Elsevier

Physical Communication

Volume 28, June 2018, Pages 147-153
Physical Communication

Full length article
Wireless powered cooperative communications with direct links over correlated channels

https://doi.org/10.1016/j.phycom.2018.03.013Get rights and content

Abstract

In this paper, we investigate the impact of correlated channels on the wireless powered cooperative networks, where the direct links between the source and destination exist and are correlated with the relaying links. In the considered system, the time switching-based relaying protocol of simultaneous wireless information and power transfer is used. In order to enhance the system performance, a better branch between the relaying link and the direct link is selected. We evaluate the system transmission performance by deriving the closed-form expression on outage probability as well as the asymptotic results for the proposed scheme, in the high regime of transmit power. Based on the theoretical analysis, we investigate the effects of the system parameters, such as channel correlation coefficient, average channel fading power, energy harvesting coefficient and slot allocation coefficient, on the system outage probability. Numerical results are provided to verify the theoretical analysis.

Introduction

In recent years, many wireless techniques have arisen to tackle with the explosively increasing data transmission service [[1], [2], [3], [4], [5]]. Among these techniques, relaying is a promising technique to increase the wireless coverage, improve the transmission capacity without requiring additional transmit power [[6], [7]]. In addition, energy harvesting (EH) technique, which can collect wireless power from the environment, is a potential solution for future wireless networks [[8], [9], [10]]. Without battery deployment, energy harvesting scheme can provide low cost and convenient option for long-term low-power communications.

Due to the excellent characteristics of energy harvesting, it has attracted much attentions in both academic and industry area [[11], [12]]. Based on the simultaneous wireless information and power transfer (SWIPT) with perfect and imperfect channel state information, Ref. [13] focused on the transmission power minimum for multiple-input single-output multicasting systems, while optimal mode switching algorithm is studied in [14]. Moreover, joint antenna selection and transmit covariance matrix design optimization problem for energy harvesting systems is investigated in [15]. There are some other extended works on the transmission security for the wireless networks [[16], [17], [18], [19]].

On the other hand, selection diversity has been widely studied to improve the reliability of the wireless links by exploiting the freedom of the multiuser systems [[20], [21], [22], [23], [24]]. Also, user selection scheme can be joint designed with other emerging wireless technologies. For example, Ref. [9] proposed joint source and relay selection for cooperative non-orthogonal multiple access (NOMA) systems. Based on the wireless edge caching deployment, Ref. [25] analyzed the outage performance as well as their diversity order and coding gain with different caching placement solutions. While Ref. [26] investigated the secure relay and jammer selection for physical layer security in terms of secrecy outage probability.

Moreover, wireless energy harvesting can be compatible with cooperative networks [27]. Considering an amplify-and-forward relaying network with energy constrains, Ref. In [28], the authors proposed both time switching-based and power splitting-based relaying protocols. In particular, at low SNR, the time switching-based protocol outperforms the power splitting-based protocol. As an extension, a time-switching based energy harvesting and information transmission protocol is proposed in [29] using intelligent slot allocation scheme. Results show that the proposed continuous time EH outperforms the fixed time-duration EH scheme. Besides, the outage performance for energy harvesting relay-aided cooperative network is analyzed in [30] by deriving closed-form expression of outage probability.

Most of the above works ignoring the direct links from the source to the destinations. In the severe shadowing case, it is reasonable to assume that there is no direct links from the source to the destinations. However, in the moderate shadowing environments, there usually exist direct links which can be useful to improve the performance of the cooperative systems. On the other hand, the theoretical analysis is more complicated due to the combination of the direct links and the relay links [21]. There are some insight works on the role of the direct links for the cooperative systems [[31], [32], [33], [34]].

In this paper, we investigate the outage probability with selection combination for wireless powered relaying system with the help of a direct links. In the considered system, the time switching-based relaying protocol of simultaneous wireless information and power transfer is used. In order to enhance the system performance, a better branch between the relaying link and the direct link is selected. We derive the closed-form expression on outage probability as well as the asymptotic results for the proposed scheme. Based on the theoretical analysis, we find that the large channel correlation coefficient can be benefit to the outage performance, while it has no effect on the diversity order.

