Performance analysis of coded secondary relaying in overlay cognitive radio networks
01 Apr 2012-pp 294-299
TL;DR: The error and diversity-multiplexing tradeoff performance of a (secondary) multi-user relay network, where a class of finite field network codes are applied in the relays to efficiently provide spatial diversity, is studied.
Abstract: We study the error and diversity-multiplexing tradeoff (DMT) performance of a (secondary) multi-user relay network, where a class of finite field network codes are applied in the relays to efficiently provide spatial diversity To eliminate spectral efficiency loss induced by half-duplex limitation we adopt the cognitive radio overlay spectrum sharing concept and consider aligning the relays' operation with that of a primary system To compensate the interference introduced by the secondary relaying, the secondary destination also transmits the primary signals to boost the signal power of the primary system We also consider exploiting Automatic Repeat Request (ARQ) feedback signals from the secondary destination to minimize the energy consumption of the secondary system In addition, by allowing multiple secondary sources to transmit non-orthogonally, the performance can be further enhanced
Citations
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TL;DR: A comprehensive survey of NC schemes in cognitive radio networks is provided, highlighting the motivations for and the applications of NC in CRNs.
Abstract: Network coding (NC) is a technique used for effective and secure communication by improving the network capacity, throughput, efficiency, and robustness. In NC, data packets are encoded by intermediate nodes and are then decoded at the destination nodes. NC has been successfully applied in a variety of networks including relay networks, peer-to-peer networks, wireless networks, cognitive radio networks, and wireless sensor networks. Cognitive radio network (CRN) is an emerging field which exploits the utilization of unused spectrum or white spaces, effectively and efficiently. In CRNs, NC schemes are also applied to maximize the spectrum utilization, as well as to maintain the effective and secure transmission of data packets over the network. In this paper, we provide a comprehensive survey of NC schemes in cognitive radio networks, highlighting the motivations for and the applications of NC in CRNs. We provide typical case studies of NC schemes in CRNs, as well as the taxonomy of NC schemes in CRNs. Finally, we present open issues, challenges, and future research directions related with NC in cognitive radio networks.
76 citations
Cites methods from "Performance analysis of coded secon..."
...By applying coding strategy on relay networks, communication between source and destination nodes becomes efficient and effective [154]....
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TL;DR: This article presents a detailed investigation and comparison of current state-of-the-art protocols and algorithms for Network Coding in Cognitive Radio Networks (CRNs) and discusses five illustrative examples of network coding.
66 citations
Cites background or methods from "Performance analysis of coded secon..."
...MPEG-4 Streaming (Shrimali and Narmawala, 2012; Phycom editorial, 2013; Wang et al., 2012a): MPEG-4 streaming over wireless networks can be improved using Random Linear Network Coding with Multi Generation Mixing (MGM)....
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...…rate and still maintain the benefits of diversity PER performance – – Chaoub and IbnElhaj (2012) Multiple descriptor coding Deal with dynamics between primary and secondary users Spectral Efficiency – – Wang et al. (2012b) Secondary relaying To eliminate spectral efficiency loss induced by…...
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...…Rahnavard (2011), Khomyat et al. (2011) Zhang et al. (2012), Tang and Liu (2012), Shu et al. (2012), Xu et al. (2012), Chaoub and IbnElhaj (2012), Wang et al. (2012b), Stupia et al. (2012), Zheng et al. (2012), Yang et al. (2012), Abrol and Sharma (2012) Xie and Wang (2013), Yang and Aissa…...
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01 Feb 2017
TL;DR: It is shown through theoretical and numerical results that cooperative communication with network coding can provide significant gains in terms of outage probability and diversity order when compared with non‐cooperative or traditional cooperative.
