GA based dynamic spectrum allocation in UHF-ISM band of 902–928MHz with RADAR as primary user for cognitive radio
25 Jul 2013-pp 182-188
TL;DR: A novel integrated approach to Cognitive Radio environment with Radar signals of type linear frequency modulation (LFM) as Primary User (PU) as primary user integrated with Multi-Objective Genetic Algorithm (MOGA) for dynamic spectrum allocation is suggested.
Abstract: A novel integrated approach to Cognitive Radio environment with Radar signals of type linear frequency modulation (LFM) as Primary User (PU) is suggested in this paper. The approach consists of spectrum sensing of Radar signals through Wigner-Hough transformation process integrated with the learning and adaptation using Multi-Objective Genetic Algorithm (MOGA) for dynamic spectrum allocation. The objective of minimizing the interference in the presence of radar signal and maximizing the spectral efficiency when radar signal is not detected are considered. In addition, the objective of minimizing the power consumption is also considered. The functionality of the process considers the operation of NI-USRP ® device as SU and radar as PU over ISM-UHF band of 902-928MHz for attaining the fitness's of the SU parameters as desired. For validation, existing method for co-existence of SU with radar is compared for data-rate with the proposed method.
Citations
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15 Dec 2016
TL;DR: This paper investigates existing spectrum sharing methods facilitating coexistence of various RF systems, and studies more general coexistence scenarios and methods such as coexist of communication systems with similar priorities, utilizing similar or different protocols or standards.
Abstract: Due to the explosive growth of wireless devices and wireless traffic, the spectrum scarcity problem is becoming more urgent in numerous Radio Frequency (RF) systems. At the same time, many studies have shown that spectrum resources allocated to various existing RF systems are largely underutilized. As a potential solution to this spectrum scarcity problem, spectrum sharing among multiple, potentially dissimilar RF systems has been proposed. However, such spectrum sharing solutions are challenging to develop due to the lack of efficient coordination schemes and potentially different PHY/MAC properties. In this paper, we investigate existing spectrum sharing methods facilitating coexistence of various RF systems. The cognitive radio technique, which has been the subject of various surveys, constitutes a subset of our wider scope. We study more general coexistence scenarios and methods such as coexistence of communication systems with similar priorities, utilizing similar or different protocols or standards, as well as the coexistence of communication and non-communication systems using the same spectral resources. Finally, we explore open research issues on the spectrum sharing methods as well as potential approaches to resolving these issues.
46 citations
01 Jan 2012
TL;DR: In this article, the authors consider the best linear predictor (BLP) of functional autoregressive processes built with orthogonal projection on linearly closed subspaces and show almost sure convergence and exponential bounds for the predictors.
Abstract: We consider the Best Linear Predictor (BLP) of Functional Autoregressive Processes built with orthogonal projection on linearly closed subspaces introduced by R. Fortet (1995). This approach directly focuses on the prediction of this class of processes and we show almost sure convergence and exponential bounds for the predictors BLP. Then we improve the existing results in the literature. We give the almost sure convergence of the predictors BLP for C[0;1]-valued autoregressive process when it ruled by a bounded linear operator. Our conditions essentially carry on the decay rate of the eigenvalues of the covariance operator of the process. We illustrate the finite sample performance of the BLP predictors by a simulation study and through real examples from climatology and consumption of electrical energy. We compare with others prediction methods existing in the literature and enlighten on the link between the convergence rates of BLP predictors and the presence of the first eigenvalues of the covariance operator.
30 citations
TL;DR: This article will present the importance of multi-objective optimization (MOO) in cognitive radio networks (CRNs) and discuss about the fundamental differences in single objective optimization (SOO) and MOO techniques, in order to solve MOO problems associated with CRNs.
17 citations
Dissertation•
01 Jan 2018
TL;DR: Findings indicated that currently implemented coexistence solutions are not sufficient and that there is a need for cross-industry collaboration to reach an efficient and effective spectrum sharing method between military radars and radio access networks.
Abstract: Demand for radio frequencies is high due to increasing capacity need for the emerging
radio access network, 5G. Hence, the radio spectrum is expected to be more
crowded than it is today with users of different radio services. Military radars and
radio access networks are two different services that potentially face coexistence.
However, interference can occur between users, which undermines the performance
of military radars and thereby also national security, which military radar providers,
e.g. Saab group, need to address. Hence, the purpose is to investigate how Saab
Group can adapt its resources and capabilities effectively, considering a new emerging
coexistence environment due to radio spectrum scarcity driven by 5G capacity
demand.
The research methodology was split in three main parts. Firstly, a documentary
research was performed to investigate the current coexistence situation and feasible
methods for coexistence. The second method consisted of a delphi study that involved
14 experts from five different stakeholder categories and aimed at predicting
the trend of the coexistence environment between military radars and radio access
networks. The third method was to conduct expert interviews with Saab employees
to investigate what internal technologies that existed within Saab and assess their
coexistence potential with radio access networks.
Findings indicated that currently implemented coexistence solutions are not sufficient
and that there is a need for cross-industry collaboration to reach an efficient
and effective spectrum sharing method between military radars and radio access
networks. The four most feasible coexistence methods were: 1) location-based; 2)
resource allocation; 3) cognitive radars; and 4) interference cancellation. At Saab,
five internal technologies were found to have potential to contribute to coexistence
between military radars and radio access networks.
