Comparison of spectrum occupancy measurements using software defined radio RTL-SDR with a conventional spectrum analyzer approach

In the present day Cognitive Radio has become a realistic option for solution of the spectrum scarcity problem in wireless communication. Recently, the TV band has attracted attention due to the considerable potential for exploitation of available TV white space which is not utilized based on time and location. In this paper, we investigate spectrum occupancy of the UHF TV band in the frequency range from 470 to 862MHz by using two different devices, the low cost device RTL-SDR and high cost spectrum analyzer. The spectrum occupancy measurements provide evidence of the utility of using the inexpensive RTL SDR and illustrate its effectiveness for detection of the percentage of spectrum utilization compared with results from the conventional high cost Agilent spectrum analyzer, both systems employing various antennas

Cooperative wideband spectrum sensing with multi-bit hard decision in cognitive radio

Cognitive radio offers an increasingly attractive solution to overcome the underutilization problem. A sensor network based cooperative wideband spectrum sensing is proposed in this paper. The purpose of the sensor network is to determine the frequencies of the sources and reduced the total sensing time using a multi-resolution sensing technique. The final result is computed by data fusion of multi-bit decisions made by each cooperating secondary user. Simulation results show improved performance in energy efficiency

Spectrum occupancy measurements and lessons learned in the context of cognitive radio

Various measurement campaigns have shown that numerous spectrum bands are vacant even though licenses have been issued by the regulatory agencies. Dynamic spectrum access (DSA) based on Cognitive Radio (CR) has been regarded as a prospective solution to improve spectrum utilization for wireless communications. Empirical measurement of the radio environment to promote understanding of the current spectrum usage of the different wireless services is the first step towards deployment of future CR networks. In this paper we present our spectrum measurement setup and discuss lessons learned during our measurement activities. The main contribution of the paper is to introduce global spectrum occupancy measurements and address the major drawbacks of previous spectrum occupancy studies by providing a unifying methodological framework for future spectrum measurement campaigns

Experimental detection using cyclostationary feature detectors for cognitive radios

© 2014 IEEE. Signal detection is widely used in many applications. Some examples include Cognitive Radio (CR) and military intelligence. Without guaranteed signal detection, a CR cannot reliably perform its role. Spectrum sensing is currently one of the most challenging problems in cognitive radio design because of various factors such as multi-path fading and signal to noise ratio (SNR). In this paper, we particularly focus on the detection method based on cyclostationary feature detectors (CFD) estimation. The advantage of CFD is its relative robustness against noise uncertainty compared with energy detection methods. The experimental result present in this paper show that the cyclostationary feature-based detection can be robust compared to energy-based technique for low SNR levels

Quality measurements of an UWB reduced-size CPW-fed aperture antenna

The paper presents a characterization of a compact co-planar waveguide (CPW)-fed slot loaded low return loss planar printed antenna designed for wireless communication and ultra-wideband (UWB) applications. Following a review of the antenna design, which was implemented and simulated using Agilent's Advanced Design System (ADS), the paper presents laboratory measurements of relative gain and impulse response transformed from the frequency domain. An antenna quality metric based on time-domain S21 is discussed and related to antenna quality metrics such as the System Fidelity Factor (SFF)

Availability and utilizationof instructional technologies in supervision in public secondary schools during coivid-19 era in cross river state, nigeria

This study investigated the availability and utilization of instructional technologies in supervision in public secondary schools in Cross River State, Nigeria. To achieve the purpose of this study, descriptive survey research design was adopted; a research question was raised and two hypotheses were formulated to guide the study. The population of this study comprised the entire 279 respondents drawn through census approach from all the public secondary schools in Cross River State.Data collection was carried out with the use of researchers’ constructed instrument titled: Availability and Utilization of Instructional Technologies in School Supervision during COVID-19Pandemic Survey (AUITSSCOVID-19PS). The instrument was validated and reliability was established through Cronbach Alpha analysis which yielded .90 hence indicating high internal consistency in achieving the purpose of this study. In order to answer the research question, data collected were analyzed using mean and standard deviation while the hypotheses were tested with independent t-test statistical techniques. The results showed that the availability of instructional technologies used in school supervision is very low. It was also found that the extent of utilization of instructional technologies in school supervision is very low. Based on the findings and discussion, conclusions were made. It was therefore recommended among others that the government should ensure that adequate instructional technologies are provided and utilized in supervising secondary schools especially during this period of global COVID-19 pandemic