Abstract: We evaluate the performance of a network-coded cooperative secondary network in a cognitive radio system under spectrum sharing constraints. The secondary network is composed of multiple sources that cooperate to transmit their own information to a common secondary destination. The outage probability is analysed under a given maximum interference constraint set by the primary network as well as to the maximum transmit power limit of the secondary sources. Moreover, we also obtain a closed-form equation for the ϵ-outage capacity, that is, the maximum information rate achieved by the secondary sources given a target outage probability. Also, we resort to the Dinkelbach algorithm in order to find the optimum number of parity packets that maximises the ϵ-outage capacity. The influence of the number of source nodes and another system parameters in the secondary's performance is also evaluated, and we show through theoretical and numerical results that cooperative communication with network coding can provide significant gains in terms of outage probability and diversity order when compared with non-cooperative or traditional cooperative. Copyright © 2015 John Wiley & Sons, Ltd.
11 citations
Cites background from "Performance analysis of coded secon..."
...In an underlay cognitive network (CN), unlicensed users [or secondary users (SUs)] are able to utilise the same spectrum band allocated to the licensed users [or primary users (PUs)], as long as the interference imposed to the PUs remains below a given threshold....
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...Next, investigating power allocation strategies to increase the throughput of the SUs, the authors in [7] evaluate a multi-hop CN disposed in a line topology with multiple PUs....
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...(2) Moreover, we denote by ˇ the maximum amount of peak interference tolerated by Dp, such that the transmit power of Um is limited by Pm 6 min Pmax, ˇ jhmpj2 (3) where Pmax corresponds to the maximum transmit power (assumed to be the same for all SUs)....
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...Moreover, we assume a maximum transmit power constraint at the SUs of Pmax D 20 dB....
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...We consider a cognitive network composed of M SUs Um, m 2 f1, : : : , Mg, a common secondary destination Ds, a primary transmitter Tp and a primary destination Dp, as illustrated in Figure 1 for the particular case of M D 2 SUs....
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25 Nov 2013
TL;DR: New Sub-channel selection schemes which adapt either the transmission power or the sequential order of selection to enhance the system performances are proposed which will help improving the CR network performances under PU limitation.
Abstract: Cognitive Radio is a promising concept that offers solution to spectral crowding problem by introducing opportunistic usage of the unoccupied licensed frequency bands. Improving the network capacity and reliability of the communication has been recently studied and this through the introduction of cooperative technology in the CR networks. Furthermore, OFDM system is considered to be a good candidate to enhance the flexibility of the CR network, where individual carriers can be switched off for occupied frequencies by the primary user (PU) or for interfering Sub-channels. In this paper, an underlay cognitive network based on OFDM technique is proposed where secondary users (SUs) coexisting with a PU are adhering to stringent interference threshold constraint. Cooperative technology will help improving the CR network performances under PU limitation. This paper proposes new Sub-channel selection schemes which adapt either the transmission power or the sequential order of selection to enhance the system performances. We first provide the exact probability density function (PDF) of the received SNR at the secondary destination. Then, the PDFs are used to derive closed form expressions of the outage probability, the average BER and the ergodic capacity. Analytic results are validated by simulation for the proposed Sub-channels selection schemes.
9 citations
Cites background from "Performance analysis of coded secon..."
...In overlay approach [3], [4], the spectrum band is shared between PU and SUs while SUs try to improve the transmission of the PU....
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Dissertation•
01 Mar 2014
TL;DR: This thesis focuses on the real-time packet level QoS (packet delay and loss) performance of Cognitive Radio networks, and evaluates the effects on QoS of several typical non-configurable factors including secondary user service types, primary user activity patterns and user distance from base station.
