Computer Aided Constellation Management and Communication Satellites

The development of compact, light, high-efficiency, low-cost antennas for wireless communication systems, as well as their integration with the rest of the system, has become a tempting task. Microstrip patch antennas are a popular, low-cost design. The demand for more durable and compact patch structures is increasing as a result of satellite communication technology services. The suggested antenna displayed a return loss response of less than −10 dB starting at 6.5 GHz with a VSWR < 2. Reduced ground plane provided a good tuning parameter for return loss. The available antenna designs work at frequencies ranging from 4 to 8 GHz, making them appropriate for C-band satellite communications. This C-band satellite antenna is primarily used in military applications for speech and data communication. The design and evaluation processes were replicated using HFSS software.

This paper describes the design of a split ring resonator-based conformal antenna for Earth coverage spaceborne applications. To have a reduction in antenna size without degradation in the performance, two design techniques are included in the antenna design. First, a rectangular slot is etched from the circular radiating patch. Secondly, with a partial ground plane in the antenna design, a circular split ring resonator has been engraved. The substrate used for the projected antenna design is a flexible Rogers substrate (RO3006) having a relative permittivity of 6.15 and a thickness of 1.27 mm. The overall antenna size is 20 mm × 15 mm × 1.27 mm. Without conformal structure, the designed antenna provided a wide frequency of operation from 4.73 to 6.12 GHz, a peak gain of 1.9 dBi, and a radiation efficiency of 99.8 percent. The patch design is wrapped over a cylinder having a 10 mm radius along the y-axis to obtain the bending structure. The designed conformal antenna has an operating frequency range from 4.54 to 5.91 GHz. For Earth coverage applications and aircraft applications, the designed antenna can be used.

There is an ever-increasing requirement for smaller and more efficient satellites. Minimizing the size of satellites has its advantages. It equally imposes several challenges in bringing up the satellite from the drawing board to a flight model. This paper focuses on an antenna deployment mechanism that is being developed by a student satellite team from BMS College of Engineering. Antenna deployment mechanisms of similar class satellite programs were referred and a model has been developed and analyzed. Experiments were also conducted on a prototype model to verify the conceptual working of the mechanism.

This article presents a low cost and easy to realize payload/telemetry data transmitter for small satellite using commercial-off-the-shelf (COTS) components such as 8-bit microcontroller and FM transceiver module. 8-bit microcontroller handles the baseband modulation to generate audio signal which is then FM modulated on RF carrier frequency. The prototype model, developed using the design presented in this paper, supports data rate of 1200 baud rate using audio frequency shift keying (AFSK) at baseband and frequency modulation (FM) at radio frequency in VHF band. Since the baseband modulation is handled by 8-bit microcontroller, data rate and modulation schemes can be implemented by software, thereby making the design more flexible and reconfigurable. Moreover, since the RF front end is supported by FM transceiver, the same system can be extended to receive the tele-commands from ground in half duplex mode, provided that the baseband demodulation is handled by the microcontroller.

This paper includes a metamaterial design at THz range, explicitly useful as an absorber. It is composed of three layers with top and bottom are to be gold and separated by a dielectric material in between. The structure provides 100% at a lower frequency of 0.846 THz and 98.6% at a higher frequency of 2.12 THz. The proposed Complementary Split Ring Resonators (CSRR) shows a tuning range from 2.12 to 2.16 THz. The CSRR parameter is optimized to get dual resonance frequency. The proposed structure provides a quality factor of 19.2 at a lower band frequency and 19.56 at an upper band frequency.

The necessity for good and tenable communication systems has motivated researchers to develop mobile communication networks (MCN). On the other hand, the huge functionalities of the global system of mobile (GSM) communication have given an increasing number of users. As the subscribers grow, the necessity for efficient and productive planning of the limited frequency spectrum of the GSM is inevitable, especially in highly dense areas. Researchers have proposed various algorithms for frequency or channel allocation (CA), as the discussions about CA methods to resolve the various practical issues in CA are going on. The literature reveals that the “Manhattan distance” concept can be used in scheduling and optimization problems. Similarly, the same idea makes it possible to discover a more tenable telecommunication system with “ease of connectivity” among subscribers, even when many users are on a common channel. Graph labeling is the most interesting idea in graph theory that has numerous uses in different fields, particularly in communication networks. 2-odd labeling assigns distinct integers to the nodes of a graph \(G\left( {V,E} \right)\) such that the positive difference of adjacent nodes is either 2 or an odd integer, \(2k \pm 1,\;k \in N\). The motivation behind the development of this article is to study the applications of graph theory in communication networks through the concept of 2-odd labeling in graphs.

