Field Of Satellite Communications Research Articles

Design of millimeter wave broadband polarization reconfigurable horn antenna based on elliptical waveguide polarizer

AbstractA broadband polarized reconfigurable horn antenna for K‐band and Ka‐band is designed using a circular polarizer in the form of an elliptical waveguide and a circular waveguide flange based on a gap structure. The designed noncontact circular waveguide flange with gap structure can switch the antenna excitation signal to different modes of electromagnetic waves by mechanical rotation. When excited by different modes of electromagnetic waves, the designed elliptical waveguide circular polarizer can switch between linear polarization, left‐handed circular polarization, and right‐handed circular polarization. The antenna is analyzed in principle, modeled and simulated, and processed by three‐dimensional printing process. The measured results show that S11 ≤ −15dB, axial ratio ≤ 3 dB, gain ≥14 dBi in 37.8% relative bandwidth range (22.5–33 GHz). The proposed antenna is broadband, multipolar, and reconfigurable, which makes it have broad application prospects in the field of satellite communication and millimeter‐wave communication.

A comparative analysis of convolutional coding and block coding techniques over satellite communication

Reliable data transmission is crucial in the field of satellite communication, and many coding schemes are used to improve this reliability. Two popular coding techniques: convolutional codes and block codes were investigated and compared in this paper. Utilizing a simulated environment, the author investigates the bit error rate (BER) performance of both coding strategies along with a baseline case of no coding. The analysis reveals distinct characteristics and performance attributes of the two coding techniques across a range of signal-to-noise rate (SNR) values. Convolutional codes, with their inherent memory, offer error protection across sequences, while block codes, particularly a Hamming-like 7,3 implementation, provide localized protection for individual blocks. The findings of this study contribute to the understanding of error control strategies in satellite communication, guiding the selection and design of coding methods suitable for various operational scenarios and requirements.

Navigating through Noise Comparative Analysis of Using Convolutional Codes vs. Other Coding Methods in GPS Systems

This research highlights the importance of error-correcting codes in ensuring secure and efficient data transmission over noisy channels. This paper aims to address the issue of limited information regarding the factors that contribute to the effectiveness of the implementation of Convolutional Codes in GPS systems. The research problem revolves around the insufficiency of scholarly sources elucidating the rationale behind the utilization of convolutional codes, specifically in GPS systems, rather than others. Through an in-depth analysis of these factors, this study strives to achieve a comprehensive understanding of the application of Convolutional Codes in GPS. To tackle this research problem, a novel methodology involving comparative analysis is employed. The coding techniques commonly used in satellite communication systems (such as BCH, LDPC, and turbo codes) are carefully examined and compared to the advantages and suitability of Convolutional codes and the Viterbi algorithm for GPS systems. Each coding technique is evaluated based on factors such as error detection and correction capabilities, bandwidth efficiency, computational complexity, and resilience to noise. The key findings of this study shed light on the unique advantages offered by Convolutional codes and the Viterbi algorithm for GPS systems. The analysis reveals that these coding techniques exhibit superior error detection and correction capabilities, efficient bandwidth utilization, and the ability to withstand noise in the GPS communication channel. The results also highlight the computational complexity associated with these techniques, providing valuable insights for the implementation of convolutional codes in GPS systems. Overall, this article contributes to the existing knowledge by providing a comprehensive understanding of the reasons behind the suitability of convolutional codes for GPS systems. The findings of this study serve as a resource for researchers, engineers, and practitioners in the field of satellite communication, aiding in the comprehensive understanding, advancement, and optimization of GPS system designs.

