TRANSACTIONS ON EMERGING TELECOMMUNICATIONS TECHNOLOGIES Trans Emerging Tel Tech (2013) Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/ett.2719 RESEARCH ARTICLE Exact outage analysis of underlay cooperative cognitive networks with maximum transmit-and-interference power constraints and erroneous channel information Khuong Ho-Van* HoChiMinh City University of Technology, 268 Ly Thuong Kiet street, District 10, HoChiMinh City, Vietnam ABSTRACT This paper presents exact analysis of interference probability and outage probability of underlay cooperative cognitive networks under quite general conditions such as imperfect channel information, maximum transmit-and-interference power constraints, correlation among received signal-to-noise ratios and non identically distributed fading channels In addition, asymptotic outage analysis at either large maximum transmit power or large maximum interference power is proposed to have useful insights into performance limits of underlay cooperative cognitive networks Analytical results reveal that underlay cooperative cognitive networks dramatically suffer outage saturation phenomenon, and saturation degree significantly depends on channel estimation quality Moreover, the performance of both licenced network in terms of interference probability and unlicenced network in terms of outage probability is considerably deteriorated by channel estimation error Furthermore, optimum relay position is dependent of several factors such as maximum transmit power, maximum interference power, licensee position and channel estimation quality Copyright © 2013 John Wiley & Sons, Ltd *Correspondence Khuong Ho-Van, HoChiMinh City University of Technology, 268 Ly Thuong Kiet street, District 10, HoChiMinh City, Vietnam E-mail: khuong.hovan@yahoo.ca Received 28 June 2013; Revised 11 August 2013; Accepted September 2013 INTRODUCTION Underlay decode-and-forward (DF* ) cooperative† cognitive network is a feasible-and-efficient solution to problems of spectrum scarcity, spectrum under-utilisation and coverage extension [1–4] For system design optimization such as power allocation optimization, channel information must be available However, it is almost impossibly expected to have full knowledge of channel information from existing channel estimation algorithms As such, the investigation on the impact of imperfect channel information on the system performance is necessary On the other hand, outage probability is a useful metric in providing insights into the information-theoretic * Popularly, the relay in most cooperative relaying schemes operates in either DF or amplify-and-forward type [33, 34] † Multi-hop communication (e.g [2], [6]) differs from cooperative relaying (e.g [7, 8]) in that the former bypasses the direct channel between the source and the destination while for enhanced space diversity, the latter does Copyright © 2013 John Wiley & Sons, Ltd performance limit [5] As a result, a general outage analysis framework for underlay DF cooperative cognitive networks, accounting for multiple practical operation conditions such as imperfect channel information on all channels, two maximum transmit-and-interference power constraints, non-identically distributed (i.d.) fading channels and the correlation among received signal-to-noise ratios (SNRs) is urgent and essential Nevertheless, current publications have not considered all these conditions concurrently For instances, the authors in [2–4, 6–8], [9–32] partially investigated them More specifically, the authors in [3, 7, 8], [16–20], [22–25] analysed the outage performance of underlay DF cooperative cognitive networks‡ in different aspects under the assumption of perfect channel information: (i) about ‡ This paper studies underlay DF cooperative cognitive networks, and hence, the works on other modes (e.g the interweave mode in [31]), error probability analysis (e.g [4], [27–30]), the amplify-and-forward type (e.g [14, 32]), and multi-hop communications (e.g [2, à s N v  à r F1 tF 2IT SL 2Pt 1C e I0 rF 1 ÁO SL ÁSL SL / Pt 0s N s C r/ N I T 4e A F2 D e Q@ 2Pt 0s s sF C rF / N0 v A tF @ sF rF / N0 v Q ; C rF 2Pt 2Pt  à s N v  à F2 tF IT p 2Pt 1C e I0 sN rN 2 rF 2Pt ˛SR ˇSR v (72) ˛SR N0 v Pt Trans Emerging Tel Tech (2013) © 2013 John Wiley & Sons, Ltd DOI: 10.1002/ett Ns r/ N IT ; 2Pt (73) s (74) K Ho-Van Meanwhile, with the aid of [45, Equation (24)], the F3 term is represented in closed form as F3 D 2Q uF ; vF / sF ˛SR N0 v sI N C 2PT Pt t e sF 2IT  I0 where