Inter-satellite Communication Research Articles

FL-QKD based on optical-THz biphotons generated by spontaneous parametric downconversion in inter-satellite wireless communication: publisher's note.

This publisher's note serves to identify a correction in Appl. Opt.60, 7362 (2021)APOPAI0003-693510.1364/AO.430898.

FL-QKD based on optical-THz biphotons generated by spontaneous parametric downconversion in inter-satellite wireless communication.

Floodlight quantum key distribution (FL-QKD) is a new QKD protocol that can achieve a 2 Gbps secret key rate (SKR) in a 50 km fiber link without multiplexing technology [Q. Zhuang et al., Phys. Rev. A94, 012322 (2016)PLRAAN1050-294710.1103/PhysRevA.94.012322]. In this paper, we propose a wireless FL-QKD at terahertz bands (THz-FL-QKD) in inter-satellite links. THz-FL-QKD is the two-way protocol that sends quantum signals in the forward channel, modulates and amplifies the received signals at the receiver, and then returns to the transmitter through the backward channel for homodyne detection and decoding. We analyze the security of THz-FL-QKD against individual attacks and optimum collective attacks. Numerical simulations show that THz-FL-QKD is capable of a 50 Mbps SKR at 10 THz frequency in a 200 km inter-satellite wireless link. We expect this work will provide an efficient path to build a high-speed global quantum communication network.

Performance Analysis and Evaluation of Inter-Satellite Optical Wireless Communication System (IsOWC) from GEO to LEO at Range 45000 km

The importance of free-space optical (FSO) communication has increased during the last decade, introducing its unique features such as its high data rate, license-free spectrum, ease of deployability, and low power consumption. In the future, communication between low earth orbit (LEO) and geostationary earth orbit (GEO) satellites will be commonly established by using inter-satellite optical wireless communication (IsOWC) systems. That enables GEO satellites to relay information to and from LEO satellites and fixed Earth stations that otherwise cannot transmit/receive data permanently. IsOWC systems are the most effective application of the FSO, and they will be favorited shortly because of their features. In this work, we established an IsOWC between GEO and LEO satellites at a distance of 45000 km to achieve a target bit error rate (BER) equal to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−6</sup> . Furthermore, we proposed an IsOWC system with suitable operating wavelengths. Physical techniques such as the multi-input multi-output (MIMO) technique and a wave division multiplexing (WDM) technique are employed.

Multicarrier Multiplexing Continuous-Variable Quantum Key Distribution at Terahertz Bands Under Indoor Environment and in Inter-Satellite Links Communication

We propose a continuous-variable quantum key distribution (CVQKD) scheme at terahertz (THz) bands based on multicarrier multiplexing (MCM) technology. In this scheme, multiple Gaussian modulated subcarriers are coupled to transmit multipath superposed thermal Gaussian states. At the receiver, optical discrete Fourier transform (ODFT) is used to demultiplex the received subcarriers, and the keys can be generated in parallel by homodyne detection and post processing. We analyze the security of the scheme against the optimal collective Gaussian attack under indoor environment and in inter-satellite links respectively. Results indicate that by using MCM technology, each subchannel may be affected by crosstalk, resulting in slight shortening of the maximal transmission distance while the total secret key rate can be greatly increased. We also verify the feasibility of higher key rate and longer distance THz-QKD by using MCM technology in inter-satellite links communication. We expect this work will provide an efficient path to build a global quantum communication network.

Numerical comparison between DPSK 33, DPSK 66 and duo binary in WOC system

OWC systems have turned into a state-of-the-art technology because of their superior performance uniqueness and its innumerable characteristic as compared to its RF. One of the OWC application is inter-satellite wireless optical communication (Is-WOC), this framework can be improved by using different ways such as advanced modulation formats and aperture diameter. We demonstrate an analysis based on the aperture diameter effect in transmission of single channel with 40 Gb/s Is-WOC system using three different modulation methods, differential phase-shift keying (DPSK) with a duty ratio to 66% and 33% and duobinary. Choosing these three modulations from various modulation format is done depending on the advantage they provide where the DPSK gives to fiber nonlinearity a powerful robustness and less susceptible to SPM and XPM and for system requirements of dispersion compensation in duobinary, it provides higher chromatic dispersion tolerance mitigate. The result shows the effect of different transmitter aperture diameter (from 2 to 20 cm) for a constant distance 200 km accomplished by quality factor and minimum BER. We conclude there is a great loss in the small aperture diameter, even in the presence of best modulation format, therefore as the aperture diameter increase the Q-factor increase, but some increased rise is linear and the other is changing from linear to non-linear in a fixed Q-factor point equal to 5.63.

