Inter-satellite Optical Communication Research Articles

Analysis of Inter-Satellite Optical Wireless Communication Systems for Enhanced Data Transmission in Satellite Constellations

Analysis of Inter-Satellite Optical Wireless Communication Systems for Enhanced Data Transmission in Satellite Constellations

A robust and precise centroid positioning method for the weak beacon spot in long-distance inter-satellite optical wireless communications.

The centroid estimation of the beacon spot is crucial to the pointing, acquisition, and tracking subsystem in inter-satellite optical wireless communication (IsOWC), especially for the received very weak beacon caused by a long link distance. In this work, we propose an accurate centroid positioning method to calculate the centroid of such a weak beacon with a low peak signal-to-noise ratio. The proposed method is based on the idea that uses the normalized amplitude of the gray gradient to enhance the weights near the center of the beacon spot. Both comparative numerical simulation and experimental verification are implemented, which demonstrate the effectiveness and feasibility of the proposed method. Compared to the gray centroid method, interpolation-based method, Hough transform method, and Gaussian fitting method, the proposed method has stronger robustness and higher accuracy, which could be helpful to applications in IsOWC as well as beacon-based pointing and tracking systems.

Ultra-long haul high speed 96 × 40 GB/s radio over IsOWC system employing advanced modulation scheme

Abstract This paper successfully demonstrates that point-to-point (P2P) superdense wavelength division multiplexing (SDWDM) based on the radio over intersatellite optical wireless communication (Ro-IsOWC) system of 96 channels separated by a 100 GHz bandwidth with 40 GB/s data rate on each stream at a 10,000 km link range has been designed and investigated. The performance of the proposed work has been evaluated by considering the comparison of advanced modulation schemes such as carrier-suppressed return-to-zero (CSRZ), duobinary return-to-zero (DRZ), and modified duobinary return-to-zero (MDRZ) with an optical preamplifier on the bases of bit error rate (BER), quality factor, eye height, and optical signal-to-noise ratio (OSNR) in the clear weather condition. Moreover, the effects of internal parameters such as transceiver aperture diameter and gain of an optical amplifier also have been analyzed with an optimized modulated system. Apart from this, the system performance also has been assessed under varying data rates and OWC frequency ranges with the best-suited modulation format. It has been found that the CSRZ modulation format has shown robust performance and can achieve BER as better as 10−09 with a 5.5 dB quality factor for all wavelengths. It also has been observed that the quality of the received signal deteriorates below an unacceptable value for data rate and link distance beyond 40 GB/s and 10,000 km, respectively.

Design and comparative analysis of Inter Satellite - optical wireless communication (IS-OWC) for Return to Zero (RZ) & Non-Return to Zero (NRZ) Modulation formats Through channel diversity

IS-OWC (Inter Satellite Optical Wireless Communication) is a novel method of establishing interconnection between two satellites. Inter-satellite Optical Wireless Communication is concerned with the use of lasers instead of traditional radio and microwave systems for wireless optical communication. When compared to a single channel, the channel diversity strategy produces better results. The IS-OWC device uses a diversity technique in which several signal paths are available, allowing the Q-factor and signal intensity to be extended or increased over a large distance. In this paper, the Q-factor and the Bit Error Rate (BER) are analyzed with diverse modulation formats like Return to Zero (RZ) and Non-Return to Zero (NRZ) using the channel diversity technique.

Design and analysis of a piezo-actuated 2-DOF high-precision parallel pointing mechanism capable of carrying a heavy load

This paper presents the design, modeling, analysis, and test of a 2-degree-of-freedom (2-DOF) high-precision parallel pointing mechanism capable of carrying a heavy load up to 30 N⋅m driven by high voltage piezo-stack actuators (HVPSAs). The proposed pointing mechanism, which employs flexure hinges as joints, provides two tilting degrees of freedom and can be utilized for intersatellite optical communication, remote sensing satellite lens pointing, and other engineering fields requiring large load capability. In this paper different kinds of flexure hinges are utilized to achieve the desired motion and working performance. With consideration of most compliant elements, Castigliano’s second theorem was adopted to establish the analytical static model of the mechanism, which was then validated by FEA simulation and experimental testing. Finally, a high-precision pointing prototype is fabricated and a series of motion performance tests have been implemented, which validated the feasibility of the proposed system. The superiority of the proposed design is that it possesses large load capacity as well as excellent pointing performance simultaneously, while the former characteristic was infrequently reported in previous works.