A circularly polarized pyramidal horn antenna based on substrate integrated waveguide

A circularly polarized pyramidal horn antenna based on substrate integrated waveguide (SIW) technology is proposed and developed for Ku-band applications. The proposed horn antenna is excited by the upper and lower SICL differential feed networks placed vertically to each other, so that two orthogonal waveguide modes with the equal amplitude are generated at the horn aperture. A 90° coupling network based on SICL technology is proposed to achieve a 90° phase difference between the two orthogonal waveguide modes, thus realizing the function of left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) of the horn antenna. In addition, in order to make the phase distribution of the horn aperture more uniform, a cross metal strip structure at the horn aperture is proposed, thereby improving the radiation efficiency. The proposed horn antenna is manufactured by using low-cost printed circuit boards (PCBs) process. The measured results show that the proposed circularly polarized pyramidal horn operates at center frequency 12.5 GHz, the measured gain is 8.4 dBi, the relative standing wave and axial ratio (AR) bandwidth are approximately 24% and 5%, respectively. And the radiation aperture efficiency is as high as 78.5%. The developed circularly polarized pyramidal horn antenna can be applied in the field of satellite communications.

Propagation Path and Related Tropospheric, Phenomena on the Satellite-Earth

Attenuation is a major drawback for the field of satellite communication which we can not ignore, but, ofcourse can try to mitigate at an instant. In this project, my focus is on the attenutaion part. I am trying to explain the types of attenuation which is being faced by the signal at tropospheric region. We will see how the signal changes its properties when it passes through tropospheric region. Different type of models is being used by the research scientist for measurement of the attenuation impact over the signal. Many times the models has given the fruitful result but some time they are failed as per different location. I took the Ku-band signal from NSS-6 (geostationary 950E) at an elevation angle of from Kolkata. My result outcome shows that the ITU-R model is the best model out of them and it makes the best predictions for different tropical climates. Based on my experimental result, I am trying to show that the ITU-R model is the best option for our climate. On the other side, I have explained through my project that how much signal depolarized at the different percentage of time at one-minute rain rate distribution.

Low Power, Wide Range Synthesizer for 534 MHz–18.56 GHz Band with FoM of − 192.45 dBc/Hz

A wide range frequency synthesizer is designed with the help of dual voltage tunable Differential Ring Oscillator (DRO). Frequency ranging from 534[Formula: see text]MHz to 18.56[Formula: see text]GHz can be generated using the proposed synthesizer. As proposed circuit utilizes dual voltage tunable DRO, a select input is provided to control the output frequency range. Logic low value (0[Formula: see text]V) of select input generates frequencies from 534[Formula: see text]MHz to 5.08[Formula: see text]GHz whereas logic high value (1.1[Formula: see text]V) of select input enables the frequency generation in the range of 5.08[Formula: see text]GHz to 18.56[Formula: see text]GHz. This work utilizes a single charge pump and single loop filter along with charge pump and bias control circuit. Proposed circuit is designed in GPDK 45-nm CMOS technology with supply voltage of 1.1[Formula: see text]V. Power consumption of the proposed circuits is 2.88[Formula: see text]mW while generating frequency of 7.84[Formula: see text]GHz. Proposed synthesizer demonstrates Figure of Merit (FoM2) of [Formula: see text][Formula: see text]dBc/Hz at this frequency. Because of such a wide spectrum, this synthesizer is well suited in the field of satellite communication, GPS and navigation.

Towards modular and scalable on-board computer architecture

Abstract The demand for satellites and space systems with ever-increasing avionics requirements is constantly growing, whether in the field of satellite communications or earth observation. Traditional architectures for Data Handling Systems (DHS) on satellites are reaching their limits in terms of flexibility, interoperability and reusability, while slowing down the innovation cycle due to costly qualification. With regard to commercial and industrial solutions, it is evident that ‘plug and play’-like systems based on open standards can overcome the above-mentioned disadvantages. For this reason, this paper describes how open standards could affect the architecture of future satellite DHSs. In particular it shows an transition path from the traditional federated architecture to a centralized but modular architecture based on adapted industrial standards.