IT sF D N0 v s Á (75) r SL / Pt ˛SR N0 v sN C IT Ã2 SL à ÁO SL ÁSL SL ÁO SL ÁSL / SL / (76) s uF D s vF D N0 v Pt N0 v Pt  à ˛SR C sN IT 2N0 v ˛SR C sN IT C sF 2N0 v  sF (77) à (78) By plugging Equations (60), (65) and (66) into Equation (59), one achieves the closed form of W ACKNOWLEDGEMENTS This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 102.04-2012.39 REFERENCES Goldsmith A, Jafar SA, Maric I, Srinivasa S Breaking spectrum gridlock with cognitive radios: an information theoretic perspective Proceedings of the IEEE 2009; 97(5): 894–914 Lee J, Wang H, Andrews JG, Hong D Outage probability of cognitive relay networks with interference constraints IEEE Transactions on Wireless Communications 2011; 10(2): 390–395 Hong JP, Hong B, Ban TW, Choi W On the cooperative diversity gain in underlay cognitive radio systems IEEE Transactions on Communications 2012; 60(1): 209–219 Ho-Van K, Bao VNQ Symbol error rate of underlay cognitive relay systems over Rayleigh fading channel IEICE Transactions on Communications 2012; E95–B(5): 1873–1877 Ozarow L, Shamai S, Wyner A Information theoretic considerations for cellular mobile radio IEEE Transactions on Vehicular Technology 1994; 43(2): 359–378 Zhong C, Ratnarajah T, Wong K-K Outage analysis of decode-and-forward cognitive dual-hop systems with the interference constraint in Nakagami-m fading channels IEEE Transactions on Vehicular Technology 2011; 60(6): 2875–2879 Yan Z, Zhang X, Wang W Exact outage performance of cognitive relay networks with maximum transmit power limits IEEE Communications Letters 2011; 15(12): 1317–1319 Guo Y, Kang G, Zhang N, Zhou W, Zhang P Outage performance of relay-assisted cognitive-radio system under spectrum-sharing constraints Electronics Letters 2010; 46(2): 182–184 Si J, Li Z, Huang H, Chen J, Gao R Capacity analysis of cognitive relay networks with the PU’s interference IEEE Communications Letters 2012; 16(12): 2020–2023 10 Xu W, Zhang J, Zhan P, Tellambura C Outage probability of decode-and-forward cognitive relay in presence of primary user’s interference IEEE Communications Letters 2012; 16(8): 1252–1255 11 Duong TQ, Yeoh PL, Bao VNQ, Elkashlan M, Yang N Cognitive relay networks with multiple primary transceivers under spectrum-sharing IEEE Signal Processing Letters 2012; 19(11): 741–744 12 Wang J, Zhang Z, Wu Q, Huang Y Outage analysis of cognitive relay networks with interference constraints in Nakagami-m channels IEEE Wireless Communications Letters 2013; 2(4): 387–390 13 Ding H, Ge J, Benevides da Costa D, Jiang Z Asymptotic analysis of cooperative diversity systems with relay selection in a spectrum-sharing scenario IEEE Transactions on Vehicular Technology 2011; 60(2): 457–472 14 Chen J, Si J, Li Z, Huang H On the performance of spectrum sharing cognitive relay networks with imperfect CSI IEEE Communications Letters 2012; 16(7): 1002–1005 15 Bao VNQ, Duong TQ Outage analysis of cognitive multihop networks under interference constraints IEICE Transactions on Communications 2012; E95-B(03): 1019–1022 16 Liping L, Zhang P, Zhang G, Qin J Outage performance for cognitive relay networks with underlay spectrum sharing IEEE Communications Letters 2011; 15(7): 710–712 17 Ho-Van K Exact outage probability of underlay cognitive cooperative networks over Rayleigh fading channels Wireless Personal Communications 2013; 70(2): 1001–1009 18 Duong TQ, da Costa DB, Tsiftsis TA, Zhong C, Nallanathan A Outage and diversity of cognitive relaying systems under spectrum sharing environments in Trans Emerging Tel Tech (2013) © 2013 John Wiley & Sons, Ltd DOI: 10.1002/ett K Ho-Van 19 20 21 22 23 24 25 26 27 28 29 30 Nakagami-m fading IEEE Communications Letters 2012; 16(12): 2075–2078 Yang P, Liping L, Jiayin Q Outage performance of cognitive relay networks with interference from primary user IEEE Communications Letters 2012; 16(10): 1695–1698 Zou Y, Yao YD, Zheng B Cooperative relay techniques for cognitive radio systems: spectrum sensing and secondary user transmissions IEEE Communications Magazine 2012; 50(4): 98–103 Bao VNQ, Duong TQ Exact outage probability of cognitive underlay DF relay networks with best relay selection IEICE Transactions on Communications 2012; E95–B(06): 2169–2173 Duy TT, Bao VNQ Outage performance of cooperative multihop transmission in cognitive underlay networks, In Proc The International Conference on Computing, Management and Telecommunications, HCM City, Vietnam, 2013; 123–127 Li D Cognitive relay networks: opportunistic or uncoded