can significantly outperform FR method, which may justify the increased complexity due to one-bit feedback requirement in the SR protocol

On the Performance of SR and FR Protocols for OSTBC based AF-MIMO Relay System with Channel and Noise Correlations

This paper proposes selection relaying (SR) protocol for a cooperative multiple-input multiple-output (MIMO) relay system that consists of a direct link between a source and a destination. The system has only receive-side channel state information (CSI), spatially correlated MIMO channels, and the receiver nodes observe spatially correlated noise. The transmit nodes employ orthogonal space-time block codes (OSTBC), whereas the receiver nodes employ optimum minimum mean-square-error (MMSE) detection. The SR protocol, which transmits via the relay only when the direct link between the source and destination is in outage, is compared with the fixed relaying (FR) protocol which always uses the relay. By deriving novel asymptotic expressions of the outage probabilities, it is analytically shown that both protocols provide the same diversity gain. However, the coding gain (CG) of the SR protocol can be much better than that of the FR protocol. In particular, when all MIMO links have the same effective rank, irrespective of its value, the SR protocol provides better CG than the FR scheme if the target information rate is greater than ln2(3) bits per channel use. Simulation results support theoretical analysis and show that the SR scheme can significantly outperform FR method, which may justify the increased complexity due to one-bit feedback requirement in the SR protocol

Outage probability analysis of a MIMO relay channel with orthogonal space-time block codes

We investigate the performance of a cooperative multiple-input multiple-output (MIMO) relay channel in which the source and relay use the same orthogonal space-time block code (OSTBC) for transmission whereas the relay and destination use maximum-ratio-combining (MRC) for reception. Considering that perfect channel state information is available at the relay and destination, we derive a closed-form expression for the outage probability of the destination signal-to-noise ratio (SNR) in terms of the confluent hypergeometric function of two variables in a Rayleigh flat-fading environment. The validity of the closed-form expression is confirmed with the numerical results

Sobre a capacidade-soma e a probabilidade de bloqueio em canais de múltiplos usuários equipados com múltiplas antenas

Orientadores: Gustavo Fraidenraich, Behnaam AazhangTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: O uso de múltiplas antenas em comunicações sem fio permitiu, inicialmente, garantir que um sinal transmitido fosse recebido com maior energia, o que diretamente aumenta a probabilidade de sucesso na recuperação dos dados transmitidos. Posteriormente, foi possível aumentar a capacidade de uma comunicação sem fio utilizando múltiplas antenas transmitindo e recebendo ao mesmo tempo. Atualmente, os dispositivos móveis como telefones celulares e computadores pessoais já são equipados com múltiplas antenas garantindo uma flexibilidade entre taxas maiores, quando as condições são favoráveis, ou aumento da confiabilidade de recepção, em condições menos favoráveis. Além dos graus de liberdade trazidos com a utilização de múltiplas antenas para uma comunicação ponto-a-ponto, os benefícios para uma rede onde um ou mais elementos façam uso destas é notável. Neste trabalho, apresentamos um estudo sobre o impacto do uso de múltiplas antenas em diversos tipos de redes compostas por múltiplos usuários fazendo uso do canal sem fio ao mesmo tempo. Como será visto, em algumas situações o objetivo será reduzir a probabilidade de que ocorra uma falha na comunicação, havendo ou não interferência. Em outras situações, faremos um estudo da capacidade soma de vários usuários ao transmitirem ao mesmo tempo. Em todos os casos, o conhecimento ou não do canal no transmissor é fator determinante para decidir como os sinais serão distribuídos nas múltiplas antenas do transmissor e se estes estarão sujeitos a uma probabilidade de bloqueio ou uma determinada capacidade. Em todos os casos, para uma dada configuração da rede (número de transmissores, receptores), iremos obter a métrica adequada em função da relação sinal ruído e apresentaremos uma modelagem teórica do problema comparando os resultados propostos com simulações de forma a validar estes resultadosAbstract: The first use of multiple antennas in wireless communications aimed to the improvement of the reliability of a transmission by improving the signal to noise ratio at receiver. More energy of the desired signal means that the receiver has higher probability to correctly decode the transmitted signal. Later, it was possible to increase the capacity of a wireless communication by the use of multiple antennas to transmit and receive at the same time. Nowadays, even the inexpensive mobile devices such as smartphones and personal computers are equipped with multiple antennas that provide flexibility between more data rate in favourable channel situations and more reliability in poor channel conditions. Besides the degrees of freedom that multiple antennas provide in single user communication, it dramatically increases the network data rate. In this work, we study the impact of multiple antennas in several multi-user scenarios with concurrent transmission. Whenever is possible, we provide closed-form expressions or approximations for outage probability or sum capacity depending on the type of network. The derived expressions allow us to quantify the impact of the number of users and number of antennas in the performance of the network. We quantify either outage or sum capacity in terms of signal-to-noise ratio for channels under fading conditionsDoutoradoTelecomunicações e TelemáticaDoutor em Engenharia Elétrica10714/14-6CAPESBE