SatComSim: a Toolkit for Analysis and Optimization of the field of view of Communications Payload in Space-Ground Communication

For high-precision millimeter wave communication tasks, the communication field of view being occluded will seriously affect its communication quality. Accurate analysis of the field of view of the communications payload in space-ground communication, which is occluded by the solar panels and other payloads outside the satellite capsule, is the basis for optimizing the communications payload layout. In order to effectively analyze the occlusion of the communication field of view, this paper proposes a satellite communication field of view calculation simulator - SatComSim, which is based on Pro/E and STK software to obtain the basic data and calculate the occluded communication field of view through collision algorithm to provide important reference analysis results for subsequent research. Finally, we simulate the occlusion of the field of view under different layouts of payloads outside the satellite capsule and field of view ranges based on SatComSim, and optimize the communications payload layout and field of view. The simulation results show the effectiveness of SatComSim in the communications payload field of view analysis, which has an important role in optimizing the communications payload layout and improving the utilization of communication resources.

Satellite ground station site diversity by optimizing SDN-enabled handover

Using Software Defined Network (SDN) in space systems gainsmore focus nowadays. SDN can increase the reliability in satellitecommunication. Many researchers concluded that using SDN in satellitecommunication for both ground segment and space segment, improvespace system reliability. The satellite ground station network has beenalways the backbone of the Space System. From this point of view, thereliability and performance guarantee of this network is mandatory.With the introduction of SDN in the field of satellite communications,greater capabilities have been expected to be achieved, in addition tothe big reduction of operational and capital expenses in deploying andmanagement of satellite ground network equipment. In this paper, theadvantages of using SDN for handover between satellite ground stations(Site Diversity) to ensure higher reliability for the system and to increaseits performance and throughput are discussed. Some scenarios have beenimplemented and shown in this paper to demonstrate the great potentialof using SDN in ground stations handover and to help make decisions incase of link anomalies.

Signal Processing for High-Throughput Satellites: Challenges in New Interference-Limited Scenarios

The field of satellite communications is enjoying a renewed interest in the global telecom market, and very high throughput satellites (V/HTS), with their multiple spot-beams, are key for delivering the future rate demands. In this article, the state-of-the-art and open research challenges of signal processing techniques for V/HTS systems are presented for the first time, with focus on novel approaches for efficient interference mitigation. The main signal processing topics for the ground, satellite, and user segment are addressed. Also, the critical components for the integration of satellite and terrestrial networks are studied, such as cognitive satellite systems and satellite-terrestrial backhaul for caching. All the reviewed techniques are essential in empowering satellite systems to support the increasing demands of the upcoming generation of communication networks.

Traffic Modelling and Simulation of Broadband LEO Satellite Communication System

Due to the rapid development of small satellite technology and the advantages of low earth orbit satellite (LEO) with low delay and low propagation loss as compared with the traditional geosynchronous orbit satellite (GEO), the broadband LEO constellation satellite communication system has gradually become one of the most important hot spots in the field of satellite communications. Many countries and satellite communication companies in the world are formulating the project of broadband satellite communication system. In view of the actual demand of China, in order to construct the broadband LEO constellation satellite communication system reasonably and effectively, and to research an efficient networking scheme, it is necessary to analyse traffic demand. This paper constructs the location-based traffic model and time-based traffic model. A method to simulate the traffic of broadband LEO constellation satellite communication system is proposed. And the traffic in one satellite and one orbit of the broadband LEO constellation satellite communication system are simulated respectively by using STK and MATLAB simulation software.

Design and Transmission Performance Analysis of Satellite Constellation for Broadband LEO Constellation Satellite Communication System Based On High Elevation Angle

Because of the rapid development of small satellite technology and the advantages of low earth orbit satellite (LEO) satellites compared with traditional geosynchronous orbit satellite (GEO) satellites such as low time delay low propagation loss broadband, LEO constellation satellite communication system has gradually become one of the hot spots in the field of satellite communication. At present, many countries and satellite communication companies in the world are working on broadband satellite communication system programmes. In view of the actual needs of our country, through link computation and comparing the complexity of satellite implementation at different communication elevation angles to meet the terminal rate requirements, the assumption of constructing broadband LEO constellation satellite communication system with high elevation is put forward. The transmission characteristics of OneWeb constellation are simulated by STK and Matlab simulation software.