decode-and-forward relaying? IEEE Transactions on Vehicular Technology Accepted Zhang X, Yan Z, Gao Y, Wang W On the study of outage performance for cognitive relay networks (CRN) with the N t h best-relay selection in Rayleigh-fading channels IEEE Wireless Communications Letters 2013; 2(1): 110–113 Tourki K, Qaraqe KA, Alouini MS Outage analysis for underlay cognitive networks using incremental regenerative relaying IEEE Transactions on Vehicular Technology 2013; 62(2): 721–734 Zhang X, Xing J, Yan Z, Gao Y, Wang W Outage performance study of cognitive relay networks with imperfect channel knowledge IEEE Communications Letters 2013; 17(1): 27–30 Hussain SL, Abdallah MM, Alouini MS, Hasna M, Qaraqe K Performance analysis of selective cooperation in underlay cognitive networks over Rayleigh channels, In Proc IEEE Inernational Workshop on Signal Processing Advances in Wireless Communications, San Francisco, California, USA, 2011; 116–120 Do T, Mark N Cooperative communication with regenerative relays for cognitive radio networks, In Proc 44th Annual Conference in Information Sciences and Systems, Princeton, NJ, USA, 2010; 1–6 Ho-Van K Performance evaluation of underlay cognitive multi-hop networks over Nakagami-m fading channels Wireless Personal Communications 2013; 70(1): 227–238 Yu H, Tang W, Li S Outage probability and SER of amplify-and-forward cognitive relay networks IEEE Wireless Communications Letters 2013; 2(2): 219–222 Trans Emerging Tel Tech (2013) © 2013 John Wiley & Sons, Ltd DOI: 10.1002/ett 31 Kim J, Kim D Outage probability and achievable diversity order of opportunistic relaying in cognitive secondary radio networks IEEE Transactions on Communications 2012; 60(9): 2456–2466 32 Xia M, Aissa S Cooperative AF relaying in spectrumsharing systems: outage probability analysis under cochannel interferences and relay selection IEEE Transactions on Communications 2012; 60(11): 3252–3262 33 Laneman JN, Tse DNC, Wornell GW Cooperative diversity in wireless networks: efficient protocols and outage behavior IEEE Transactions on Information Theory 2004; 50(12): 3062–3080 34 Nosratinia A, Hunter T A Hedayat Cooperative communication in wireless networks IEEE Communications Magazine 2004; 42(10): 74–80 35 Ahmed N, Khojastepour M, Aazhang B Outage minimization and optimal power control for the fading relay channel, In Proc IEEE Information Theory Workshop, San Antonio, TX, USA, 2004; 458–462 36 Athanasios P, Pillai SU Probability, Random Variables and Stochastic Process, 4th ed McGraw Hill: New York, USA, 2002 37 Amin O, Ikki SS, Uysal M On the performance analysis of multirelay cooperative diversity systems with channel estimation errors IEEE Transactions on Vehicular Technology 2011; 60(5): 2050–2059 38 Han S, Ahn S, Oh E, Hong D Effect of channelestimation error on BER performance in cooperative transmission IEEE Transactions on Vehicular Technology 2009; 58(4): 2083–2088 39 Yi W, Patzold M Performance analysis of cooperative communication systems with imperfect channel estimation, In Proc IEEE ICC, Dresden, Germany, June 14; 1–6 40 Patel CS, Stuber GL Channel estimation for amplify and forward relay based cooperation diversity systems IEEE Transactions on Wireless Communications 2007; 6(6): 2348–2356 41 Suraweera HA, Smith PJ, Shafi M Capacity limits and performance analysis of cognitive radio with imperfect channel knowledge IEEE Transactions on Vehicular Technology 2010; 59: 1811–1822 42 Gradshteyn IS, Ryzhik IM Table of Integrals, Series and Products, 6th ed Academic Press: San Diego, CA, 2000 43 Tellambura C, Jayalath ADS Generation of bivariate Rayleigh and Nakagami-m fading envelopes IEEE Communications Letters 2000; 4: 170–172 44 Proakis JG Digital Communications, 3rd ed McGrawHill: Singapore, 1995 45 Nuttall AH Some integrals involving the Q-function Tech Rep 4297, Naval Underwater Syst Cent., New London, CT, 1972  ... gridlock with cognitive radios: an information theoretic perspective Proceedings of the IEEE 2009; 97(5): 894–914 Lee J, Wang H, Andrews JG, Hong D Outage probability of cognitive relay networks with. .. IEEE Communications Letters 2011; 15(7): 710–712 17 Ho-Van K Exact outage probability of underlay cognitive cooperative networks over Rayleigh fading channels Wireless Personal Communications 2013;... evaluation of underlay cognitive multi-hop networks over Nakagami-m fading channels Wireless Personal Communications 2013; 70(1): 227–238 Yu H, Tang W, Li S Outage probability and SER of amplify -and- forward