Alternate Mark Inversion Research Articles

A novel dual polarization multiplexing RoF system integrating optical fiber and FSO channel with AMI downlink signals

Using dual polarization multiplexing alternate mark inversion (AMI) downlink signals, a novel radio over fiber (RoF) system integrating optical fiber and FSO channel is designed to adapt to applications in mountainous areas and other complex terrain areas. Optical heterodyne technology and self-mixing homodyne detection method are used to realize high sensitivity detection of the received signals after 25.1 km channel (including 1 km single-mode fiber and 100 m free space link) transmission. Moreover, polarization multiplexing technology is introduced to exponentially increase the transmission capacity of downlink signals. This scheme not only can be compatible with traditional optical fiber transmission systems, but also support the wireless optical access application of millimeter wave signals in RoF systems.

Bipolar alternate mark inversion encoding (BAMI) scheme for performance signature of optical transceiver systems under thermal effects

Abstract This study has clarified the bipolar alternate mark inversion encoding scheme for performance signature of optical transceiver systems under thermal effects. The light power through optical fiber channel variations with spectral wavelength at various temperature variations are clarified. The total electrical power through PIN receiver at various temperature variations are demonstrated. The electrical power amplitude, max Q Factor and min BER through PIN receiver at different temperature variations are clarified in details. Electrical and optical signal per noise ratio with laser bias current at various ambient temperatures are demonstrated. The total optical/electrical power and maximum quality signal with laser bias current at various temperature variations.

Investigation of WDM-MDM PON employing different modulation formats

Advancement in the technology and optical communication sector has led to an increase in the demands of high bit rate and bandwidth, required for reliable data transmission. To meet such demands, future generation optical networks came into existence. In this paper, we propose a 100 Gbps, 4-channel WDM-MDM PON with two input wavelengths of 1550 nm and 1555 nm and using LP 01 and LP 11 modes. The system performance has been analyzed for different internal parameters considering return-to-zero (RZ), non-return-to-zero (NRZ), alternate mark inversion (AMI) and duobinary return-to-zero (DRZ) modulation schemes. DRZ modulation outperforms the other encoding schemes resulting in achievement of an acceptable bit error rate (BER) of ≤ 10−14 over 10 km of fiber length at a 25 Gbps data rate.

Performance analysis of 40 Gb/s free space optics transmission based on orbital angular momentum multiplexed beams

This paper explores the data carrying capacity enhancement in free space optics (FSO) transmission systems by employing orbital angular momentum (OAM) multiplexing technique. Specifically, simulative investigation of OAM-FSO terrestrial transmission is carried out under varying weather conditions. A net data capacity of 40 Gb/s over free space transmission medium is demonstrated using four distinct OAM beams (LG0,0, LG0,13, LG0,40, and LG0,80). The performance is compared for alternate mark inversion (AMI), return-to-zero (RZ), and non-return-to-zero (NRZ) encoding schemes. The results showed that the best performance occurred when using NRZ modulation and a favorable 40 Gb/s transmission along a range varying from 64 to 800 m depending on the external weather conditions is reported.

4-Level Alternate-Mark-Inversion for Reach Extension in the O-Band Spectral Region

Alternate-mark-inversion (AMI) has been used in the past to improve the transmission performance of binary intensity modulation formats. In this work, we improved the tolerance of O-band 4-level pulse amplitude modulation (PAM4) transmission to channel impairments through the adoption of an AMI scheme. Improvements in receiver sensitivity were shown in both semiconductor optical amplifier (SOA) and bismuth-doped fibre amplifier (BDFA) equipped links. We confirmed the capability of 4-level AMI to extend the reach in the O-band, which was achieved through the mitigation of nonlinear and dispersive effects. We experimentally demonstrated a 4.28-dB Q-factor improvement for transmission over 60 km of SMF-28e. To offer an insight to the mechanisms leading to the improved tolerance to transmission impairments, we presented numerical simulations that illustrate the underlying method of action of AMI4.