Notations

We use CN(μ,σ2) to represent the circularly symmetric complex Gaussian random variable with mean μ and variance σ2, fX(x) and FX(x) denote the probability density function and cumulative distribution function of a random variance X, respectively, EX() means the statistical expectation function with respect to X, and hRD denotes the simultaneous channel fading coefficient of the link from R to D.

Section snippets

System model

As shown in Fig. 1, we consider a decode-and-forward (DF) wireless powered relaying system, which consists of a source station, a wireless powered relay station and a destination, denoted as S, R and D, respectively. It is assumed that each station works in half duplex mode and is equipped with one single antenna due to the equipment size or the power consumption constraint. In addition, all other wireless channels are assumed to be quasi-static Rayleigh block fading [35]. hSRCN(0,α1), hRDCN(0

Outage performance analysis

In this section, we will derive the closed-form analytical expressions on the outage probability for the wireless powered relaying system, as well as the asymptotic expressions for large transmission power. Based on the analytical expressions, the effects of the system parameters are revealed.

Simulation results

In this section, simulation results are provided to verify the presented analysis. We investigate the effects of the system parameters, such as channel correlation coefficient, average channel fading power, energy harvesting coefficient and slot allocation coefficient, on the system outage probability [[42], [43], [44], [45], [46]]. In all simulation setup, we set the predefined requirement rate as Ct=1bps/Hz, and the truncation parameters are fixed as N=M=30.2

Conclusion

In this paper, we investigate outage probability of wireless powered cooperative system over correlated wireless channel, in which the better branch is selected between the relaying link and the direct links. The effect of the system parameters on outage probability is studied by deriving the closed-form analytical expressions as well as the asymptotic expressions for large transmission power. Furthermore, simulation results are provided to verify the theoretical analysis. According to the

Acknowledgments

This work was supported in part by the Science and Technology Program of Guangzhou, China, under Grant 201707010389, in part by the Scientific Research Project of Guangzhou Municipal University under Grant 1201620439, in part by the Qingshanhu Young Scholar Program in GZPYP under Grant 2016Q001, in part by Comba Research Funds under Grant JX-PYP-201501 and Grant H2017007, in part by Guangdong big data technology research center for intelligent vocational education under Grant 005 and

Dan Deng received his Bachelor and Ph.D. degrees from University of Science and Technology of China, in 2003 and 2008, respectively, both from Department of Electronic Engineering and Information Science. From 2008 to 2014, he was with Comba Telecom Ltd. in Guangzhou China, as a Director. Since 2014, he has joined Guangzhou Panyu Polytechnic, where he is currently an Associate Professor. His research interests include MIMO communication and physical-layer security in next-generation wireless

References (46)

  • LiJ. et al.

    Low complexity detection for quadrature spatial modulation systems

    Wirel. Pers. Commun.

    (2017)
  • TanW. et al.

    Spectral efficiency of DFT-based processing hybrid architectures in massive MIMO

    IEEE Wirel. Commun. Lett.

    (2017)
  • ZhaoN. et al.

    Wireless energy harvesting in interference alignment networks

    IEEE Commun. Mag.

    (2015)
  • DengD. et al.

    Joint user and relay selection for cooperative NOMA networks

    IEEE Access

    (2017)
  • GuoJ. et al.

    Exploiting adversarial jamming signals for energy harvesting in interference networks

    IEEE Trans. Wirel. Commun.

    (2017)
  • ZhaoN. et al.

    Exploiting interference for energy harvesting: A survey, research issues, and challenges

    IEEE Access

    (2017)
  • ZhaoN. et al.

    Opportunistic communications in interference alignment networks with wireless power transfer

    IEEE Wirel. Commun.

    (2015)
  • KhandakerM.R.A. et al.

    SWIPT in MISO multicasting systems

    IEEE Wirel. Commun. Lett.

    (2014)
  • LiuL. et al.

    Wireless information transfer with opportunistic energy harvesting

    IEEE Trans. Wirel. Commun.

    (2013)
  • ZhaoS. et al.

    Antenna selection for simultaneous wireless information and power transfer in MIMO systems

    IEEE Commun. Lett.

    (2014)
  • LiuG. et al.

    Energy-efficient scheduling for distributed estimation in wireless sensor and actuator networks with kriging

    Ad Hoc Sensor Wirel. Netw.

    (2015)
  • LiuG. et al.