Mengembangkan moderasi beragama mahasantri melalui ta’lim ma’hadi di pesantren mahasiswa

Abstract: The aims of this research is to discribe and a analyze of ta’lim ma’hadi in al-Hikam Malang Student Islamic Boarding School Malang, and also the values that are implemented to develop the moderate character of the mahasantri religion. This study used a qualitative approach with a case study design. The data in this study were taken through interviews, observation, and document techniques. The results of this study indicate that the al-Hikam Malang student boarding school uses three strategies in religious moderation, namely, nurturing patterns, teaching patterns, and religious patterns. The three strategies are integral in the curriculum that is implemented there. Through the applied curriculum, kyai and asatidz as qudwah hasanah internalize the values of justice, balance, harmony, moderation. As well as being a moderate Muslim, the mahasantri al-Hikam graduate is expected to become a successful entrepreneur. Abstrak: Tujuan penelitian ini adalah untuk mendeskripsikan dan menganalisis tentang sistem ta’lim ma’hadi di Pesantren Mahasiswa Al-Hikam Malang serta nilai-nilai yang diimplementasikan guna mengembangkan karakter moderasi beragama mahasantri. Penelitian ini menggunakan pendekatan kualitatif dengan rancangan studi kasus. Data dalam penelitian ini diambil melalui wawancara, observasi dan teknik dokumen. Hasil dari penelitian ini menunjukkan bahwa pesantren mahasiswa al-Hikam Malang menggunakan tiga strategi dalam moderasi agama yaitu, pola kepengasuhan, pola pengajaran dan pola kesantrian. Ketiga strategi tersebut integral dalam kurikulum yang diimplementasikan disana. Melalui kurikulum yang diterapkan, seorang kyai dan asatidz sebagai qudwah hasanah yang menginternalisasikan nilai keadilan, keseimbangan, kerukunan, moderat. Lulusan mahasantri al-Hikam disamping menjadi muslim yang moderat, ia diharapkan menjadi entrepreneur yang sukses

Áreas de produção de algodão em Mato Grosso: nematoides, murcha de fusarium, sistemas de cultivo, fertilidade e física de solo.

A produção de algodão no estado de Mato Grosso é comprovadamente eficiente e rentável. A cada safra aumentam a tecnificação da cultura e o conhecimento acumulado. Reflexo disso é o crescimento da área ocupada por essa cultura em Mato Grosso, que representa mais de 50% do algodão plantado no país. No entanto, problemas relacionados à ocorrência de nematoides e doenças a eles associadas vêm crescendo e preocupando os produtores. Existem vários exemplos de inviabilidade de áreas em função desses parasitas, principalmente em locais que foram tradicionais no cultivo do algodoeiro. Práticas de manejo deverão ser incentivadas para reduzir ou pelo menos manter estável o problema. Para que a melhor estratégia possa ser utilizada, além de quantificar quais são as espécies presentes, é fundamental conhecer o sistema de produção no qual atua o produtor, o histórico da área, bem como as condições físicas e químicas do solo. O trabalho aqui relatado enfoca um esforço nesta direção, realizado em parceria entre o Instituto Mato-grossense do Algodão (IMAmt), a Associação Mato-grossense dos Produtores de Algodão (AMPA), o Instituto Brasileiro do Algodão (IBA), a Associação dos Produtores de Sementes de Mato Grosso (Aprosmat) e quatro unidades da Empresa Brasileira de Pesquisa Agropecuária (Embrapa): a Embrapa Agrossilvipastoril, Embrapa Algodão, Embrapa Instrumentação e Embrapa Agropecuária Oeste.bitstream/item/115841/1/cpamt-2014-matos-producao-algodao-mt.pd