BeiDou satellites cross-regional communication path assignment model and resource management

Time division inter-satellite communication and ranging link assignment of BeiDou satellites have made important progress; however, there is still the unsolved issue of integrated communication between ground gateway, aircraft, or even ship, and the BeiDou satellites. Therefore, in this study, we develop a path assignment model based on the idea of clustering and Markov chain. The optimal path is determined by the objective function based on the maximum transition probability. The transition probability takes into account the communication environment, congestion status, aircraft mobility, and reduces the complexity of path assignment by hiding the topology in the region. At the same time, due to the limited resources of onboard computing, storage and bandwidth, we also design a resource management strategy based on task urgency, aimed at minimizing the unreasonable allocation index, to enable the readjustment of link application resources. Finally, the performance of the model and the strategy in average link handover times, link reliability, resource allocation fairness, and network quality of service is determined by simulation.

Pattern Reconfigurable Antenna for Formation Flying Missions

In this paper, an innovative compact pattern reconfigurable antenna is proposed and developed to establish an inter-satellite communication link between the Formation flying spacecraft. The reconfigurable beam switching antenna comprises a driven Monopole at the center, encompassed with four Reconfigurable Selective Reflectors (RSR) which act as RF radiators and reflectors for different switching conditions. PIN diodes are used to electronically control the switch states of RSR and beam switching is achieved with uniform gain along the azimuth plane without affecting the antenna’s overall performance. The peculiar demands of Formation Flying Mission (FFM) satellites such as small size and low power for communication system are resolved by the proposed technique where a single antenna with different patterns communicates with multiple satellites reducing the antenna space and power consumption. Furthermore, it also offers a solution to the problem encountered in existing FFM antenna, like microstrip patch, which serves only one satellite at a time. The antenna is designed at 2.45GHz center frequency. Simulated results show good impedance matching and performance with 13 to 15% bandwidth and wide beamwidth. The experimental validation shows that the simulation results of the antenna agree well with the measured results.

Space debris detection over intersatellite communication signals

In this paper, we apply a space-borne radar and communications (SBRC) concept for detecting space debris over signals that are designed solely for communication purposes. By using a hidden capability of intersatellite communications signals to act as a radar signal as well, we propose a new approach for debris detection that can be used to address the challenges of long-distance and ground-based detection without introducing a separate space-borne radar infrastructure. The performance of the proposed SBRC approach is evaluated from the two timely perspectives in emerging satellite communications, i.e. high-density constellations and 5G satellites. Several new findings are discovered and demonstrated via sophisticated simulations. These include the effect of system-level cooperation gain in small debris detection and link-level estimation of high-velocity debris motion.

Performance investigation of spectral-efficient high-speed inter-satellite optical wireless communication link incorporating polarization division multiplexing

Space information transmission links are crucial for covering the entire globe for communication purposes. The traditional microwave frequency-based satellite communication links have high latency and low information transmission rates. In the last few years, inter-satellite optical wireless communication (IsOWC) technology has evolved significantly as a result of its numerous benefits like wide channel bandwidth, high-speed links, and low mass and power requirements. Different research groups have proposed IsOWC links based on conventional on–off modulation schemes for transmitting 10 Gbps data between satellites separated in space. But the future generation transmission links require higher spectral efficiency and data rates with longer transmission reach. In this research, a novel single-channel spectrum-efficient 160 Gbps polarization division multiplexing-based IsOWC link is investigated for long communication range transmission. In this design, coherent detection technique is employed to mitigate the effects of system errors and space turbulence (i.e. pointing errors). A digital signal processing module has been proposed for minimizing the information signal degradation due to space turbulences and to estimate the carrier phase of the signal received. The results show that 160 Gbps information is successfully transmitted over 20,000 km range with an acceptable bit error rate (BER). Also, the influence of different system parameters including pointing error angle, receiver aperture diameter, and additional losses on the signal BER is numerically investigated.

Beacon correction method for inter-satellite laser communication

Positioning errors are caused by wavefront distortion owing to the thermal deformation of optical systems. To address this issue, we propose a restoration algorithm to correct for the beacon centroid, which is important for inter-satellite laser communication links. Based on the far-field distribution model of the distortion facula, the objective function is established to solve the wavefront distortion for reducing the pointing error of the optical communication system. The feasibility of this approach is verified by theoretical analysis and experimental verification, including in-orbit experimental verification. The proposed approach is likely to be useful for designing inter-satellite laser communication systems.