    Channel-aware adaptive quantization method for source localization in wireless sensor networks

    Int. J. Distrib. Sensor Netw.

    (2015)
  • HuangG. et al.

    Wireless information and energy transfer in nonregenerative OFDM AF relay systems

    Wirel. Pers. Commun.

    (2017)
  • Cited by (12)

    • Impact of channel correlation on network coded cooperation with two sources

      2021, Physical Communication
      Citation Excerpt :

      Analytical expressions for cooperative diversity using selection relaying over correlated log-normal channels are discussed in [23]. In [24], authors discussed the impact of correlated channels on the wireless powered cooperative networks, where correlation between the direct link (source and destination) and the relaying link is considered. Effect of NC-noise on NCC, using AF relaying scheme in correlated Rayleigh faded channel is evaluated through simulations in [25].

    • Enhancing security in multicasting through correlated Nakagami-m fading channels with opportunistic relaying

      2020, Physical Communication
      Citation Excerpt :

      The authors of [7] considered a cooperative network without correlation, security and multicasting. The cooperative diversity in a correlated network was investigated by the authors of [9,10] neglecting security and multicasting issue. The security in a cooperative network in the presence of channel correlation was analyzed by the authors of [11–13] but multicasting issue with constant and exponential correlation was ignored.

    • Analysis of time-switching and power-splitting protocols in wireless-powered cooperative communication system

      2018, Physical Communication
      Citation Excerpt :

      The efficiency of SWIPT scheme lies on the fact that the RF signal carries both energy and information simultaneously. SWIPT enabled communication models have shown significant gains in terms of spectral efficiency and energy consumption [5–7]. In the future, SWIPT can be of fundamental importance in 5G communication for various types of modern communication systems.

    View all citing articles on Scopus

    Dan Deng received his Bachelor and Ph.D. degrees from University of Science and Technology of China, in 2003 and 2008, respectively, both from Department of Electronic Engineering and Information Science. From 2008 to 2014, he was with Comba Telecom Ltd. in Guangzhou China, as a Director. Since 2014, he has joined Guangzhou Panyu Polytechnic, where he is currently an Associate Professor. His research interests include MIMO communication and physical-layer security in next-generation wireless communication systems. He has published 29 papers in international journals and conferences. Also, he holds 19 patents, and has served as a member of Technical Program Committees for several conferences.

    Junjuan Xia received the bachelor degree from the department of computer science from Tianjin University in 2003, and obtained the master degree from the department of electronic engineering from Shantou University in 2015. Now she works for the school of Computer Science and Educational Software, Guangzhou University as a laboratory engineer. Her current research interests include wireless caching, physical-layer security, cooperative relaying and interference modeling.

    Zhenyu Na received the B.S. degree and the M.S. degree in communication engineering from the Harbin Institute of Technology, China, in 2004 and 2007, respectively, and the Ph.D. degree in information and communication engineering from the Communication Research Center, Harbin Institute of Technology, in 2010. He is currently an Associate Professor with the School of Information Science and Technology, Dalian Maritime University, China. His research interests include satellite communications and networking, OFDM, non-orthogonal multicarrier transmissions, NOMA over satellite, wireless powered communication networks.

    Junhui Zhao received the B.S. degree from Xi’an University of Technology, Xi’an, China, in 2006; the M.S. degree from Chongqing University, Chongqing, China, in 2009; and the Ph.D. degree from Wayne State University, Detroit, MI, USA, in 2014, all in electrical engineering. Since 2014, he has been an Assistant Professor in the Department of Electrical and Computer Engineering and Computer Science, University of New Haven, West Haven, CT, USA. His research interests include modeling and control of renewable/alternative energy systems, distributed generation, micro grid, and power system voltage stability.

    Qinghai Yang received his B.S. degree in Communication Engineering from Shandong University of Technology, Jinan, China in 1998, M.S. degree in Information and Communication Systems from Xidian University, China in 2001, and Ph. D. in Communication Engineering from Inha University, Korea in 2007 with university-president award. From 2007 to 2008, he was a research fellow with Ultra-wideband Wireless Communication Research Center, Inha University. Since 2008, he has been with Xidian University. His current research interests include the fields of autonomic communication, content delivery networks and LTE-A techniques.

    View full text