BAVP: Blockchain-Based Access Verification Protocol in LEO Constellation Using IBE Keys

LEO constellation has received intensive research attention in the field of satellite communication. The existing centralized authentication protocols traditionally used for MEO/GEO satellite networks cannot accommodate LEO satellites with frequent user connection switching. This paper proposes a fast and efficient access verification protocol named BAVP by combining identity-based encryption and blockchain technology. Two different key management schemes with IBE and blockchain, respectively, are investigated, which further enhance the authentication reliability and efficiency in LEO constellation. Experiments on OPNET simulation platform evaluate and demonstrate the effectiveness, reliability, and fast-switching efficiency of the proposed protocol. For LEO networks, BAVP surpasses the well-known existing solutions with significant advantages in both performance and scalability which are supported by theoretical analysis and simulation results.

A Comprehensive Evaluation Approach Based on AHP-BP Neural Network for Resource Allocation in Distributed Satellite Cluster Network

The distributed satellite cluster network (DSCN) is a novel concept in satellite communication field. Considering the dynamism and heterogeneity of the DSCN, the resource allocation algorithm must make adjustments dynamically according to the requirements of users as well as the utility and availability of the resource. This paper investigates the evaluation problem of the resource allocation utility in DSCN. Considering the heterogeneity of DSCN and the multi-dimensional of the resource, a distributed evaluation architecture and a multi-index evaluation system are constructed. To solve the multi-index evaluation problem, a comprehensive evaluation approach based on analytic hierarchy process and back-propagation (AHP-BP) neural network is proposed. Via several simulation results, we verify the effectiveness of the proposed approach.

Ant colony optimisation for the routing problem in the constellation network with node satellite constraint

In the field of satellite communication, there is a trend towards interconnecting satellites into a heterogeneous network. Inter-satellite links (ISLs) are used to transmit satellite management data, such as telemetry and telecommand data, as well as application data. The ground stations act as a management entity, which are connected with node satellites. This paper considers a routing problem with the aim of combining the satellite network with ground station management network to make integrated planning under the node satellite constraint. Based on the characteristic of the routing problem, ant colony optimisation is adopted to solve it. Two solution construction methods, i.e., the sequential method and concurrent method, are proposed. Experimental results on real data show that the concurrent ACO algorithm is better, and it can provide better data transmitting bandwidth of ISLs and save ground station management resources, which makes the algorithm suitable for real requirements.

위성망 이중화를 위한 국내 강우율 공간분포 분석

Abstract This paper proposes appropriate locations for site diversity to provide stable satellite communication service in Korea. For this pur-pose, we analyzed rainfall rate data measured by KMA for 5 years at 88 sites, and the variations of simultaneous occurrence of rainfall rate in pairs of sites using the correlation coefficient. This paper provided contour maps of the spatial ditstribution of rainfall rate corre-lation, and proposed information on the optimum sites/regions for the operation of muti-uplink satellite systems, in 4 cities which were principal in field of satellite communication in Korea.Key words: Site Diversity, Satellite Communication, Rainfall Rate, Correlation Coefficient, Correlation Map  Q“)”0•(Technical Regulation Division, National Radio Research Agency) xManuscript received September 8, 2015 ; Revised October 19, 2015 ; Accepted November 9, 2015. (ID No. 20150908-066)xCorresponding Author: Yong-Ki Kwon (e-mail: ygkwon@msip.go.kr) ⓒ Copyright The Korean Institute of Electromagnetic Engineering and Science. All Rights Reserved.

Ant Colony Optimization for the Routing Problem in the Constellation Network with Node Satellite Constraint

In the field of satellite communication, there is a trend towards interconnecting satellites into a heterogeneous network. Inter-satellite links (ISLs) are used to transmit satellite management data, such as telemetry and telecommand data, as well as application data. The ground stations act as a management entity, which are connected with node satellites. This paper considers a routing problem with the aim of combining the satellite network with ground station management network to make integrated planning under the node satellite constraint. Based on the characteristic of the routing problem, ant colony optimisation is adopted to solve it. Two solution construction methods, i.e., the sequential method and concurrent method, are proposed. Experimental results on real data show that the concurrent ACO algorithm is better, and it can provide better data transmitting bandwidth of ISLs and save ground station management resources, which makes the algorithm suitable for real requirements.

