Inter-satellite Optical Communication Research Articles

Design of a Standardized Inter Satellite Optical Wireless Communication (IsOWC) System with Minimum Input Power

This paper proposes a novel method for low power communication between two Low Earth Orbiting satellites. The IsOWC system is designed for minimum input power of 27.02 dBm and -7.6 dBm, at 2.5Gbps. A standardized system for a distance of 5000km and wavelength 1550nm is designed and its performance is analysed by varying the modulation schemes and filters. A Square root (SQRT) transfer function module (SRm) is used to compensate the square-law characteristic of the photodiode. By using SRm in the system 67% increment in system efficiency is observed. The optimized performance is obtained by using NRZ scheme and Bessel filter. Highest Q factor of 6.70dB and 6.72dB are obtained for simulation with NRZ scheme and Bessel filter respectively, with minimum BER 10-12.

Investigations on 16x16 multiple Tx/Rx in IsOWC using IM/DD and CO-QPSK schemes

The intersatellite optical wireless communication (IsOWC) is used because higher data rates for longer distances can be achieved with minimum time delay. The analysis of 16x16 multiple Tx/Rx system using IM/DD and CO-QPSK techniques is done and from simulations, it is observed that maximum achievable distance of IsOWC link is a function of bit rates. For the transmission of data at longer distances, data rates should be low. The results of simulation for comparison between the two techniques in ISOWC system model are presented and discussed.

Modification in Parameters and Improved Analysis of Intersatellite Optical Wireless Communication System

Modification in Parameters and Improved Analysis of Intersatellite Optical Wireless Communication System

Prediction of ionizing radiation effects induced performance degradation in homodyne BPSK based inter-satellite optical communication systems

Ionizing radiation effects induced on-orbit performance degradation in homodyne binary phase shift keying (BPSK) based inter-satellite optical communication system is predicted in this paper. Essential optoelectronic devices involved in optical communication system were irradiated by Co60 gamma ray and ionizing radiation environment of three general orbits was analyzed. On this basis, variations of terminal performance loss and system BER degradation along with on-orbit working time were simulated. Influences of terminal location and orbit environment were further discussed. Radiation protection on laser transmitters requires more strengthening, especially for those located in MEO and GEO satellites.

Performance degradation of QAM based inter-satellite optical communication system under gamma irradiation

Main devices in quadrature amplitude modulation (QAM) based inter-satellite optical communication system were irradiated to a total dose of 20krad with the dose rate of 5rad/s using a Co60 radiation source. Gamma irradiation impacts on devices were analyzed and on the basis, system performance degradation was simulated. Variety of system BER along with onboard working time for different inter-satellite links was presented. In addition, some adaption methods were proposed to reduce gamma irradiation induced degradation.

Gamma radiation impact on performance of OOK, DPSK and homodyne BPSK based optical inter-satellite communication system

Performance of optical inter-satellite communication system is influenced by the harsh space radiation environment. Gamma radiation effects on main devices of communication system are analyzed and on the basis of existing experimental data, performance degradation of on off keying (OOK), differential phase shift keying (DPSK) and homodyne binary phase shift keying (BPSK) based system under 1kGy gamma irradiation is simulated. Variation of Q factors and bit error ratio of these systems with different radiation position are achieved and discussed. The result shows that it is more urgent to improve the radiation hardness of transmitter, and the introduction of local laser is a considerable method to reduce gamma radiation impact on system performance.

Performance comparison of analogue inter‐satellite microwave photonics link using intensity modulation with direct detection and phase modulation with interferometric detection

The performance of optical inter-satellite communications using microwave photonics technologies employing intensity modulation with direct detection (IMDD) and phase modulation (PM) with interferometric detection are investigated and demonstrated with a numerical example. The theoretical model considering the saturated gain and amplifier spontaneous emission noise of optical booster amplifier and optical preamplifier is constructed for both architectures. Furthermore, the authors compare the performance of PM with interferometric detection to optimum biased IMDD in terms of radio frequency (RF) gain, RF noise figure and compression dynamic range (CDR). The numerical results show that the PM with interferometric detection can achieve better RF gain, RF noise figure and CDR than the optimum biased IMDD link as the laser output power is lower than 14.34, 12.45 and 4.2 dBm, respectively.

Packet error rate analysis of digital pulse interval modulation in intersatellite optical communication systems with diversified wavefront deformation.