Architecting an MBSE Black-Box System Model for the Physical Layer of a Visible Light Intersatellite Communication System

Fast and reliable high-speed intersatellite communication (ISC) between small satellites is dependent on the physical layer (PL) design of the onboard communication system. However, as with nonlegacy systems, the lack of architecture and design information pertaining to the development of the PL of an LED-based visible light communication (VLC) system for ISC poses significant challenges to architecting the communication system. Addressing these challenges requires a holistic approach to the specification of the system design. To this end, we explore the use of model-based systems engineering (MBSE) principles in mitigating the design complexity of the PL architecture for the VLC system. Design concerns and gaps are addressed by developing an executable black-box system model that specifies the conceptual architecture of the system, and a parametric model that analyzes multiple system configurations based on generated values for the signal-to-noise ratio and bit error rate parameters. We utilize the structural, behavioral, and parametric semantics of SysML to define, specify, visualize, and analyze the various system design configurations. The resulting PL black-box system specification is verified through model execution.

High-sensitivity inter-satellite optical communications using chip-scale LED and single-photon detector hardware

Small satellites have challenging size weight and power requirements for communications modules, which we address here by using chip-scale light-emitting diode (LED) transmitters and single-photon avalanche diode receivers. Data rates of 100 Mb/s have been demonstrated at a sensitivity of -55.2 dBm, and simulations with supporting experimental work indicate ranges in excess of 1 km are feasible with a directional gain of up to 52 dBi and comparatively modest pointing requirements. A 750 m, 20 Mb/s link using a single micro-LED has been demonstrated experimentally. The low electrical power requirements and compact, semiconductor nature of these devices offer high data rate, high sensitivity communications for small satellite platforms.

Investigation and analysis of inter-satellite- optical wireless communication system based on dense-wavelength-division multiple-access

Optical wireless communication offers high data rates applications due to license-free and wide-bandwidth access techniques and cost-effective implementations. Recently, the world introduced to a revolutionary technology called Inter-satellite optical communication that aims to establish transmission among satellites. However, transmitting pointing errors is the main issue in creating an inter-satellite link, which leads turbulences in the connection. This article aims to study the implementation of an optical wireless communication system in satellite communication. In this work, we investigate and analysis of data rate of 16-channel in inter-satellite optical wireless communication systems (Is-OWC) based on dense-wavelength-division multiple-access (DWDM) with standard downlink channel spacing DWDM (ITU grid specification). Computer simulations are carried using Opti-system over different wavelengths between two satellites transmit 160 Gbps over 7000 km. This evaluation performance is based on eye diagrams, BER, optical spectrum and Q-Factor with minimum input power under turbulences of transmitter pointing error angle

Investigation and analysis of inter-satellite- optical wireless communication system based on dense-wavelength-division multiple-access

Optical wireless communication offers high data rates applications due to license-free and wide-bandwidth access techniques and cost-effective implementations. Recently, the world introduced to a revolutionary technology called Inter-satellite optical communication that aims to establish transmission among satellites. However, transmitting pointing errors is the main issue in creating an inter-satellite link, which leads turbulences in the connection. This article aims to study the implementation of an optical wireless communication system in satellite communication. In this work, we investigate and analysis of data rate of 16-channel in inter-satellite optical wireless communication systems (Is-OWC) based on dense-wavelength-division multiple-access (DWDM) with standard downlink channel spacing DWDM (ITU grid specification). Computer simulations are carried using Opti-system over different wavelengths between two satellites transmit 160 Gbps over 7000 km. This evaluation performance is based on eye diagrams, BER, optical spectrum and Q-Factor with minimum input power under turbulences of transmitter pointing error angle

Design of LEO Constellations with Inter-satellite Connects Based on the Performance Evaluation of the Three Constellations SpaceX, OneWeb and Telesat

The idea of designing LEO’s satellite constellations has become very important for internet access. Several LEO satellite constellations have been designed and used for global communications. In this paper, by examining three LEO satellite constellations, namely SpaceX’s 4425 satellites Ku-Kaband system, OneWeb’s 720 satellites Ku-Ka-band system, Telesat’s 117 satellites Ka-band system. And evaluating the power of data transmission and their telecommunications, we come close to a conceptual design area. First with the mathematical modeling and formulation and the design of inter-orbital communications for satellites, intersatellite communications, inter-orbital communications, we get a complete design based on the genetic algorithm for LEO satellite constellation design. And then, using simulations and design software, the final results of the designed model are obtained. Finally, we compare the results of the designed model with other existing LEO satellite constellations.

