scholarly journals Komunikasi Suara Sinyal Digital Dengan Transmisi Frekuensi 2,4 Ghz

2019 ◽  
Vol 6 (2) ◽  
pp. 93-102
Author(s):  
Ahmad Wahyu Purwandi ◽  
Abdul Rasyid ◽  
Guntur Wahyu Sejati
Keyword(s):  
Radio Frequency ◽  
Frequency Spectrum ◽  
Communication Technology ◽  
Digital Technology ◽  
Communication Systems ◽  
Radio Station ◽  
Spectrum Efficiency ◽  
Digital Data ◽  
High Tech ◽  
Radio Communication

The limitations of developing high-tech communication systems cause the area of people who can use this service to be uneven. One technology that can be used for areas not yet reached by this high-tech communication service is to use radio communication technology. Today radio communication technology continues to develop and produce an increasingly limited frequency spectrum. One way to improve the efficient use of available frequency spectrums is the transition from analog technology to digital technology. A very significant benefit in the use of digital technology is to save the use of radio frequency spectrum bandwidth with signal compression techniques. One device that still uses analog technology is a handy talky (HT). In addition to the lack of frequency spectrum efficiency, HT technology still requires a radio station license (ISR) for its use. This experiment designed a two-way digital audio communication system that was transmitted using the NRF24L01 radio frequency transceiver module on the 2.4Ghz frequency. Analog input data from the microphone will be converted into digital data through the ADC (Analog to Digital Converter) process using a microcontroller and the digital data that will be sent is first digitally modulated using GFSK modulation then transmitted digitally. On the other hand data that already contains voice information received again by another NRF24L01 transceiver is received by the Arduino microcontroller and then formed into a PWM signal (pulse width modulation) and then released to the speaker. So the method of using digital transmission can produce efficiencies in the frequency spectrum.  

Radio Frequency Support for Space Systems Based on Multi-Satellite Constellations Taking into Account the ITU-R Requirements and the WRC-19 Results

2021 ◽  
Vol 8 (4) ◽  
pp. 72-76
Author(s):  
А. А. Talanov ◽  
◽  
S. А. Fedotov ◽  
А. М. Stepanov ◽  
◽  
...  
Keyword(s):  
Radio Frequency ◽  
Frequency Spectrum ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Satellite Communication ◽  
Space Systems ◽  
Satellite Constellations ◽  
Broadband Internet ◽  
State Commission ◽  
Radio Frequency Spectrum

Deployment of space systems based on multi-satellite constellations to provide broadband Internet access and communication services acutely raises the question of their radio frequency support including issues of electromagnetic compatibility (EMC) between competing space systems using multi-satellite constellations (StarLink, OneWeb, Kuiper, etc.), their EMC with traditional space systems (satellite communication systems that employ spacecraft in geostationary and non-geostationary orbits, space systems of other services), as well as regulatory issues of entering into service and staged deployment of space systems. The article formulates the problematic issues of radio frequency support of modern space systems taking into account the trends of satellite constellations deployment and proposes the solutions with consideration to international and national requirements in the regulation of radio frequency spectrum including the ITU requirements and the requirements of Russian State Commission for Radio Frequencies. The paper shows the ways to share the radio frequency spectrum to meet new requirements of the World Radiocommunication Conference 2019 (WRC-19).

DETERMINATION OF THE NORMS OF FREQUENCY-TERRITORIAL DIVERSION DURING THE DEVELOPMENT OF 5G TECHNOLOGY IN 3,4–4,2, 4,4–5, 14,5–15,35 GHZ FREQUENCY RANGES

2021 ◽  
pp. 24-36
Author(s):  
V. S. Lazorenko ◽  
О. V. Plygunov
Keyword(s):  
Radio Frequency ◽  
Frequency Spectrum ◽  
Electromagnetic Compatibility ◽  
Radio Communication ◽  
Fifth Generation ◽  
Radio Frequency Spectrum ◽  
Load Analysis ◽  
Technical And Organizational Measures ◽  
Theoretical Assessment

The article presents scientific and technical proposals on the possibility of joint use of radio frequency spectrum of the fifth-generation mobile radio communication means and existing departmental radio-electronic facilities. On the basis of the load analysis, using the method of theoretical assessment of electromagnetic compatibility, the norms of territorial diversion between radio means are obtained. On the basis of the results of the calculations, it is possible to determine the subbands in which the joint use of radio means is possible, subject to optimization of the frequency-territorial plan and implementation of technical and organizational measures to ensure electromagnetic compatibility.

