Spatial modulation and physical layer network coding based bidirectional relay network with transmit antenna selection over Nakagami‐m fading channels

Abstract

In this paper, a high data rate bidirectional relay network is proposed by combining the merits of spatial modulation (SM) and physical layer network coding. All nodes in the network are equipped with multiple antennas. Spatial modulation technique is used to reduce hardware complexity and interchannel interference by activating only one antenna at any time during transmission. In the proposed bidirectional relay network, transmit antennas are selected at the source nodes and relay node on the basis of the order statistics of channel power. It increases received signal power and provides a significant improvement in the outage performance. Also, the data rate of the proposed network is improved by physical layer network coding at the relay node. A closed form analytical expression for the outage probability of the network over Nakagami-m fading channel is derived and validated by Monte Carlo simulations. In addition, asymptotic analysis is investigated at high signal-to-noise ratio region.The outage performance of the proposed network is compared with SM and physical layer network coding bidirectional relay network without transmit antenna selection and point-to-point SM. With approximate SNR≈1 dB difference between the two networks, the same data rate is achieved. KEYWORDSdecode and forward, Nakagami-m fading channel, physical layer network coding, spatial modulation, transmit antenna selection | INTRODUCTIONThe demand for high data rate and better quality of service is of the utmost importance in next-generation wireless communication systems. The recently proposed spatial modulation (SM) has attracted a great deal of attention in the past few years in 5G wireless networks. 1 In SM, the information bits are partitioned into two streams of which one is mapped to the symbol and the other is used to activate a particular antenna out of all transmit antennas. 2 Therefore, information is carried not only by the symbol but also by the antenna index. When the information bits are transmitted solely through the transmit antenna index, SM is reduced to space shift keying (SSK). 3 Spatial modulation eliminates the synchronization between the transmit antennas and interchannel interference because only one antenna is active during transmission. Hence, only one radio frequency (RF) chain is required in SM because of single antenna transmission at any transmission time slot. Besides these advantages, SM 4 may be flexibly configured for diverse transmit and receive antenna constellations. In multiple-input multiple-output (MIMO) systems, the error performance is directly related to interantenna interference, synchronization, and a significant amount of power consumed due to the number of transmitting RF chains. Studies on SM 5,6 have shown that it is capable of outperforming MIMO transmission techniques with practical implementation constraints. Spatial modulation in previous literatures 7-9 has been proved as an efficient low complexity and energy efficient transmission technique to improve the spectral efficiency and bandw...

C‐MRC–based cooperative spatial modulation with antenna selection

“…Besides, antenna selection techniques have been studied for SM-based schemes in recent years. 30 Euclidean distance and capacity optimization-based antenna selection algorithms are proposed for point-to-point SM systems in Rajashekar et al 31 and Pillay and Xu. 32 Ntontin et al 33 investigated the error performance of SSK with antenna subset selection, while a low-complexity antenna selection method is proposed for SM systems in Ntontin et al 34 Another antenna selection technique based on IM for SM is proposed in Aydin and Ilhan.…”