Outage Probability For Mimo Relay Channel

The channel capacity for the multiple-input multiple-output (MIMO) relay channel is still an open problem. In view of this gap, upper and lower bounds were found by Wang et al., 2005. This paper presents an extensive study of mutual information and outage probability of Rayleigh fading MIMO relay channels based on the eigenvalues distribution for the sum of complex Wishart matrices. Interestingly, for certain scenarios, upper and lower bounds are coincident providing the real channel capacity. To compute outage probability, a Gaussian approximation for mutual information has been used. Furthermore, it was proposed an equivalent distribution for the sum of Wishart matrices, which proves to be excellent in all scenarios. Closed-form expressions for probability density function and outage probability have been found for the general case of any number of antennas and any SNR values. Analytical expressions have been validated by means of Monte Carlo simulations.621137913800Wang, B., Zhang, J., Host-Madsen, A., On the capacity of MIMO relay channels (2005) IEEE Trans. Inf. Theory, 51 (1), pp. 29-43. , JanRappaport, T.S., Wireless Communications: Principles and Practice, , Upper Saddle River, NJ, USA: Prentice-Hall, 2002, ser. Prentice Hall Communications Engineering and Emerging Technologies SeriesTelatar, E., Capacity of multi-antenna Gaussian channels (1999) Eur. Trans. Telecommun., 10 (6), pp. 585-595. , NovDohler, M., Li, Y., (2010) Cooperative Communications, , Chichester U.K.: Wiley, FebSklar, B., Digital Communications: Fundamentals and Applications, , Upper Saddle River, NJ, USA: Prentice-Hall, 2001, ser. Prentice Hall Communications Engineering and Emerging Technologies SeriesWang, Z., Giannakis, G., Outage mutual information of spacetime MIMO channels (2004) IEEE Trans. Inf. Theory, 50 (4), pp. 657-662. , AprFan, Y., Thompson, J., MIMO configurations for relay channels: Theory and practice (2007) IEEE Trans. Wireless Commun., 6 (5), pp. 1774-1786. , MayChalise, B., Vandendorpe, L., Outage probability analysis of a MIMO relay channel with orthogonal space-time block codes (2008) IEEE Commun. Lett., 12 (4), pp. 280-282. , AprJayasinghe, L.K.S., Rajatheva, N., Dharmawansa, P., Latva-Aho, M., Noncoherent amplify-and-forward MIMO relaying with OSTBC over Rayleigh Rician fading channels (2013) IEEE Trans. Veh. Technol., 62 (4), pp. 1610-1622. , MayLoyka, S., Levin, G., On outage probability and diversity-multiplexing tradeoff in MIMO relay channels (2011) IEEE Trans. Commun., 59 (6), pp. 1731-1741. , JunHe, W., Georghiades, C., Computing the capacity of a MIMO fading channel under PSK signaling (2005) IEEE Trans. Inf. Theory, 51 (5), pp. 1794-1803. , MayGirnyk, M.A., Vehkapera, M., Rasmussen, L.K., Large-system analysis of the K-hop AF MIMO relay channel with arbitrary inputs (2013) Proc. IEEE Int. Symp. Inf. Theory, Jul., pp. 439-443Marzetta, T., Hochwald, B., Capacity of a mobile multiple-antenna communication link in Rayleigh flat fading (1999) IEEE Trans. Inf. Theory, 45 (1), pp. 139-157. , JanGoodman, N.R., Statistical analysis based on a certain multivariate complex Gaussian distribution (an introduction) (1963) Ann. Math. Statist., 34 (1), pp. 152-177. , MarJames, A.T., Distributions of matrix variates and latent roots derived from normal samples (1964) Ann. Math. Statist., 35 (2), pp. 475-501. , JunSimon, M., Alouini, M., Digital Communication over Fading Channels, , Hoboken, NJ, USA: Wiley, 2005, ser. Wiley series in telecommunications and signal processingPapoulis, A., Pillai, S.U., Probability Random Variables, Stochastic Processes, , Noida, India: Tata McGraw-Hill, 2002, ser. McGraw-Hill series in electrical engineering: Communications and signal processingNadarajah, S., Kotz, S., Exact distribution of the max/min of two Gaussian random variables (2008) IEEE Trans. Very Large Scale Integr. (VLSI) Syst., 16 (2), pp. 210-212. , FebEaton, M., Multivariate Statistics: AVector Space Approach, , Beachwood, OH, USA: Inst. Math. Statist. 1983, ser. Lecture Notes-Monograph SeriesParis, J.F., Lopez-Martinez, F.J., Martos-Naya, E., On the connection between Gaussian Q-functions and a class of hypergeometric functions: Application to LCR of lognormal processes (2013) IEEE Commun. Lett., 17 (8), pp. 1493-1496. , AugGradshteyn, I., Ryzhik, I., (2007) Table of Integrals, Series, Products, , New York, NY, USA: Academi