디지털 위성중계기를 이용한 간섭제거기능 설계 및 구현

광대역성과 광역성의 특징을 갖는 위성 통신은 시간과 공간에 관계없이 누구와도 통신할 수 있다는 장점이 있는 반면, 간섭신호에 항상 영향을 받을 수 있는 특징을 가지고 있다. 간섭신호는 전지역을 상대로 송수신이 가능하기에 불법 광대역 주파수원을 찾기 어렵고, 미치는 영향 또한 크다. 이런 영향성으로 인해 본 논문에서는 디지털통신위성(중계기)(상향링크 아날로그 신호를 디지털 신호로 변환하여 여러 가지 형태로 디지털 신호처리 후 지상으로 송신하는 기능을 갖는)을 이용하여 신호의 대역폭에 따라 간섭제거 임계값이 실시간 가변 처리되는 간섭제거방식을 구현하여 적용 시험한 결과를 소개한다. 이를 통해 향후 위성통신에서의 간섭제거기능에 대한 보다 나은 기능 개선 및 위성통신분야의 발전에 도움이 될 수 있는 정보를 제공할 수 있을 것을 기대한다. Broad band and wide area satellite communication has advantage that can be always communicate with anyone regardless of time and space. In the other hands, its communication quality is easy to be affected by interference signals. Due to the fact that interference signal can be transmitted from everywhere, it's hard to find the illegal source of signal and it has huge influence. In this paper, with this influence of interference signal, we introduce the interference rejection method, implementation and test result in the digital satellite communication processing the signal using variety of digital method. It will be useful information to improve the interference rejection function and also be helpful on the field of satellite communication.

The Design and Realization of a Spectrum Acquisition Unit Based on the MSP430F149 MCU

In the field of satellite communications, spectrum analyzer is one of the primary means of frequency monitoring, and it plays an important role in ensuring communication quality. According to the principle of the superheterodyne spectrum analyzer, the design and realization of a spectrum acquisition unit based on MSP430F149 MCU is given in this paper. Comparing the test results with those of the Agilent N9020 spectrum analyzer, the comparison shows that in the intermediate frequency signal monitoring, the spectrum analyzer designed in this paper has reached the current performance level of the mainstream spectrum analyzer.

The Universe will be televised: space, science, satellites and British television production, 1946–1969

This essay uses material from the British Broadcasting Corporation (BBC) archives to show how space-related technoscientific activities played a key role in the development of BBC television. The essay focuses on a crucial period when this influential cultural institution transitioned away from radio as their primary broadcast medium in the 1930s and 1940s to reluctantly embrace television in the 1950s and 1960s. Space-related activities, including astronomy, cosmology, rocketry, aerospace engineering, astrophysics and interplanetary research, played a key role in the modernization of BBC television broadcasting in two intersecting ways. Space-related material provided informative, yet popular, programmatic material that helped BBC television compete in an increasingly commercialized media market, and, later, space projects supplied technologies that impacted on the mechanics of broadcast production and transmission. The profile and prestige of space as a topic, in particular, its visuality, the drama of exploration it presented, and its association with celebrity scientists like Bernard Lovell and Fred Hoyle, meant that such programming became a crucial business asset for the BBC and a professional asset for ambitious producers who saw its commercial potential. Following the launch of Sputnik in 1957, space technology became further intertwined with the development of British broadcasting as the fields of satellite communications and broadcasting transmissions infrastructure converged. In particular, BBC producers promoted the potential development of communication satellites within their television programming by portraying such satellites as plausible and necessary for the advancement of civilization, and most crucially, as a prospective British Space Race achievement.