scholarly journals 25 years of the TETRA standard and technology for contemporary digital trunking systems of professional mobile radio communications

2021 ◽  
Vol 69 (2) ◽  
pp. 426-460
Author(s):  
Slađan Svrzić
Keyword(s):  
Frequency Spectrum ◽  
Historical Development ◽  
Communication Systems ◽  
Data Transfer ◽  
Armed Forces ◽  
Mobile Radio ◽  
Radio Communication ◽  
Radio Communications ◽  
The World ◽  
Mobile Radio Communications

Introduction/purpose: For the construction of functional mobile radio communication systems today, the trunking systems of digital mobile radio communications are almost exclusively used, the main representative of which is the system with the application of TETRA standards. This article describes the beginnings and historical development of this standard, with the activities of ETSI and TETRA MoU in the fight for the availability and harmonization of the frequency spectrum. Methods: A description of relevant issues of the origin and development of the TETRA 1 standard is given as well as the analysis of the characteristic moments of the innovated TETRA 2 standard. Results: This article describes the beginnings and historical development of this standard, with the activities of ETSI and TETRA MoU in the fight for the availability and harmonization of the frequency spectrum. It also systematize the use of the key TETRA systems in the world and shows its share in the world market by sectors, emphasizing the dilemma of its further development at the crossroads after 25 years of existence. Also, a basic overview of the TETRA 1 standard is given while the basic elements and the principle of its application are described. The innovated TETRA 2 standard and the improvements achieved in the way of data transmission are described in more detail; the process of interoperability certification and, in connection with that, the entry of TETRA into the North American market is emphasized. The parameters selected for advanced data transfer according to the TETRA 2-TEDS standard are presented and analyzed, together with an overview of some limitations during practical application. Conclusion: In the conclusion, the current moment of TETRA is analyzed with a focus on its future after 25 years of development, emohasizing a possibility of modernizing and improving the TETRA network of the Ministry of the Interior of Serbia for the needs of the MoD and the Serbian Armed Forces.

scholarly journals Method and algorithm for the insertion of new transmitter into existing frequency plans for radio communication services

2006 ◽  
Vol 19 (1) ◽  
pp. 13-26
Author(s):  
Slavenko Rasajski
Keyword(s):  
Radio Frequency ◽  
Frequency Spectrum ◽  
Radio Communication ◽  
Communication Services ◽  
Software Support ◽  
Technical Requirements ◽  
Radio Frequency Spectrum ◽  
Protection Ratio

This paper deals with the procedure of new transmitter insertion into the existing Plan, including results of transmitter insertion simulation with software support developed for the proposed algorithm. The same procedure can also be applied for other radio communication services using the corresponding plans and technical requirements databases (minimum field protection ratio, etc). The proposed algorithm ensures an efficient and economical use of radio frequency spectrum.

scholarly journals Radio Contact Establishment Out of Iraqi Boarder using Nicosia Ionosonde Real data

2018 ◽  
Vol 14 (2) ◽  
pp. 103-107
Author(s):  
Ahmed Hassan
Keyword(s):  
Communication Systems ◽  
Real Data ◽  
Optical Fiber Communication ◽  
Experimental Results ◽  
Radio Station ◽  
Advanced Technology ◽  
Radio Communication ◽  
Fiber Communication ◽  
Radio Contact ◽  
Communication Path

Although the advanced technology in satellites and optical fiber communication systems exists now a day, but the researches in HF sky wave propagation for Mesopotamia (Iraq) area is suffered from shortage. In this paper, the novelty is that the communication path from Baghdad to any distance out of Iraqi border had been predicted, calculated and measured experimentally by using real data (Ionogram) supplemented by Nicosia Ionosound station 1000Km from Baghdad and a radio station model TS-130SE as a transmitter. The Predicted results generated by using MATLAB and NTIA/ITS software package like VOACAP. Radio communication using TS-130SE with 36 countries had been done experimentally. A comparison between the theoretical and experimental results was done. The experimental results were in the range of the predicated results which emphasis proposed method Presented in this paper.

scholarly journals Determination of Effective Mode Selection for Ensuring Spectrum Efficiency with Massive MIMO in IoT Systems