Diversified wavefront deformation is an inevitable phenomenon in intersatellite optical communication systems, which will decrease system performance. In this paper, we investigate the description of wavefront deformation and its influence on the packet error rate (PER) of digital pulse interval modulation (DPIM). With the wavelet method, the diversified wavefront deformation can be described by wavelet parameters: coefficient, dilation, and shift factors, where the coefficient factor represents the depth, dilation factor represents the area, and shift factor is for location. Based on this, the relationship between PER and wavelet parameters is analyzed from a theoretical viewpoint. Numerical results illustrate the validity of theoretical analysis: PER increases with the depth and area and decreases if location gets farther from the center of the optical antenna. In addition to describing diversified deformation, the advantage of the wavelet method over Zernike polynomials in computational complexity is shown via numerical example. This work provides a feasible method for the description along with influence analysis of diversified wavefront deformation from a practical viewpoint and will be helpful for designing optical systems.

Modeling and Performance Analysis of DWDM based 100 Gbps Inter-satellite Optical Wireless Communication (IsOWC) System

Modeling and Performance Analysis of DWDM based 100 Gbps Inter-satellite Optical Wireless Communication (IsOWC) System

星间光通信链路稳定保持时间估算

星间光通信链路稳定保持时间估算

Comparative Analysis of Inter Satellite Optical Wireless Channel for NRZ and RZ Modulation Formats for Different Levels of Input Power

Abstract Integration of DWDM in Optical wireless communication has undoubtedly revolutionized the satellite communication systems for use in the coming future. Thus OWC systems have become popular due to their outstanding performance uniqueness. This paper looks into the performance of Inter Satellite Optical Wireless Communication system link using DWDM multiplexing technique for long distance transmission. The Inter satellite link has been modeled at a data rate of 10 Gbps for communication range of 5000 kilometers. Furthermore, it demonstrates a comparative analysis of RZ (Return to zero) and NRZ (Non-return to zero) modulation formats by varying the levels of input power.

星间光通信中跟瞄误差下最优光束发散角设计

星间光通信中跟瞄误差下最优光束发散角设计

Simplified solution for osculating Keplerian parameter corrections of GEO satellites for intersatellite optical link

In intersatellite optical communication, the Pointing, Acquisition and Tracking (PAT) phase is one of the important phases that needs to be completed successfully before initiating communication. In this paper, we focused on correcting the possible errors on the Geostationary Earth Orbit (GEO) by using azimuth and elevation errors between Low Earth Orbit (LEO) to GEO optical link during the PAT phase. To minimise the PAT duration, a simplified correction of longitude and inclination errors of the GEO satellite’s osculating Keplerian parameters has been suggested. A simulation has been done considering the beaconless tracking and spiral-scanning technique. As a result, starting from the second day, we are able to reduce the uncertainty cone of the GEO satellite by about 200μrad, if the values are larger than that quantity. The first day of the LEO–GEO links have been used to determine the parameters. Thanks to the corrections, the locking time onto the GEO satellite has been reduced, and more data are able to transmit to the GEO satellite.

An approach to remove the background light based on linearly polarized light in the inter-satellite optical communications

In the inter-satellite optical communications, background light is an important factor that worsens the acquisition performance and tracking precision of the system. In general, optical filters are applied in eliminating background light. But the bandwidth of the optical filter is a bottleneck for improving the performance of the optical system further. We propose a new method for decreasing background light, in which linearly polarized light is employed as the beacon light. The theoretical model of acquisition probability is derived. Contrastive analysis is performed, among the system with the pure optical filter, the system using the linearly polarized light and the system with the circularly polarized light. Numerical simulations and experimental verification lead to the conclusion that acquisition probability of the system with linearly polarized light is greater than that of the other systems, and this approach is effective. This work can benefit the design of inter-satellite optical communication system.

Background light reduction method with a double phase conjugate mirror and a phase plate for optical inter-satellite communications

In optical intersatellite communication, the background light consisting mainly of sunlight decrease transmission rate with increasing bit error. A spatial filtering system using a double-phase-conjugate mirror (DPCM) and a phase plate is proposed to block the background light, which cannot be filtered out by using wavelength filters, polarization filters, or dousers. In this system, the effect of wavefront distortion caused by the phase plate and the compensation effect of the distortion by phase conjugate light from the DPCM are effectively combined for spatially separating signal light and background light. We demonstrated the reduction of the background light by the proposed system and optimized the phase plate for maximizing this reduction effect. As a result, it was clarified that the transmission rate can be drastically improved up to 11-fold.