Designing of high-speed inter-satellite optical wireless communication (IsOWC) system incorporating multilevel 3-D orthogonal modulation scheme

Designing of high-speed inter-satellite optical wireless communication (IsOWC) system incorporating multilevel 3-D orthogonal modulation scheme

A multichannel Hermite Gaussian (HG) intensity profiles based inter-satellite optical wireless communication (IsOWC) using transmitter diversity

A multichannel Hermite Gaussian (HG) intensity profiles based inter-satellite optical wireless communication (IsOWC) using transmitter diversity

A reach enhanced hybrid OCDMA-MDM multiplexing based IsOWC system incorporating EDFA, SOA, and RFA

Abstract Reach enhancement in inter-satellite optical wireless communication systems (IsOWC) is an utmost requirement due to ever-increasing internet usage all over the globe. Optical code division multiplexing is prominently incorporated for security enhancement in IsOWC systems, however, limited in terms of total reach. Therefore, in this work, a 120 Gbps capacity-based hybrid OCDMA and mode division multiplexed (MDM) IsOWC is presented using different optical amplifiers such as semiconductor optical amplifier (SOA), erbium-doped fiber amplifier (EDFA), and Raman fiber amplifier (RFA). Moreover, the combined effects of Laguerre–Gaussian (LG) with EDFA/SOA/RFA and Hermite–Gaussian (HG) modes with EDFA/SOA/RFA amplifiers are investigated. Results revealed that the proposed system can cover 5000 km IsOWC link within acceptable BER limits and EDFA with LG modes is found to be the best technique.

A high-speed multi input multi output Ro-IsOWC system incorporating Manchester coding and E-LP, O-LP modes

Abstract Aiming at the link length enhancement in intersatellite optical wireless communication (IsOWC) system, considering the hybrid radiofrequency (RF)-enabled multi input multi output (MIMO) system, we accentuate the realization of medium earth orbit (MEO)-based IsOWC system by incorporating different modulation formats such as return to zero (RZ), non-RZ (NRZ), and Manchester coding. A 40 Gbps and 16 × 8 MIMO system enabling 40 GHz RF signal is proposed by using even linear polarized (E-LP) mode, and odd linear polarized (O-LP) mode over a 22,000 km IsOWC channel. Further, a performance comparison of NRZ, RZ, and Manchester coding is performed at different IsOWC distances in terms of the Q factor. Results revealed that the proposed system with Manchester coding and O-LP mode can successfully cover the 22,000 km IsOWC link length by exhibiting a 6.35 Q factor value.

Performance analysis of 2λ × 160 Gbps optical single sideband (OSSB) generation in polarization division multiplexed (PDM) QPSK based satellite wireless optical systems (SWOS)

Abstract Capacity enhancement in satellite wireless optical systems (SWOS) systems is an ultimate task to accomplish due to ever-increasing internet services and it can be achieved by incorporating polarization division multiplexed (PDM) quadrature phase shift keying (PDM-QPSK). Herein, 2λ × 160 Gbps intersatellite optical wireless communication (IsOWC) system is proposed using PDM-QPSK. Spectral efficiency is prime requirement to enhance the performance of system and therefore, a suppression of optical single sideband (OSSB) in PDM-QPSK carrier spectrum is performed by employing fiber Bragg grating with 0.99 reflectivity. Proposed system is investigated in terms of log BER and error vector magnitude percentage (EVMP) at varied SWOS distances. Further, effects of the digital signal processing (DSP) in the receiver are analyzed by considering and neglecting the module. Results revealed that suppression of sidebands and employment of DSP enhance the system performance and competent to cover 52,000 km SWOS distance.

Steering Toward the Future: The Use of Piezo Technology for Optical Intersatellite Communication

Recent years have seen a reemergence of interest and investment in low Earth orbit (LEO) satellite constellations. First proposed in the 1990s, the construction of such constellations was once the hopeful plan of companies, such as Iridium, Globalstar, Odyssey, and Teledesic [1]. Unfortunately, most of these plans never fully came to fruition as the upfront construction costs were unfeasible, and a new competing network implementing fiber optic cables was introduced. These fiber optic cable networks promised users high data rates at a fraction of the construction costs of a satellite network. Today, as worldwide data throughput and coverage requirements increase beyond the capacity of fiber optic cable networks, companies, such as SpaceX, Amazon, ViaSat, OneWeb, and Telesat, are resurrecting the idea of LEO constellations [2]. In order to avoid the fate of their predecessors, these companies must build robust constellations with reliable satellites as launching satellites comes at high costs. One of the most critical systems aboard these satellites is the communication terminal that allows each satellite to communicate with other satellites in the constellation.