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 706
Author(s):  
Osman Dikmen ◽  
Selman Kulaç
Keyword(s):  
Frequency Spectrum ◽  
Communication Systems ◽  
Mode Selection ◽  
Spectrum Efficiency ◽  
Wireless Communication Systems ◽  
Infrastructure Monitoring ◽  
Smart Cars ◽  
Time Division ◽  
Day By Day

Wireless Sensor Networks (WSNs) based on Internet of Things (IoT) applications are increasing day by day. These applications include healthcare, infrastructure monitoring, smart homes, wearable devices and smart cars. However, considering the fact that many different application areas will emerge in next generation wireless communication systems, efficient use of frequency spectrum is important. Because the whole frequency spectrum is now very crowded, it is important to ensure maximum spectrum efficiency for effective WSNs based on IoT. This study sought to determine which mode more effectively achieves spectrum efficiency for the performance of effective IoT systems under given conditions with respect to the length of the pilot sequence, Time Division Duplexing (TDD) or Frequency Division Duplexing (FDD). The results were obtained by Monte Carlo simulations. To the best of our knowledge, a study of effective mode selection analysis for spectrum efficiency in IoT based systems has not been available in the literature yet. The results of this study are useful for determining the appropriate design conditions for WSNs based on IoT.

scholarly journals Relay Positions Considering Interference from Other Sub-Channels in OFDMA-Based D2D Group-Casting Systems

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1374 ◽  
Author(s):  
Minjoong Rim ◽  
Eulhyeon Go
Keyword(s):  
Communication Technology ◽  
Communication Systems ◽  
Multiple Access ◽  
Base Station ◽  
Spectrum Efficiency ◽  
D2d Communication ◽  
D2d Communications ◽  
Ofdma System ◽  
Transmission Distance ◽  
Secure Transmission

Device-to-device (D2D) communication is a technique for direct communication between devices without going through a base station or other infrastructure. D2D communication technology has the advantages of improving spectrum efficiency and reducing transmission delay and transmission power. In D2D communication systems, orthogonal frequency-division multiple access (OFDMA) is widely used to maintain similarities with cellular communication systems and to secure transmission distance. OFDMA allows flexible and efficient use of frequency resources by allocating sub-channels independent to each user. In this paper, we consider a D2D overlay system that uses different sub-channels for cellular and D2D communications. In theory, the signals on different sub-channels of an OFDMA system are orthogonal and not interfered with each other. However, in a D2D communication system, which operates in a distributed manner, there is non-negligible interference from other sub-channels because of in-band emissions. In this paper, we address the performance degradation resulting from the interference from other sub-channels for OFDMA-based D2D group-casting systems. We consider three different scenarios of D2D relay, and we find the relay position that minimizes the outage probability. The simulation and analytical results show that the optimal location of a relay can be considerably different according to the source location and the target scenario.

scholarly journals REGULATION OF RADIO FREQUENCY SPECTRUM AND ITS IMPLEMENTATION CHALLENGES IN THE PERSPECTIVE OF INTERNATIONAL LAW

2019 ◽  
Vol 4 (1) ◽  
pp. 21
Author(s):  
Jean Claude Geofrey Mahoro ◽  
Agus Pramono
Keyword(s):  
Radio Frequency ◽  
Frequency Spectrum ◽  
Natural Resource ◽  
Radio Communication ◽  
International Telecommunication Union ◽  
Implementation Challenges ◽  
International Telecommunication ◽  
Fair Competition ◽  
Radio Frequency Spectrum ◽  
Telecommunication Operators

The radio frequency spectrum is a limited natural resource, which is very important and strategic in the operation of telecommunications. Considering that it is a limited natural resource, its management is regulated internationally by the International Telecommunication Union (ITU), in which details are set out in the radio regulations (RR) as an integral part of the ITU Convention. The study is based on applicable legal regulations and is supported by literature studies. The results of the study indicate that the regulation of the radio frequency spectrum is based on radio regulations, international agreements within the ITU through the World Radio communication Conference forum. The implications of regulating the use of the radio frequency spectrum always take into account the general public needs for the dynamics of the progress in telecommunications technology, of which implementation of its utilisation rests in the principle of fairness and equity between regions, and efficiency. Therefore, all policies made are directed at creating a market balance, ensuring fair competition between telecommunication operators as a potential to prevent market dominance, as well as protecting consumers.

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