LED-Based Visible Light Intersatellite Communication for Distributed Space Systems

Intersatellite communication (ISC), also known as intersatellite links (ISLs), comes with many benefits to distributed space systems (DSSs) including advanced capabilities, such as relative navigation among small satellites and a reduction in the need for the ground segment. Radio frequency (RF) has been the de-facto method for ISC in DSS missions. However, as new science missions evolve with advanced payloads and complex architectures, RF may not be able to meet the ISC requirements of high bandwidth and throughput without violating the size, mass, power, and cost (SMaP-C) constraints of small satellites. Laser communication has the potential of meeting the requirements for these more complex missions but may violate the constraints imposed on small satellites due to its high-precision pointing and tracking requirements. This work presents the progress made on the development of LED-based visible light ISC (VL-ISC). Key aspects of the system design are presented with regards to the physical and data link layers. The simulation of the nonorthogonal multiple-access scheme for VL-ISC in a cluster of small satellites indicates an overall system throughput sum rate of about 2 Mbit/s (for system bandwidth of 0.5 MHz) among others. The roadmap to the development of a future VL-ISC standard is discussed.

Satellite platform vibration influence on acquisition system for intersatellite optical communications

Accurate pointing, acquisition and tracking systems are an important part of maintaining stable intersatellite optical communications links. Satellite platform vibration causes system instability and reduces the system precision during the building and maintaining satellite optical communication system. This manuscript studies the satellite platform vibration influence on acquisition system for intersatellite optical communications. Considering the scan parameters and platform vibration, an approximately analytical expression of scan lost possibility (SLP) is derived through newly models for acquisition analysis. Taken scanning restricted condition and SLP into account, vibration influence on the acquisition time of single-scan and multi-scan is also presented. And the theoretical result calculated by the proposed analytical expression is approximately to the result by Monte Carlo simulation.

Performance Analysis of Inter-satellite Optical Wireless Communication (IsOWC) System with Multiple Transmitters/Receivers

The satellite communications networks have certainly been innovated recently by Inter-satellite optical wireless communication (IsOWC) networks. The prerequisite for next generation mobile satellite communication is superior multimedia facility for consumers at anytime and anywhere. The proposed optical communication system is designed and analysed to improve data transmission quality over the distance between two geostationary (GEO) satellites greater than 36000 km. This trend is to achieve high speed transmission with minimizing the presence possibility of free space loss in transmission that can occur in satellite communication via the longest range. Numerous transceivers IsOWC is a hopeful way to deal with be utilized related to different earth stations as a system utilized between the geosynchronous satellites. The wireless transmission creates the opportunity at high optical power without free space loss. The results of the simulated system showed that with 32 transmitters/receivers IsOWC, the Q-factor values of 36.526, 12.176 and 4.015 are obtained at 38000 km range at laser power of (19, 14 and 9) dBm, respectively. The proposed system is operated at 19 dBm optical power and different values of aperture size and the best values of Q-factor and BER are 41 and 10−250, respectively, for highest diameter value of 20 cm. The operation of the system with various values of bit rate is verified as well. It is seen that the best system performance is at 0.032 Gb/s bit rate and will be of lower as the bit rate increases until it roughly fixes at 32 Gb/s. This research offers the treatment for the transmission problem for ultra-speed application in mobile satellite systems.

Research on simulation methods for Doppler frequency shift of a coherent inter-satellite laser link in a ground test system

Spatial Doppler frequency shift occurs during ground integration testing of an inter-satellite laser communication link and is difficult to simulate it consistently; therefore, to address this problem, a Doppler frequency shift simulation method for an optical communication carrier in space based on a dual-parallel Mach–Zehnder modulator (DP-MZM) is proposed. By adjusting the RF signal added to the MZM and the bias voltage of the DP-MZM, the output carrier suppresses single-sideband modulation to achieve a controllable optical carrier frequency shift. In this study, theoretical analysis and experimental research on this simulation method was performed, and a Doppler frequency shift simulator for ground testing of two laser communication terminals was developed, which can realize controllable optical carrier frequency shift adjustment in the range of at least ±18 GHz and a sideband rejection ratio that is greater than 40 dB. The research results have been applied to an inter-satellite laser link ground test, obtaining good simulation and test results.

Performance Evaluation Indicators of Space Dynamic Networks under Broadcast Mechanism

Large-scale heterogeneous constellations will be the major forms of future space-based systems, and the implementation of numerous derived applications depends mainly on intersatellite communication. The nodes representing heterogeneous satellites will form the networks with rapidly changing topology. However, few researches have been carried out for such networks. This paper studies the broadcast mechanism for space dynamic networks and establishes centralized and distributed routing framework. And then, performance evaluation indicators are proposed to evaluate both the connectivity of dynamic networks and the effectiveness of routing algorithms. Finally, we examine the performance of multigroup networks and verify the rationality of corresponding indicators. We also explore the impact of information survival time which directly affects the delivery ratio and, if unfortunately, may waste the communication resources. Empirical conclusion about the survival time is given in the final part. We believe the performance indicators and the routing algorithms proposed in this paper are great help to future space-based system and both the broadcast mechanism designing.