Blockchain, which is critical to the Satellite and other networks, has recently acquired popularity. The use of blockchain in the Satellite network, in particular, will allow the network to track and govern resource utilization and sharing more efficiently. Massive MIMO is a new technology for improving network capacity in multi-user scenarios. Paper has used a multi-user massive MIMO scenario with a spoofing attack. It examines the effects of eavesdropper spoofing pilot power and a variety of groups on the confidentiality efficacy of the systems under consideration.

In this paper, we propose a novel formulation to obtain the small SAR constellation that optimizes revisit times in the worst, average, and best scenario over a given Region of Concern (ROC). We demonstrate this formulation for selected Indian regions via detailed System Tool Kit (STK) simulations to get the optimum constellations.

This paper proposes an antenna array particularly intended for ocean radar systems. The array is made up of 16 identical elements. This antenna resonates at 10.10 GHz, and the bandwidth of antenna is 90 MHz. The elements are organized along the extended arms of a four-element one-dimensional arrangement and are feed in the middle by a number of perfect finishing touch microstrip lines. To depart from the established route, each patch element was cut with a slit to allow for horizontal polarization.

Chromatic graph theory provides “an efficient model for solving satellite scheduling problems. Modems are represented by nodes, and service requests between modems are represented by lines connecting the nodes. The underlying model is a multigraph, a graph with multiple edges between the same pair of nodes. A schedule corresponds to a line-colouring of the multigraph. Each colour represents a time slot, and lines sharing a node must be coloured differently so that a modem is not required to simultaneously participate in two different requests. A schedule exists if the number of colours used does not exceed the number of time slots in the frame and if the number of lines coloured the same colour never exceeds the number of carrier frequencies allowed”. “2-odd labelling of a graph \(G(V, E)\) with node set \(V\) is an injection ‘f’ from \(V\) to \(Z\) (the set of all integers) such that the absolute difference between the labels of the adjacent nodes, \(u\) and \(v\), is either an odd number or exactly 2. If \(G\) admits 2-odd labelling, then it is called a 2-odd graph”. In this paper, 2-odd labelling of some well-known graphs are derived, besides highlighting some interesting applications of graph labelling in satellite communication.

This work gives the comparison of different substrate materials required for designing a microstrip patch antenna, i.e., FR-4, RO4003C, Arlon DiClad and RT Duroid that operate in the frequency band of 22–30 GHz. The purpose of this work is to compare and propose a particular substrate that can be used in a patch antenna at Ka frequency band. The height of the substrate material is kept fixed at 1.6 mm for all substrates. Simulation-based comparative analysis is done on different dielectric substrate materials to evaluate the antenna metrics such as antenna input impedance, VSWR, S-parameters, gain, and radiation efficiency.

The field of graph theory, specifically graph labeling is used in communication networks, particularly in satellite communication. An allocation of numbers to the nodes of a graph \(G (V, E)\) under some conditions is a node labeling of\(G\). In a “mobile satellite service (MSS)” system, “channel using efficiency is still the main factor” because the systems frequency reuse factor cannot reach 1 exactly. So, researchers have proposed a channel reallocation method using the concept of matching theory to handle this situation by reducing the interference level. A “divisor 3-equitable labeling is a bijective such that \(\left|{e}_{d}\left(i\right)-{e}_{d}\left(j\right)\left|\le \right.1 \, \forall \; 0\le \right.\) i, j ≤ 2, where \({e}_{d}\left(i\right)\) is the count of lines labeled with i under d. A graph that accepts divisor 3-equitable labeling is called a divisor 3-equitable graph”. This article shows the “existence and non-existence of divisor 3-equitable labeling of certain graphs, besides recalling a few applications of graph labeling in communication networks”.

In this research article, an economical optical code division multiplexed (OCDMA) inter-satellite system is presented using shift zero cross correlation codes (SZCC) and polarization division multiplexing (PDM). Total capacity of 100 Gbps is achieved with ten users and communicated over 25,000 km link distance between two satellites. Effect of different distances, pointing errors at receiver and transmitter is analysed and further proposed S ZCC codes are compared with random diagonal (RD) codes in Is-OWC system. It is observed that S ZCC codes are better than RD codes because of zero cross correlation.

Internet is one of the great inventions for human kind. Everyone wants to be connected every time in this era. Real-time news or information is required for the growth of different sectors. Military, government, share-market, etc., require current information of the globe. And, all this is not possible without satellite communication. On the other side, dependency on it may be very harmful. If the frequency is blocked, then the whole system will be affected. As the new technologies may have many disadvantages, similarly satellite communications may create problems. The satellite communication has more applications and useful for the mankind and overall development of society, country, businesses, agriculture, education, health, etc.