Abstract: Rapid development of devices and applications results in dramatic growth of wireless traffic, which leads to increasing demand on wireless spectrum resources. Current spectrum resource allocation policy causes low efficiency in licensed spectrum bands. Cognitive Radio techniques are a promising solution to the problem of spectrum scarcity and low spectrum utilisation. Especially, OFDM based Cognitive Radio has received much research interest due to its flexibility in enabling dynamic resource allocation. Extensive research has shown how to optimise Cognitive Radio networks in many ways, but there has been little consideration of the real-time packet level performance of the network. In such a situation, the Quality of Service metrics of the Secondary Network are difficult to guarantee due to fluctuating resource availability; nevertheless QoS metric evaluation is actually a very important factor for the success of Cognitive Radio. Quality of Experience is also gaining interest due to its focus on the users’ perceived quality, and this opens up a new perspective on evaluating and improving wireless networks performance. The main contributions of this thesis include: it focuses on the real-time packet level QoS (packet delay and loss) performance of Cognitive Radio networks, and evaluates the effects on QoS of several typical non-configurable factors including secondary user service types, primary user activity patterns and user distance from base station. Furthermore, the evaluation results are unified and represented using QoE through existing mapping techniques. Based on the QoE evaluation, a novel cross layer RA scheme is proposed to dynamically compensate user experience, and this is shown to significantly improve QoE in scenarios where traditional RA schemes fail to provide good user experience. Author’s Publications B. Zhong, J. Schormans, and E. Bodanese, Evaluating QoE in Cognitive Radio Networks for Improved Network and User Performance, Communications Letters, IEEE, vol. 17, no. 12, pp. 23762379, December 2013. B. Zhong, J. Schormans, and E. Bodanese, QoE Aided Performance Compensation for Cognitive Radio Networks, Transaction on Wireless Communications, IEEE, submitted and under review.
3 citations
Cites methods from "Performance analysis of coded secon..."
...For the overlay mode [19, 20, 21], the SUs can transmit simultaneously with PUs, while the SUs helps to relay the PUs message to compensate for the interference caused to the PUs....
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References
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TL;DR: Using distributed antennas, this work develops and analyzes low-complexity cooperative diversity protocols that combat fading induced by multipath propagation in wireless networks and develops performance characterizations in terms of outage events and associated outage probabilities, which measure robustness of the transmissions to fading.
Abstract: We develop and analyze low-complexity cooperative diversity protocols that combat fading induced by multipath propagation in wireless networks. The underlying techniques exploit space diversity available through cooperating terminals' relaying signals for one another. We outline several strategies employed by the cooperating radios, including fixed relaying schemes such as amplify-and-forward and decode-and-forward, selection relaying schemes that adapt based upon channel measurements between the cooperating terminals, and incremental relaying schemes that adapt based upon limited feedback from the destination terminal. We develop performance characterizations in terms of outage events and associated outage probabilities, which measure robustness of the transmissions to fading, focusing on the high signal-to-noise ratio (SNR) regime. Except for fixed decode-and-forward, all of our cooperative diversity protocols are efficient in the sense that they achieve full diversity (i.e., second-order diversity in the case of two terminals), and, moreover, are close to optimum (within 1.5 dB) in certain regimes. Thus, using distributed antennas, we can provide the powerful benefits of space diversity without need for physical arrays, though at a loss of spectral efficiency due to half-duplex operation and possibly at the cost of additional receive hardware. Applicable to any wireless setting, including cellular or ad hoc networks-wherever space constraints preclude the use of physical arrays-the performance characterizations reveal that large power or energy savings result from the use of these protocols.
12,761 citations
"Performance analysis of coded secon..." refers background or methods in this paper
...We consider exploiting limited Automatic 978-1-4673-0437-5/12/$31.00 ©2012 IEEE 294 Repeat Request (ARQ) feedback signals from the secondary destination to avoid unnecessary relay activations [1], [3]....
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...…processing complexity: Simple schemes tend to orthogonalize source and relay operations so that extra time/frequency channels are demanded for relaying (e.g. [1]–[3]), while permitting non-orthogonal operations (e.g. [4]–[6]) in general leads to a high burden on complex encoding/decoding…...
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TL;DR: A simple characterization of the optimal tradeoff curve is given and used to evaluate the performance of existing multiple antenna schemes for the richly scattered Rayleigh-fading channel.
Abstract: Multiple antennas can be used for increasing the amount of diversity or the number of degrees of freedom in wireless communication systems. We propose the point of view that both types of gains can be simultaneously obtained for a given multiple-antenna channel, but there is a fundamental tradeoff between how much of each any coding scheme can get. For the richly scattered Rayleigh-fading channel, we give a simple characterization of the optimal tradeoff curve and use it to evaluate the performance of existing multiple antenna schemes.