Design of 320 Gbps hybrid AMI-PDM-WDM FSO link and its performance comparison with traditional models under diverse weather conditions

Abstract A comprehensive design is proposed for alternate mark inversion (AMI)-encoded free-space optical (FSO) communication system by hybridizing polarization division multiplexing (PDM) with wavelength division multiplexing (WDM) and its performance is investigated under diverse weather conditions. The WDM transmitter comprises eight channels transmitting 320 Gbps data over the atmospheric turbulent channel considering gamma–gamma (G–G) distribution for the FSO channel model. A PDM-WDM technique not only maximizes the link capacity of the FSO system but also enhances the spectral efficiency (SE) of the system. Besides, the proposed hybrid AMI-PDM-WDM FSO system performance is compared with the traditional AMI-WDM-PDM and AMI-WDM models to demonstrate the advantages of our proposed model for the design of FSO link. It is observed that our proposed hybrid system exhibits excellent performance under diverse weather conditions over the traditional models in terms of Q factor, received optical power, bit error rate (BER), eye diagrams and optical signal-to-noise ratio (OSNR).

Analysis of 64 channels based IS-OWC system using different intereference reduction techniques

Abstract Optical wireless communication in space is attracting great consideration due to high speed, high capacity, no EMI, high security, and wide bandwidth. OWC has edge over microwave communication because in laser based communication, relay feature saves the time of the system. In this paper, different interference reduction techniques in wavelength division multiplexing based inter-satellite optical wireless system are presented at different data rates 10, 20, and 40 Gbps. Hybrid multiplexing using wide division multiplexing and time division multiplexing is proposed first and second technique proposed is polarization interleaving in IsOWC systems. Dense channel spacing system with diverse modulations is investigated further such as Chirped, differential phase shift keying, and alternate mark inversion (AMI). Q factor is the performance evaluation parameters for different distances.

High-Speed 120 Gbps AMI-WDM-PDM Free Space Optical Transmission System

Abstract Free space optical (FSO) communication systems are gaining high popularity from the last decade due to its various advantages such as no license spectrum, low-cost implementation etc. In this work, 160 Gbps data is transmitted over 8 km FSO link by adopting alternate mark inversion (AMI), wavelength division multiplexing (WDM) and polarization division multiplexing (PDM) schemes. The results are reported in terms of Q factor, bit error rate, signal to noise ratio, total received power and eye diagrams.

Performance Comparison of Different Modulation Schemes in High-Speed MDM Based Radio Over FSO Transmission Link Under the Effect of Atmospheric Turbulence Using Aperture Averaging

In this work, we investigate the performance comparison of different modulation schemes viz. non return-to-zero (NRZ), alternate mark inversion (AMI), return-to-zero differential phase shift keying (RZ-DPSK), and non return-to-zero differential phase shift keying (NRZ-DPSK) in a 2 × 40 Gbps–40 GHz Radio over free space optics (RoFSO) transmission link incorporating mode division multiplexing (MDM) of two distinct Hermite Gaussian (HG) modes (HG00 and HG01) under the influence of different atmospheric turbulence conditions. Further, the effect of increasing receiver antenna aperture diameter on the link performance is investigated and compared for all four modulation schemes under different turbulence conditions. It is observed that as the strength of the atmospheric turbulence increases, the performance of the link degrades whereas the Bit error rate and the Quality Factor (Q Factor) of the received signal are significantly improved by increasing the receiver aperture diameter. Among the four modulation schemes, link with NRZ-DPSK modulation scheme gives the best performance under the influence of atmospheric turbulence followed by RZ-DPSK, AMI, and NRZ scheme. Also, the proposed NRZ-DPSK scheme based MDM-RoFSO link is investigated under different weather conditions and the results are compared with the previously reported works in the literature.

Performance Analysis of Duobinary and AMI Techniques Using LG Modes in Hybrid MDM-WDM-FSO Transmission System

Abstract This work is focused on transmission of duobinary and alternate mark inversion (AMI) modulation, adopting mode division multiplexing (MDM) of Laguerre Gaussian (LG) modes has been capitalized in wavelength division multiplexing (WDM) system, resulting in a 1.6 Gbps eight-channel free space optical communications (FSO) system. The simulation results show that duobinary offers better bit error rate (BER) performance compared to AMI for proposed hybrid MDM-WDM-FSO system.

