In this work, we report the designing and simulative analysis of a novel 400 Gbps coherent detection-orthogonal frequency division multiplexing (CO-OFDM) based inter-satellite optical wireless communication (IsOWC) system incorporating polarization division multiplexing (PDM) for enhancing information carrying capacity of the link. The performance of the proposed system has been discussed for 4-level phase shift keying and quadrature amplitude modulation encoding schemes using signal-to-noise ratio, total received power, and constellation diagram of the received signal as performance metrics. Also, the impact of different parameters such as operating wavelength, transmission power, and receiver pointing error angle on the performance of the proposed system has been investigated. Furthermore, an enhanced detection technique for link reach enhancement has been reported in this work. Finally, the performance of the proposed CO-OFDM based IsOWC system has been compared for with and without using the PDM technique.

Modeling and Performance Analysis of 400 Gbps CO-OFDM Based Inter-satellite Optical Wireless Communication (IsOWC) System Incorporating Polarization Division Multiplexing with Enhanced Detection

In this paper, the performance analysis of the inter-satellite optical wireless communication system (IsOWC) is carried out in presence of optical space channel. Here the proposed model is a $$16 \times {100}$$
  Gbps dense multiplexed IsOWC. The dual polarized quadrature phase shift keying (DP-QPSK) modulation is used for improving the optical signal to noise ratio tolerance of the system. Further, the spectral efficiency and the receiver sensitivity is improved by incorporating the coherent orthogonal frequency division multiplexing (CO-OFDM) technique in the proposed IsOWC system. The performance of the system is evaluated by bit error rate (BER), error vector magnitude percentage, received signal power, constellation diagram. A comparative study has been carried out between different modulation techniques such as quadrature phase shift keying and DP-QPSK used in IsOWC system. It is observed that, an inter-satellite distance of 15,600 km is obtained with the proposed model at 100 Gbps for a targeted forward error correction log of BER value of − 2.42 or BER of $$3.8\times {10^{-3}}$$
 . The maximum possible data rate for different inter and intra orbit satellite has been calculated. Also, the maximum possible transceiver distance has been calculated for different data rates. The integration of two advanced technologies such as DP-QPSK modulation with CO-OFDM technique in the proposed model may impel the market demands for high bandwidth intensive and high data rate applications.

100 Gbps multiplexed inter-satellite optical wireless communication system

Inter-satellite optical wireless communication (IsOWC) links have been exploited by many researchers as a viable technology to transmit information amongst two or more satellites using optical carrier signals and outer space as the medium of propagation medium. IsOWC links can securely transmit information all over the globe. The present study discusses a spectral-efficient large-speed single-channel IsOWC system using polarization division multiplexed-quadrature phase shift keying (PDM-QPSK) scheme. Coherent detection has been used at the receiver terminal for receiver sensitivity improvement. A digital signal processing (DSP) module to mitigate losses due to nonlinearity effects and for estimating carrier phase has been used at the receiver. We have analyzed the proposed link performance by investigating the required optical signal to noise ratio (OSNR) to achieve a target bit error rate (BER). The reported results show a faithful 160 Gbit/s transmission at 40,000 km with good BER. Also, we numerically investigate the OSNR performance of link for increasing pointing errors. Further, a comparative analysis of the proposed link with previous literature illustrates a better performance in terms of spectral efficiency and figure of merit (maximum transmission range $${\times} $$
 information transmission rate). The integration of PDM-QPSK with coherent detection and DSP provides a viable platform to develop spectral-efficient IsOWC links.

Performance analysis of 160 Gbit/s single-channel PDM-QPSK based inter-satellite optical wireless communication (IsOWC) system

Inter satellite optical wireless communication (IsOWC) is an emerging transmission technology which is capable of transporting high-speed data between two satellites estranged in outer space and revolving in the same or different orbits. IsOWC links have been considered very crucial for the purpose of providing global coverage for information transmission throughout the world. This work reports the modeling and performance investigation of a novel hybrid wavelength division multiplexing–polarization division multiplexing based IsOWC transmission system incorporating an orthogonal modulation scheme combining carrier suppressed return to zero–differential quadrature phase shift keying–polarization shift keying formats to transmit three independent 40 Gbps data streams simultaneously at different signal parameters. The results show a successful transmission of 3.84 Tbps information over 58,000 km link range with acceptable Q Factor (> 6 dB) and BER (≤ 10−9) using the proposed system. The performance comparison of the proposed system with existing work has also been discussed in this paper.