4,422 citations
TL;DR: This work develops and analyzes space-time coded cooperative diversity protocols for combating multipath fading across multiple protocol layers in a wireless network and demonstrates that these protocols achieve full spatial diversity in the number of cooperating terminals, not just theNumber of decoding relays, and can be used effectively for higher spectral efficiencies than repetition-based schemes.
Abstract: We develop and analyze space-time coded cooperative diversity protocols for combating multipath fading across multiple protocol layers in a wireless network. The protocols exploit spatial diversity available among a collection of distributed terminals that relay messages for one another in such a manner that the destination terminal can average the fading, even though it is unknown a priori which terminals will be involved. In particular, a source initiates transmission to its destination, and many relays potentially receive the transmission. Those terminals that can fully decode the transmission utilize a space-time code to cooperatively relay to the destination. We demonstrate that these protocols achieve full spatial diversity in the number of cooperating terminals, not just the number of decoding relays, and can be used effectively for higher spectral efficiencies than repetition-based schemes. We discuss issues related to space-time code design for these protocols, emphasizing codes that readily allow for appealing distributed versions.
4,385 citations
"Performance analysis of coded secon..." refers background in this paper
...The conventional repetition-coded relaying protocol [2] demands M(K + 1) time-division-multiple-access (TDMA) time slots (or frequency-division-multiple-access, FDMA, frequency slots) to deliver one message from each source: Each source uses one slot to broadcast its message, and each relay uses M slots to retransmit the M source messages respectively to provide spatial diversity....
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24 Apr 2009
TL;DR: This information-theoretic survey provides guidelines for the spectral efficiency gains possible through cognitive radios, as well as practical design ideas to mitigate the coexistence challenges in today's crowded spectrum.
Abstract: Cognitive radios hold tremendous promise for increasing spectral efficiency in wireless systems. This paper surveys the fundamental capacity limits and associated transmission techniques for different wireless network design paradigms based on this promising technology. These paradigms are unified by the definition of a cognitive radio as an intelligent wireless communication device that exploits side information about its environment to improve spectrum utilization. This side information typically comprises knowledge about the activity, channels, codebooks, and/or messages of other nodes with which the cognitive node shares the spectrum. Based on the nature of the available side information as well as a priori rules about spectrum usage, cognitive radio systems seek to underlay, overlay, or interweave the cognitive radios' signals with the transmissions of noncognitive nodes. We provide a comprehensive summary of the known capacity characterizations in terms of upper and lower bounds for each of these three approaches. The increase in system degrees of freedom obtained through cognitive radios is also illuminated. This information-theoretic survey provides guidelines for the spectral efficiency gains possible through cognitive radios, as well as practical design ideas to mitigate the coexistence challenges in today's crowded spectrum.
2,516 citations
"Performance analysis of coded secon..." refers methods in this paper
...To handle this issue, we consider adopting the cognitive radio overlay spectrum sharing concept [10], [11] so that the relays may operate in the spectrum band (or time duration) owned by another system (e.g. a TV broadcasting system)....
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TL;DR: Two new half-duplex relaying protocols are proposed that avoid the pre-log factor one-half in corresponding capacity expressions and it is shown that both protocols recover a significant portion of the half- duplex loss.
Abstract: We study two-hop communication protocols where one or several relay terminals assist in the communication between two or more terminals. All terminals operate in half-duplex mode, hence the transmission of one information symbol from the source terminal to the destination terminal occupies two channel uses. This leads to a loss in spectral efficiency due to the pre-log factor one-half in corresponding capacity expressions. We propose two new half-duplex relaying protocols that avoid the pre-log factor one-half. Firstly, we consider a relaying protocol where a bidirectional connection between two terminals is established via one amplify-and-forward (AF) or decode-and-forward (DF) relay (two-way relaying). We also extend this protocol to a multi-user scenario, where multiple terminals communicate with multiple partner terminals via several orthogonalize-and-forward (OF) relay terminals, i.e., the relays orthogonalize the different two-way transmissions by a distributed zero-forcing algorithm. Secondly, we propose a relaying protocol where two relays, either AF or DF, alternately forward messages from a source terminal to a destination terminal (two-path relaying). It is shown that both protocols recover a significant portion of the half-duplex loss
1,728 citations