In the present paper, a low-profile and compact H-shaped dielectric resonator antenna (DRA) is investigated. The antenna is fed using coaxial cable, which provides the required input matching and improves the radiation pattern. The proposed design engenders three frequency bands, i.e., 3.31–3.77 GHz, 4.33–5.10 GHz, and 5.17–5.46 GHz with a resonant frequency of 3.5, 4.6, and 5.3 GHz, respectively. The antenna shows an average gain of 5.4, 5.9, and 6.3 dBi in the three desired bands. As a result, proposed DRA may find useful applications in the S and C bands used by airport surveillance radar for air traffic control, weather radar, surface ship radar, satellite communication, Wi-Fi devices, cordless telephones, and some surveillance and weather radar systems.

Antenna design is a critical component of any communication system and requires to exhibit multiband operation with optimal radiation characteristics to enhance technological capabilities. Recently, CubeSat, low earth orbit satellites have emerged as a new class of satellites due to their low cost and light weight, which enable them to perform a variety of functions such as remote sensing, deep space communication research, supports mutiple mobile users and so on. Antenna design for these CubeSat applications must be compact in size while also exhibiting high gain and wide bandwidth characteristics. This article discusses eight latest antenna designs analysing various gain and bandwidth enhancement techniques to offer a comprehensive reference model for improved quality of life. This will aid and deliberate on identification and selection of relevant design specifically for satellite communication.

Hybrid combination of Amorphous-Si (a-Si) solar cells with antennas (Solants) has important use in space satellites to solve the dual purpose of transmitting and receiving electromagnetic waves while generating power. This paper describes a stacked a-Si-based solar cell which can be easily integrated with a stacked microstrip antenna thus enhancing its technological capability. The intrinsic layer (i-layer) thickness of a p-i-n solar cell is varied from 0.1 and 1 µm for space and power optimization. The optimal thickness for maximum power conversion efficiency is obtained to be 0.3 µm. After the solar cell is integrated with the antenna, it does not alter the overall structure, thereby, a lot of space is saved through the innovative technology design. This integration also provides an enhance power generation capability for dependable and enduring satellite communication.

Since 1945, when Arther C. Clarke proposed the synchronous motion of satellites with constant angular velocity in lockstep with the earth’s rotation, satellite communication has been a reality. Satellite communications have recently experienced a renaissance in popularity, owing to advancements in technology and private investment. These findings will aid in the direction of future satellite communication research. Onboard processing and data collection are just a few of the primary drivers of innovation while earth observation, and aviation and maritime tracking and communication are few add on area of research applications. The following five axes are discussed in detail: the origins of satellite communication, the components of a satellite link, the advantages and disadvantages of satellite communication, frequency allocation, and the current situation.

Like many other wireless communication systems, the spectrum of satellite communication is also overcrowding day by day due to the fast adoption of multimedia applications, on-demand broadband communication, and related interactive services. Therefore, new communication paradigms are being explored for optimum spectrum utilization. In this regard, cognitive satellite communication has recently gained much interest in the research community. In this paper, the basic notion of satellite cognitive-communication and its practical implementation of hybrid/dual cognitive satellite systems are reviewed. Furthermore, a systematic review of various techniques for spectrum access is presented for dual satellite systems. In addition to that, several challenges associated with the applicability and deployment of cognitive radio over SatCom in the identified scenarios are presented and concluded the work by providing insights into the various open research issues in this domain.

The article discusses an efficient method for digital beamforming toward transmission of signals having large bandwidth. Conventional digital beamforming techniques offer hardware efficient solution when compared to active arrays implemented using analog microwave phase-shifter modules. However, these techniques exhibit an inherent limitation while signals having large bandwidth are under consideration. The article discusses a methodology to overcome this constraint. By resolving the wideband signal into its constituent frequency sub-bands and subsequently computing the phase-shifts based on the center frequency of the sub-bands, it is shown that the radiation pattern of the active antenna can be improved. The article compares the results obtained by simulating a wideband signal transmission using a uniform linear array adopting the conventional approach as well as sub-banding. The approach has several applications including space-based data transmission.

Nowadays, everyone uses Internet, do financial transactions and many other day-to-day activities. As the users are becoming more and more aware of the privacy, data security had become a prime concern. Quantum Internet inspires to be a possible solution. Quantum Internet uses quantum key distribution to provide security by generating symmetric keys for the data transfer. Newly developed technologies and manufacturing processes paved way for designing and development of small satellites. Small satellites can be launched in forms of clusters at a marginal cost of launching large communication satellites. Here, we review the basic concepts of quantum key distribution. Its application in satellite communication specifically using CubeSat satellites. We also touch upon the recent development in the field of satellite-based QKD systems. A brief on the major milestones and important small satellite mission is also presented. Further, we present a comparison study between the prominent QKD algorithms pertaining to their application in satellite-based QKD systems. We conclude the article with discussion on the applications, advantages and disadvantages of using QKD on satellite-based communication networks, further extending it from local area networks to worldwide Internet.