Inter-satellite optical wireless communication (IsOWC) systems challenges and applications: a comprehensive review

Abstract Satellite communication, in over half a century have attained remarkable breakthrough in high speed transmission. These innovations, on the other hand, have come in tandem with significant performance improvements in other IT and telecommunications systems. As a result, these significant benefits are not as visible to the broader public as they would be as if this burst of performance had occurred in isolation. In nutshell, space satellite communication using optical technology provide powerful alternative to radio frequency (RF) and make communication reliable and cost effective. Satellite communications systems allow a whole new race of civilian and defence operations in surveillance, telecommunications, object tracking and space exploration. Since independent satellites are restricted by volume, space and strength, small satellites production in bulk clusters may be effective for a range of wildfire monitoring, science missions, mapping in gravity and water management exploration, among others. The development of communications satellites would provide for a more comprehensive understanding of the near-earth environment as well as a more efficient and cost-effective way of reaching space, thanks to the utilisation of multi-satellite systems. As a result, when satellites are designing, IsOWC is an utmost point to be considered. The numerous researches being performed in the satellite communications for introducing multi communications based on different orbits are described in this study. IsOWC systems over radio frequency based communication are preferred due to large bandwidth, high speed, absence of electromagnetic interference (EMI), lower transmission losses and improved security. We also present a detailed listing of challenges in Is-OWC such as Doppler shift, point ahead angle, satellite vibration and tracking, acquisition tracking and pointing (ATP) and background noise sources.

Terabyte capacity-enabled (10 x 400 Gbps) Is-OWC system for long-haul communication by incorporating dual polarization quadrature phase shift key and mode division multiplexing scheme

Inter-satellite optical wireless communication (Is-OWC) links can become promising solutions to realize the next-generation high-speed communication services. The operation of Global Navigation Satellite Systems can be improved with the use of Is-OWC links through ranging and communication services. However, the key challenge in Inter-satellite link (ISL) is its effective range which is limited due to pointing errors. In this work, we propose to develop a high-capacity and long-reach Is-OWC link by incorporating hybrid mode division multiplexing (MDM) and wavelength division multiplexing (WDM) schemes to transmit ten independent channels over 40000kms Is-OWC link. Each channel is capable of carrying 400Gbps data which is encoded by the dual polarization quadrature phase shift key technique with required signal to noise ratio (SNR) and received power. The proposed Is-OWC link satisfies the enhanced communication within Geostationary Earth Orbit (GEO) and Low Earth Orbit (LEO) satellites. The proposed Is-OWC is further evaluated under the impact of space turbulences, particularly transmitter and receiver pointing errors. The result reported that the proposed Is-OWC link can transmit 4Tbps data over 16000kms with the transmitter pointing error of 2μrad and receiver pointing error of 1μrad.

Induced electron radiation effect on the performance of inter-satellite optical wireless communication.

This paper provides the details of a study on the effects of electron radiation on the Performance of Inters-satellite Optical Wireless Communication (IsOWC). Academia and industry focus on solutions that can improve performance and reduce the cost of IsWOC systems. Spacecraft, space stations, satellites, and astronauts are exposed to an increased level of radiation when in space, so it is essential to evaluate the risks and performance effects associated with extended radiation exposures in missions and space travel in general. This investigation focuses on LEO, especially in the near-equatorial radiation environment. Radiation experiments supported with simulations have made it possible to obtain and evaluate the electron radiation impact on optoelectronics at the device level and system level performances. The electron radiation has induced a system degradation of 70%. This result demonstrates the importance of such an investigation to predict and take necessary and suitable reliable quality service for future space missions.

State of research and development of small spacecraft with optical communication

The current state of scientific and technical research and development of small space vehicles using optical communication systems is considered. The problems standing in the way of creating intersatellite optical communication are discussed as well as the mutual position of satellites determination and it tracking. Scientific tasks for the implementation of the development of an optimal reliable control system for satellite communication are defined.

Performance optimization of an intersatellite optical wireless system using linearly polarized modes

Modern optical communication has advanced from the use of merely lengthy optical fibers to using features of the powerful wireless system and optics resulting in the use of lasers to transmit data at a much greater rate. This gave way to the optical wireless communication system growing roots into space communications. In this work, an intersatellite optical wireless communication link has been analyzed for studying the performance of the system considering linearly polarized modes. The link performance has been investigated in terms of the quality factor (Q factor) as a function of the transmission wavelength, detector type, data rate, distance, transmitter aperture diameter, and pointing error angle. The optimized results of the system reveal that the LP01 mode performs better with the non-return-to-zero modulation scheme at the 850 nm wavelength using a PIN photodiode.

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.

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.

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