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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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Journal ArticleDOI
TL;DR: It is shown that random clustering causes the system to lose some of the available degrees of freedom, and analytical expression of the outage probability of the system for therandom clustering and the proposed maximum-SNR clustering scheme with antenna selection is provided.
Abstract: We study the performance of a dual-hop cognitive radio network sharing the spectrum of a primary network in an underlay fashion. In particular, the cognitive network consists of a source, a destination, and multiple nodes employed as amplify-and-forward (AF) relays. To improve the spectral efficiency, all relays are allowed to instantaneously transmit to the destination over the same frequency band. We present the optimal power allocation that maximizes the received signal-to-noise ratio (SNR) at the destination while satisfying the interference constrains of the primary network. The optimal power allocation is obtained through an eigensolution of a channel-dependent matrix and is shown to transform the transmission over the nonorthogonal relays into parallel channels. Furthermore, while the secondary destination is equipped with multiple antennas, we propose an antenna selection scheme to select the antenna with the highest SNR. To this end, we propose a clustering scheme to subgroup the available relays and use antenna selection at the receiver to extract the same diversity order. We show that random clustering causes the system to lose some of the available degrees of freedom. We provide analytical expression of the outage probability of the system for the random clustering and the proposed maximum-SNR clustering scheme with antenna selection.

16 citations

Journal ArticleDOI
TL;DR: A two-level authentication scheme for communication in a CRN that relies on public- and symmetric-key cryptography, instead of using a digital signature-based approach, in order to improve network security in terms of resource availability and accessibility.
Abstract: Cognitive radio (CR) has been introduced to accommodate the steady increment in the spectrum demand. Wireless security in CR network (CRN) is a challenging technical area due to the dynamic and unique characteristics of CRNs. As a cognitive node can dynamically join or leave the spectrum, providing secure communication becomes problematic and requires more investigation. Authentication is a primary security property in wireless networks, wherein the identity of a cognitive node is verified before providing access to available resources. In this paper, a two-level authentication scheme for communication in a CRN is proposed. Before joining the network, a CR node is validated by obtaining security credentials from an authorized point. The proposed scheme relies on public- and symmetric-key cryptography, instead of using a digital signature-based approach. It encrypts data between the communicating nodes in order to improve network security in terms of resource availability and accessibility. This mitigates attacks such as reflection attack , denial of service attack , and man-in-the-middle attack . The scheme has been evaluated and verified in terms of security functionality, its correctness, and the performance, which shows less computation and communication requirements.

16 citations

Journal ArticleDOI
TL;DR: The results confirmed that the proposed protocols can outperform the conventional PRS protocols by designing the number of the potential relays appropriately and Monte Carlo simulations are presented to confirm the theoretical‐derivation correction.

16 citations

Journal ArticleDOI
TL;DR: In this paper, the authors provide a survey of the state-of-the-art information theoretic analysis for overlay multi-user (more than two pairs) cognitive networks and report new capacity results.
Abstract: This paper provides a survey of the state-of-the-art information theoretic analysis for overlay multi-user (more than two pairs) cognitive networks and reports new capacity results. In an overlay scenario, cognitive/secondary users share the same frequency band with licensed/primary users to efficiently exploit the spectrum. They do so without degrading the performance of the incumbent users, and may possibly even aid in transmitting their messages as cognitive users are assumed to possess the message(s) of primary user(s) and possibly other cognitive user(s). The survey begins with a short overview of the two-user overlay cognitive interference channel. The evolution from two-user to three-user overlay cognitive interference channels is described next, followed by generalizations to multi-user (arbitrary number of users) cognitive networks. The rest of the paper considers $K$ -user cognitive interference channels with different message knowledge structures at the transmitters. Novel capacity inner and outer bounds are proposed. Channel conditions under which the bounds meet, thus, characterizing the information theoretic capacity of the channel, for both linear deterministic and Gaussian channel models, are derived. The results show that for certain channel conditions distributed cognition, or having a cumulative message knowledge structure at the nodes, may not be worth the overhead as (approximately) the same capacity can be achieved by having only one global cognitive user whose role is to manage all the interference in the network. This paper concludes with future research directions.

16 citations

Proceedings ArticleDOI
01 Nov 2017
TL;DR: A cognitive network method is proposed to optimize V2X communication by combining both WiFi and 920MHz bands to compensate for the short communication distance between communication partners.
Abstract: We developed a system for deterring traffic problems by understanding the road surface condition, collecting information from many vehicles and calling attention at various levels to the driver. We focus on the sharing method of sensor data with road condition using V2X communication. The Wi-Fi communication in the 2.4 GHz band which is the conventional method, has a short communication distance and must understand the communication partner in advance. We use 920 MHz band communication which is long distance communication to compensate for these problems. We propose a cognitive network method to optimize V2X communication by combining both WiFi and 920MHz bands.

16 citations


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