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Optimal power allocation for cognitive relay networks: amplify-and-forward versus selection relay

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Abstract

We consider a cognitive relay network which is defined by a source, a destination, and cognitive relay nodes and primary user nodes. In this network, a source is assisted by cognitive relay nodes which allow coexisting with primary user nodes by imposing severe constraints on the transmission power so that they operate below the noise floor of primary user nodes. In this paper, we mainly study the power allocation strategies of this system to minimize the outage probability subject to total and individual power constraints for cognitive relay nodes and subject to interference constraints for primary user nodes. A relay transmission scheme, namely amplify-and-forward (AF), is considered. We first present an optimal power allocation (OPA) scheme to minimize the system outage probability, based on instantaneous channel state information among the source, destination and relay nodes and mean channel gains between primary user nodes and cognitive relays. Next, we propose a selection AF scheme (S-AF) where the single best relay is chosen to assist in the transmission and study power allocation strategy for S-AF to minimize outage probability. The analytical power allocation strategies have been validated through numerical simulations. The results indicate that the AF with OPA and S-AF with OPA have significantly better outage behavior and average throughput than AF and S-AF schemes respectively. We also find that S-AF with OPA achieves a higher throughput, and hence lower outage probability than AF with OPA.

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References

  1. Federal Communications Commission. Spectrum Policy Task Force. Rep. ET Docket no. 02-135, Nov. 2002

  2. Mitola J, Maguire G Q. Cognitive radio: making software radios more personal. IEEE Pers Commun, 1999, 6: 13–18

    Article  Google Scholar 

  3. Zhao Q, Sadler B M. A survey of dynamic spectrum access. IEEE Signal Process Mag, 2007, 24: 79–89

    Article  Google Scholar 

  4. Laneman J N, Wornell G W. Distributed space-time-coded protocols for exploiting cooperative diversity in wireless networks. IEEE Trans Inf Theory, 2003, 49: 2415–2425

    Article  MathSciNet  Google Scholar 

  5. Zhao R, Yang L X, Zhu W P. Transmission scheme and performance analysis for decode-and-forward MIMO two-way relay systems. Sci China Ser F-Inf Sci, 2009, 52: 2308–2316

    Article  MATH  Google Scholar 

  6. Laneman J N, Wornell G W. Cooperative diversity in wireless networks: efficient protocols and outage behavior. IEEE Trans Inf Theory, 2004, 50: 3062–3080

    Article  MathSciNet  Google Scholar 

  7. Zhang Y, Xu Y Y, Cai Y M. Power allocation for non-orthogonal decode-and-forward cooperation protocol. Sci China Ser F-Inf Sci, 2009, 52: 1037–1042

    Article  MATH  Google Scholar 

  8. Zhao Y, Advee R, Lim T J. Improving amplify-and-forward relay networks: optimal power allocation versus selection. IEEE Trans Wirel Commun, 2007, 6: 3114–3123

    Google Scholar 

  9. Lee K, Yener A. Outage performance of cognitive wireless relay networks. In: Proc. IEEE GLOBECOM, San Francisco, CA, 2006. 1–5

  10. Suraweera H A, Smith P J, Surobhi N A. Exact outage probability of cooperative diversity with opportunistic spectrum access. In: Proc. IEEE Int. Conf. on Commun. (ICC’08), Beijing, 2008. 79–84

  11. Fujii T, Suzuki Y. Ad-hoc cognitive radio-development to frequency sharing system by using multi-hop network. In: Proc. IEEE DySPAN 2005, Maryland, MD, 2005. 589–592

  12. Hasna M Q, Alouini M S. End-to-end performance of transmission systems with relays over Rayleigh fading channel. IEEE Trans Wirel Commun, 2003, 2: 1126–1131

    Article  Google Scholar 

  13. Seddik K G, Sadek A K, Su W, et al. Outage analysis and optimal power allocation for multimode relay networks. IEEE Signal Process Lett, 2007, 14: 377–380

    Article  Google Scholar 

  14. Boyd S, Vandenberghe L. Convex Optimization. Cambridge, UK: Cambridge University Press, 2004

    MATH  Google Scholar 

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Authors and Affiliations

  1. Institute of Signal Processing and Transmission, Nanjing University of Posts and Telecommunications, Nanjing, 210003, China

    WenJing Yue, BaoYu Zheng, QingMin Meng & JingWu Cui

  2. Department of Electronic Engineering, Shanghai Jiaotong University, Shanghai, 200240, China

    WenJing Yue & BaoYu Zheng

  3. Shanxi Institute of Educational Science, Taiyuan, 030009, China

    WenJie Yue

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  1. WenJing Yue
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  2. BaoYu Zheng
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  3. QingMin Meng
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  4. WenJie Yue
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  5. JingWu Cui
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Correspondence to WenJing Yue.

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Yue, W., Zheng, B., Meng, Q. et al. Optimal power allocation for cognitive relay networks: amplify-and-forward versus selection relay. Sci. China Inf. Sci. 54, 861–872 (2011). https://doi.org/10.1007/s11432-010-4156-9

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  • DOI: https://doi.org/10.1007/s11432-010-4156-9

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