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Cognitive network

About: Cognitive network is a research topic. Over the lifetime, 4213 publications have been published within this topic receiving 107093 citations.


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01 Aug 2011
TL;DR: This collective work provides engineers, researchers and radio designers with the necessary information from mathematical analysis and hardware architectures to design methodology and tools, running platforms and standardization in order to understand this new cognitive radio domain.
Abstract: Software radio ideally provides the opportunity to communicate with any radio communication standard by modifying only the software, without any modification to hardware components. However, taking into account the static behavior of current communications protocols, the spectrum efficiency optimization, and flexibility, the radio domain has become an important factor. From this thinking appeared the cognitive radio paradigm. This evolution is today inescapable in the modern radio communication world. It provides an autonomous behavior to the equipment and therefore the adaptation of communication parameters to better match their needs. This collective work provides engineers, researchers and radio designers with the necessary information from mathematical analysis and hardware architectures to design methodology and tools, running platforms and standardization in order to understand this new cognitive radio domain.

34 citations

Journal ArticleDOI
TL;DR: This paper specifies the case with a single SU and multiple PUs, where both the SU and the PUs are orthogonal frequency-division multiplexing (OFDM) modulated, and proposes a novel iterative power-loading algorithm with low computational complexity to realize the power loading.
Abstract: Conflict-free power allocation for secondary users (SUs) in cognitive networks is a challenging problem because the accessible spectrum of the SUs is shared with the primary users (PUs). The problem becomes particularly difficult when the objective is to achieve maximum network capacity considering the mutual interference between the PUs and the SUs. In this paper, we specify the case with a single SU and multiple PUs, where both the SU and the PUs are orthogonal frequency-division multiplexing (OFDM) modulated. The power allocation for the subcarriers of the SU is modeled into a constrained optimization problem, where the mutual interference between the SU and the PUs is comprehensively formulated as restrictions on the SU's transmission power. As a result, the proposed modeling scheme restrains the interference to the PUs, as well as maximizing the capacity of the SU. A novel iterative power-loading algorithm with low computational complexity is proposed to realize the power loading. On this basis, a suboptimal integral-bit-loading algorithm is further presented. In a simplified scenario, simulation results are exhibited to confirm the efficiency of the proposed power and bit-loading algorithms. Finally, the influence of the mutual interference on the SU's power/bit loading and the system capacity is illustrated.

34 citations

Journal ArticleDOI
TL;DR: An impressive design of a low complexity and high efficiency dynamic spectrum access technique for cognitive radio networks that does not require central controllers nor the pre-establishment and maintenance of common control channels, yet can provide throughput and fairness levels that approach the performance of centralized systems.
Abstract: Cognitive radio is an emerging wireless technology that is envisaged as a solution to the spectrum scarcity issue. To improve spectrum utilization, cognitive (unlicensed) wireless users are assigned an opportunistic access to vacant channels on the condition they avoid interference with primary (licensed) users. In this paper we present an impressive design of a low complexity and high efficiency dynamic spectrum access technique for cognitive radio networks. This spectrum assignment algorithm does not require central controllers nor the pre-establishment and maintenance of common control channels. Yet, it can provide throughput and fairness levels that approach the performance of centralized systems. In addition, the proposed technique reacts extremely well to disturbances in the cognitive radio network configuration, including when primary users are activated, or when newcomer cognitive users join the network. Furthermore, we present in this work an analytical model that can be used to provide quick predictions of the performance of our proposed algorithm.

34 citations

Journal ArticleDOI
TL;DR: This work considers a multi-channel multi-user cognitive radio MIMO network in which each node controls its antenna radiation directions and allocates power for each data stream by adjusting its precoding matrices, and introduces pricing policies that employ a novel network interference function.
Abstract: We consider a multi-channel multi-user cognitive radio MIMO network in which each node controls its antenna radiation directions and allocates power for each data stream by adjusting its precoding matrices. Under a noncooperative game, we optimize the set of precoding matrices (one per channel) at each node so as to minimize the total transmit power in the network. Using recession analysis and the theory of variational inequalities, we obtain sufficient conditions that guarantee the existence and uniqueness of the game's Nash Equilibrium (NE). Low-complexity distributed algorithms are also developed by exploiting the strong duality of the convex per-user optimization problem. To improve the efficiency of the NE, we introduce pricing policies that employ a novel network interference function. Existence and uniqueness of the new NE under pricing are studied. Simulations confirm the effectiveness of our joint optimization approach.

34 citations

Proceedings ArticleDOI
12 Apr 2010
TL;DR: The solution features a spectrum-aware neighbor discovery and clustering scheme that works in conjunction with a network coded cognitive control channel in order to allow Cognitive Radio devices to opportunistically access the unused spectrum.
Abstract: In this paper we present a solution for the realization of large Cognitive Radio Networks. The solution features a spectrum-aware neighbor discovery and clustering scheme that works in conjunction with a network coded cognitive control channel in order to allow Cognitive Radio devices to opportunistically access the unused spectrum. We evaluate the performance of the proposed solution with respect to the characteristics of the formed clusters as well as the reliability of the dissemination of the control information within the cluster.

34 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202317
202234
202175
2020104
2019121
2018134