Cognitive Transmissions with Multiple Relays in Cognitive Radio Networks

Zou, Yulong; Yao, Yu-Dong; Zheng, Baoyu

doi:10.1109/twc.2010.120610.100830

Cited by 117 publications

(91 citation statements)

References 23 publications

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“…In this section, we conduct numerical outage probability evaluations for the traditional SFSS-BRDT scheme (with a dedicated channel) [5] and the proposed SRSS-BRDT scheme (without a dedicated channel). Notice that, in the following numerical evaluations, the fading variances of the channel between each sender-receiver within a same network (primary or secondary networks) and that across different networks are specified to 1 and 0.5, respectively.…”

Section: Numerical Results and Analysismentioning

confidence: 99%

“…As discussed in [3]- [5], each cognitive transmission process requires two essential phases: 1) a spectrum sensing phase, in which a cognitive source attempts to detect an available spectrum hole; and 2) a data transmission phase, in which secondary data traffic (of the cognitive source) is transmitted to the destination through the detected spectrum hole. The two individual phases have been studied extensively in terms of different sensing [6]- [12] or different transmission [13]- [19] techniques.…”

Section: Introductionmentioning

confidence: 99%

“…However,asmentioned in [3]- [5], the spectrumsensing anddata transmission phases can not be designed and optimized in isolation since the two phases affect each other. In [3], the authors focus on the maximization of secondary throughput under the constraint of primary user protection over additive white Gaussian noise (AWGN) channels.…”

Section: Introductionmentioning

confidence: 99%

“…In [4], we have explored the sensing-and-transmission tradeoff issue over Rayleigh fading channels and shown that the outage probability of cog- nitive transmissions can be minimized through the optimization of spectrum sensing overhead. Furthermore, we have investigated the cognitive transmissions with multiple relays in [5], where multiple cognitive relays are available to assist a cognitive source for both the spectrum sensing and data transmissions. In [5], we first propose a fixed fusion spectrum sensing and best relay data transmission (FFSS-BRDT) scheme and show that, as the number of cognitive relays increases, the performance of the FFSS-BRDT scheme improves initially and then begins to degrade when the number of cognitive relays is largerthan a certain value.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, we have investigated the cognitive transmissions with multiple relays in [5], where multiple cognitive relays are available to assist a cognitive source for both the spectrum sensing and data transmissions. In [5], we first propose a fixed fusion spectrum sensing and best relay data transmission (FFSS-BRDT) scheme and show that, as the number of cognitive relays increases, the performance of the FFSS-BRDT scheme improves initially and then begins to degrade when the number of cognitive relays is largerthan a certain value. We then propose a selective fusion spectrum sensing and best relay data transmission (SFSS-BRDT) scheme, which performs better than FFSS-BRDT scheme.…”

Section: Introductionmentioning

confidence: 99%

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A Cooperative Sensing Based Cognitive Relay Transmission Scheme Without a Dedicated Sensing Relay Channel in Cognitive Radio Networks

Zou

Yao

Zheng

2011

IEEE Trans. Signal Process.

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Abstract-In this correspondence, we investigate a selective relay spectrum sensing and best relay data transmission (SRSS-BRDT) scheme for multiple-relay cognitive radio networks. Specifically, in the spectrum sensing phase, only selected cognitive relays are utilized to transmit/forward their initial detection results (without a dedicated sensing relay channel) to a cognitive source for fusion, where the dedicated sensing channel refers to the channel transmitting initial spectrum sensing results from cognitive relays to the cognitive source. In the data transmission phase, only the best relay is selected to assist the cognitive source for its data transmissions. By jointly considering the two phases, we derive a closed-form expression of the outage probability for the SRSS-BRDT scheme over Rayleigh fading channels. We show that the SRSS-BRDT scheme outperforms the traditional cognitive transmission scheme (with a limited dedicated sensing channel) in terms of the outage probability performance. In addition, numerical results illustrate that the outage probability of the SRSS-BRDT scheme can be minimized through an optimal allocation of the time durations between the spectrum sensing and data transmission phases.

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Section: Numerical Results and Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A Cooperative Sensing Based Cognitive Relay Transmission Scheme Without a Dedicated Sensing Relay Channel in Cognitive Radio Networks

Zou

Yao

Zheng

2011

IEEE Trans. Signal Process.

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Efficient secondary access with intelligent spectrum sensing in cognitive radio networks

Dai

Liu

Sun³

et al. 2013

Int J Communication

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SUMMARYIn cognitive radio networks, cooperative sensing can significantly improve the performance in detection of a primary user via secondary users (SUs) sharing their detection results. However, a large number of cooperative SUs may induce great sensing delay, which degrades the performance of secondary transmissions. In this paper, we jointly consider cooperative sensing and cognitive transmission in cognitive radio networks, aiming to achieve efficient secondary access with low sensing overhead under both the sensing time and reporting power limitations, where primary users are guaranteed to be sufficiently protected. We first propose an adaptive sensing scheme to lower the detection time while not degrading the detection probability. Then, based on the proposed adaptive sensing scheme, an efficient cognitive transmission protocol is well designed, which improves the throughput of secondary transmissions while ensuring the QoS of primary transmissions. We analyze the performance for the proposed secondary access framework in terms of misdetection probability, average detection time and normalized secondary throughput, respectively, and derive their closed-form expressions over Rayleigh fading channels with considering the reporting errors accordingly. We also study the problems of optimizing the number of cooperative SUs to minimize the misdetection probability and average detection time, and maximize the normalized secondary throughput for proposed framework. Simulation results reveal that the proposed framework outperforms the traditional case significantly.

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Relay selection in underlay cognitive networks with fixed transmission power nodes

Hussain

Abdallah

Alouini

et al. 2013

Trans. Emerging Tel. Tech.

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Underlay cognitive networks operate simultaneously with primary networks satisfying stringent interference constraints, which reduces their transmission power and coverage area. To reach remote destinations, secondary sources use relaying techniques. Selecting the best relay among the available ones is a well known technique. Recently, selective cooperation is investigated in cognitive networks where the secondary nodes can adapt their transmission power to always satisfy the interference threshold. In this paper, we investigate a situation where the secondary nodes have a fixed transmission power and may violate the interference threshold. We present two relay selection schemes; the first one excludes the relays not satisfying the interference constraint and then picks up a relay from the remaining ones that can provide the maximum signal‐to‐noise ratio (SNR). The other scheme uses a quotient of the relay link SNR and the interference from the relay to the primary user and optimizes it to maximise the relay link SNR. We derive closed form expressions for outage probability, bit error rate, channel capacity and diversity of the system for both schemes by using tight approximations. We also study mutual effects of interference. Simulation results confirm the analytical results and reveal that the relay selection is feasible at low SNRs. Copyright © 2013 John Wiley & Sons, Ltd.

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Cognitive Transmissions with Multiple Relays in Cognitive Radio Networks

Cited by 117 publications

References 23 publications

A Cooperative Sensing Based Cognitive Relay Transmission Scheme Without a Dedicated Sensing Relay Channel in Cognitive Radio Networks

A Cooperative Sensing Based Cognitive Relay Transmission Scheme Without a Dedicated Sensing Relay Channel in Cognitive Radio Networks

Efficient secondary access with intelligent spectrum sensing in cognitive radio networks

Relay selection in underlay cognitive networks with fixed transmission power nodes

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