Dynamically reconfigurable characteristics of a double phase conjugate mirror using Sn2P2S6 crystals and their application to optical inter-satellite communication

A double phase conjugate mirror (DPCM), created by two mutually incoherent beams entering photorefractive nonlinear materials, can generate a phase conjugate beam whose reflectivity may be greater than 100%. Even though the conditions of the incident beams are changed, the DPCM can be dynamically reconfigured by using a Sn2P2S6 crystal with a high response speed. These features of the DPCM are advantageous, particularly in an optical inter-satellite communication system. In particular, use of the phase conjugate beam from the DPCM offers wavefront compensation and amplification in satellite communication. In addition, the dynamically reconfigurable DPCM using a Sn2P2S6 crystal relaxes the acquisition accuracy of the signal beam in the system. In this study, the temporal and spatial operating characteristics of the DPCM using a Sn2P2S6 crystal were first clarified. Next, an inter-satellite system based on the DPCM was proposed, and it was demonstrated that our system significantly improves the tolerance of the acquisition accuracy and tracking time.

Resources scheduling for data relay satellite with microwave and optical hybrid links based on improved niche genetic algorithm

The formation of the Space-based Information System with the technology of high performance optical inter-satellite communication and the realization of global seamless coverage and mobile terminal accessing are the necessary trend of the development of optical and microwave hybrid communication. Considering the resources, missions and restraints of data relay satellite optical and microwave hybrid links system, a model of hybrid links resources scheduling is established and a scheduling algorithm based on an improved niche genetic algorithm is put forwarded. According to the multi-user-satellite, multi-time-window, multi-class-antenna and a number of missions with priority weight, the scheduling schemes are generated randomly to begin with and evaluated with the fitness functions. To obtain an optimal scheduling result, an improved niche genetic algorithm is adopted to optimize the scheduling schemes. The simulation result reveals that a satisfactory result is obtained and the improved niche genetic algorithm has advantages in both efficiency and performance in a scenario including a relay satellite with 2 optical antennas and 1 microwave antenna for user satellites connection, 8 user satellites with 64 missions. The simulation indicates that the model and the optimization algorithm are suitable for multi-user, multi-mission and multi-class-antenna hybrid communication recourses scheduling problem.

A Piezo-Actuated High-Precision Flexible Parallel Pointing Mechanism: Conceptual Design, Development, and Experiments

A high-precision pointing mechanism for intersatellite optical communication is presented in this paper, which employs flexure hinges as the passive joints and orients its moving platform by means of six piezoelectric actuators. The proposed mechanism features submicroradian resolution and microradian repeatability within a submilliradian pointing range. A corner-filleted flexure hinge considering manufacturing tolerance with high motion accuracy and large displacement is designed based on performance analysis, and the theoretical analysis is also validated by FEA simulation and experimental testing within a 5% error margin. The parameters of the parallel mechanism are synthesized by multiobjective optimization on the basis of inverse kinematics model. Moreover, the workspace determination and the FEA analysis of the optimized mechanism are also performed. Finally, a high-precision pointing prototype is fabricated and the performance testing has been implemented, which validate the effectiveness of the proposed system.

Modeling and simulation of FBG based OCDMA-IsOWC system

Photonics have evolved from protracted fibers to dominant wireless system to look at the use of hybrid optical-wireless communication system into space technology. Inter-satellite optical wireless communication (IsOWC) systems, one of the important applications of optical-wireless communication, will be deployed in space in the near future. A significant improvement in BER at 5Gbps is achieved along with the maximum length of ISL link between the two satellites by incorporating OFDM scheme in IsOWC systems than that of conventional IsOWC systems [9]. The work is further extended in this paper to prolong the ISL link with acceptable BER at 10Gbps between two satellites in space by employing code division multiple access (CDMA) scheme due to its robustness against narrowband interference and an inherent low power spectral density. In this work, we have designed a model of FBG based CDMA-IsOWC system to establish a prolonged ISL link at data rate of 10Gbps with SNR of 20dB. Further, a comparison is also reported between our proposed FBG based CDMA-IsOWC system and OFDM-IsOWC system.

Fiber-based free-space optical coherent receiver with vibration compensation mechanism

We propose a novel fiber-based free-space optical (FSO) coherent receiver for inter-satellite communication. The receiver takes advantage of established fiber-optic components and utilizes the fine-pointing subsystem installed in FSO terminals to minimize the influence of satellite platform vibrations. The received beam is coupled to a single-mode fiber, and the coupling efficiency of the system is investigated both analytically and experimentally. A receiving sensitivity of -38 dBm is obtained at the forward error correction limit with a transmission rate of 22.4 Gbit/s. The proposed receiver is shown to be a promising component for inter-satellite optical communication.