Design of 3.84 Tbps hybrid WDM–PDM based inter-satellite optical wireless communication (IsOWC) system using spectral efficient orthogonal modulation scheme

A cost effective Kerr nonlinearity based spectrum sliced (SS) WDM free space optical communication system is demonstrated under different weather instabilities. The investigated supercontinuum spectrum sliced WDM FSO system is evaluated at 2.5 Gbps up to 5 km of link distance. A highly nonlinear fiber is a channel for the generation of high power broad spectrum for spectrum slicing. A dense SS-WDM is investigated at 75 GHz channel spacing among 4 channels to make system bandwidth efficient. The system is investigated for different line coding (return to zero, non return to zero) and advanced modulation format such as compressed spectrum return to zero. A major degrading factor in free space communication i.e. beam divergence is also analyzed for investigated work. Antenna diameters of receiver and transmitter play a vital role in FSO, thus various diameters performances are also studied. The approach is to cater the high-speed data demands and thus system deliberated and demonstrated from 2.5 to 10 Gbps. To strengthen the signal in this FSO system, three optical amplifiers are scrutinized such as erbium doped fiber amplifier (EDFA), semiconductor optical amplifier (SOA) and Raman amplifier in terms of bit error rate and quality factor. Results revealed that EDFA is the best amplifier in investigated SS-WDM-FSO system.

A Performance Enhancement and High Speed Spectrum Sliced Free Space Optical System

Kerr Effect Based Spectrum Sliced Wavelength Division Multiplexing For Free Space Optical Communication

Abstract Free space optics (FSO) is well-competent and premier technology to cater the high speed services in different geographical areas such as hilly areas and inter building network. In this paper, we successfully demonstrated the spectrum sliced wavelength division multiplexed FSO system. In order to make system bandwidth efficient, frequency spacing of 75 GHz is taken among the wavelength division multiplexing (WDM) channels. Carrier spectrum broadening is achieved for spectrum slicing through the nonlinearity called self-phase modulation. Moreover, requirement of multiple laser sources is eliminated. However, in conventional WDM systems, n numbers of lasers are needed to generate n WDM channels. To strengthen the signal in this FSO system, three optical amplifiers are scrutinized such as erbium-doped fiber amplifier (EDFA), semiconductor optical amplifier (SOA) and Raman amplifier in terms of Q-factor and bit error rate (BER). Results revealed that EDFA is best amplifier in proposed SS-WDM-FSO system.

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Performance Evaluation of Different Optical Amplifiers in Spectrum Sliced Free Space Optical Link

High bandwidth, low cost and small size has made Inter satellite optical wireless communication a promising and advance technology with an alternative to current microwave satellite systems. In this paper, advantages of coherent-detection quadrature phase shift keying (CO-QPSK) with DSP are investigated for the mitigation of non-linear effects. The technique of carrier phase estimation has been used to prolong the transmission range to several thousand kilometers. Further, 400 Gbps WDM-QPSK system has been analyzed for different distances with 30 dB transmitting power and 11 dB LO power. At last, system has been investigated at narrow channel spacing of 50 GHz and a brief comparison has been made with system having channel spacing of 100 GHz.

Digital Signal Processing of 400 Gbps CO-QPSK-WDM System Over Optical Wireless Channel for Carrier Phase Estimation

Abstract Free Space Optics (FSO) link exploits the tremendous network capacity and is capable of offering wireless communications similar to communications through optical fibres. However, FSO link is extremely weather dependent and the major effect on FSO links is due to adverse weather conditions like fog and snow. In this paper, an FSO link is designed using an array of receivers. The disparity of the link for very high attenuation conditions due to fog and snow is analysed using aperture averaging technique. Further effect of aperture averaging technique is investigated by comparing the systems using aperture averaging technique with systems not using aperture averaging technique. The performance of proposed model of FSO link has been evaluated in terms of Q factor, bit error rate (BER) and eye diagram.

Shaina Nagpal

Papers

Kerr Effect Based Spectrum Sliced Wavelength Division Multiplexing For Free Space Optical Communication

Performance Evaluation of Different Optical Amplifiers in Spectrum Sliced Free Space Optical Link

Digital Signal Processing of 400 Gbps CO-QPSK-WDM System Over Optical Wireless Channel for Carrier Phase Estimation

A Performance Enhancement and High Speed Spectrum Sliced Free Space Optical System

An Analytical Approach for Performance Enhancement of FSO Communication System Using Array of Receivers in Adverse Weather Conditions