There are three main resources that Saab can pursue to effectively adapt to the
coexistence trends between military radars and radio access networks: 1) competitive
technologies for the 4 most feasible coexistence methods; 2) close collaborations
with providers of radio access networks to develop common solutions; and 3) extensive
insight and involvement in national and international policy development for
radio spectrum allocation.
5 citations
Cites background from "GA based dynamic spectrum allocatio..."
...The applied objective for cognitive radio is to minimize mutual interference between radar systems and radio access networks while also allowing both services to coexist [85]....
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References
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TL;DR: An overview and tutorial is presented describing genetic algorithms (GA) developed specifically for problems with multiple objectives that differ primarily from traditional GA by using specialized fitness functions and introducing methods to promote solution diversity.
2,943 citations
TL;DR: The overall method is shown to be asymptotically efficient and offers a good rejection capability of the cross terms and a closed form expression is found for the signal-to-noise ratio and the parameter estimation accuracy.
Abstract: The aim of the paper is the performance evaluation of a method for the analysis of mono- or multicomponent linear-frequency modulation (LFM) signals, based on the Hough transform of the Wigner-Ville distribution of the signals. A closed form expression is found for the signal-to-noise ratio and the parameter estimation accuracy. The overall method, as any nonlinear method, exhibits a threshold effect. Nevertheless, it is shown to be asymptotically efficient and offers a good rejection capability of the cross terms. >
409 citations
TL;DR: Spectrum shared with radar could be used efficiently for applications such as non-interactive video on demand, peer-to-peer file sharing, file transfers, automatic meter reading, and web browsing, but not for applicationssuch as real-time transfers of small files and VoIP.
Abstract: This paper considers opportunistic primary-secondary spectrum sharing when the primary is a rotating radar. A secondary device is allowed to transmit when its resulting interference will not exceed the radar's tolerable level, in contrast to current approaches that prohibit secondary transmissions if radar signals are detected at any time. We consider the case where an OFDMA based secondary system operates in non-contiguous cells, as might occur with a broadband hotspot service, or a cellular system that uses spectrum shared with radar to supplement its dedicated spectrum. It is shown that even fairly close to a radar, extensive secondary transmissions are possible, although with some interruptions and fluctuations as the radar rotates. For example, at 27% of the distance at which secondary transmissions will not affect the radar, on average, the achievable secondary data rates in down- and upstreams are around 100% and 63% of the one that will be achieved in dedicated spectrum, respectively. Moreover, extensive secondary transmissions are still possible even at different values of key system parameters, including cell radius, transmit power, tolerable interference level, and radar rotating period. By evaluating quality of service, it is found that spectrum shared with radar could be used efficiently for applications such as non-interactive video on demand, peer-to-peer file sharing, file transfers, automatic meter reading, and web browsing, but not for applications such as real-time transfers of small files and VoIP.
144 citations
"GA based dynamic spectrum allocatio..." refers background or methods in this paper
...In [8], the OFDMA SU is allowed to transmit close to the rotating Radar when its interference limit is lower than a predefined threshold, namely a co-existence scenario....
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...187 In [8] the SU are operated in a manner providing low interference to the Radar i....
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...Thereby, to validate the proposed method, the data-rate attained with method in [8] and the paper is compared....
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12 Apr 2010
TL;DR: Several approaches designed to enhance the convergence time and/or improve the performance results of genetic algorithm-based search engine for cognitive radio networks are presented, including techniques such as population adaptation, variable quantization, variable adaptation, and multi-objective genetic algorithms (MOGA).
Abstract: Genetic algorithms are well suited for optimization problems involving large search spaces. In this paper, we present several approaches designed to enhance the convergence time and/or improve the performance results of genetic algorithm-based search engine for cognitive radio networks, including techniques such as population adaptation, variable quantization, variable adaptation, and multi-objective genetic algorithms (MOGA). Note that the time required for a genetic algorithm to reach a decent solution substantially increases with system complexity, and thus techniques are needed that will help facilitate achieving adequate results over a short period of time.
46 citations
"GA based dynamic spectrum allocatio..." refers methods in this paper
...183 ective methods in o multi-objective ominated Sorting proach method of ime in [13] and ided faster results eports MOGA for and learning with on learning with y user with two...
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Dissertation•
30 Apr 2008
TL;DR: This thesis explores genetic algorithm and rule-based optimization techniques used by cognitive radios to make operating parameter decisions and proposes and compares two control methods.
Abstract: This thesis explores genetic algorithm and rule-based optimization techniques used by cognitive radios to make operating parameter decisions. Cognitive radios take advantage of intelligent control methods by using sensed information to determine the optimal set of transmission parameters for a given situation. We have chosen to explore and compare two control methods. A biologically-inspired genetic algorithm (GA) and a rule-based expert system are proposed, analyzed and tested using simulations. We define a common set of eight transmission parameters and six environment parameters used by cognitive radios, and develop a set of preliminary fitness functions that encompass the relationships between a small set of these input and output parameters. Five primary communication objectives are also defined and used in conjunction with the fitness functions to direct the cognitive radio to a solution. These fitness functions are used to implement the two cognitive control methods selected. The hardware resources needed to practically implement each technique are studied. It is observed, through simulations, that several trade offs exist between both the accuracy and speed of the final decision and the size of the parameter sets used to determine the decision. Sensitivity analysis is done on each parameter in order to determine the impact on the decision making process each parameter has on the cognitive engine. This analysis quantifies the usefulness of each parameter.
45 citations