Comparative analysis of capacity oriented Integrated AMI modulation technique for the deployment of radio over fiber system

To improve the spectral efficiency and to reduce non-linear distortion in the optical system, various advanced modulation techniques have been investigated for radio over fiber (RoF) system. The investigation indicates the high data rate distortion less transmission for long-haul RoF system still further investigation is required to improve spectral efficiency and to get the reduction in signal degradation. In this paper, an advanced modulation technique referred as integrated alternate mark inversion modulation technique based upon external modulation (electro-absorption modulator) has been designed and simulated. The results show better performance in terms of performance metrics i.e. Q-factor (25.15) and BER (4e−140) and also enhance the data transmission capabilities up to 100 Gbps covering the long distance of 250 km resulting a reasonable reduction in signal degradation particularly chromatic dispersion effects for long-haul transmissions.

An efficient dispersion compensating AMI–SSP technique utilizing DCF supporting 100 Gbps Radio over Fiber system

In this paper, an Alternate Mark Inversion–Symmetrical–Symmetrical-Post (AMI–SSP) dispersion compensation technique has been proposed and tested for mitigating dispersion effects in Radio over Fiber (RoF) system to improve the RoF link performance. In comparison with other existing dispersion compensation techniques, the proposed AMI–SSP technique provides better performance as the simulation is performed at a high data rate (up to 100 Gbps) covering large transmission distance (up to 700 km). Using eye diagram, it is seen that the AMI–SSP technique provides maximum eye opening, high Q-factor (11.93) and minimum BER (3.46e−33) for 100 Gbps data rate at 700 km transmission distance for the deployment of RoF system.

High Speed Radio over Fiber System for Wireless Local Area Networks by Incorporating Alternate Mark Inversion Scheme

Abstract Radio over fiber (RoF) technique has revolutionized communication industry with its high data transmission rate and ability to carry the radio signal with speed of light. It finds its application in wireless local area networks (WLANs) due to easy of deployment and low cost. This paper utilizes alternate mark inversion (AMI) technique in wave length division multiplexing (WDM) scheme to further enhance data carrying capacity of the system. It is observed that proposed AMI-WDM scheme is better technique for providing high data rates and is confirmed via SNR, Q factor and eye diagrams.

High speed MDM-Ro-FSO communication system by incorporating AMI scheme

ABSTRACTRadio over Free Space Optics (Ro-FSO) is a promising technology to provide broadband services in rural areas as next-generation communication networks. This work is focused on adopting alternate mark inversion (AMI) encoding for mode division multiplexing (MDM)-based Ro-FSO networks. Two independent channels, each carrying 2.5Gbps-10GHz data, are transmitted on Hermite Gaussian (HG) 00 and Laguerre Gaussian (LG) 00 modes over 14 km of free space optical (FSO) link.

High-speed and Long-reach Hybrid AMI–WDM–PI Inter-satellite Communication System

AbstractIn the current context of high-altitude platform communication system, inter-satellite communication is remarkable and highly effective. The present work aims to develop an integrated data transmission system incorporating alternate mark inversion, wavelength-division multiplexing, and polarization interleaving scheme for transmitting data of eight channels, each carrying 20 Gbps data over inter-satellite link of 5,000 km. The performance of the integrated data transmission of 160 Gbps data up to 5,000 km will be evaluated by means of signal-to-noise ratio, total received power, and eye diagram.

High Speed 4 × 2.5 Gbps-5 GHz AMI-WDM-RoF Transmission System for WLANs

Abstract Radio-over-fiber (RoF) is revolutionary technique to transmit radio signals over optical fiber. It can be also suitable to distribute wireless local area networks (WLANs) due to its low-cost implementation. WLANs generally operate on 5 GHz radio signals. Thus in this work, four high speed radio channels, each carrying 2.5 Gbps data and 5 GHz radio signal, are transmitted by incorporating alternate mark inversion (AMI) scheme and wavelength division multiplexing (WDM) scheme over optical fiber having span of 50 km. The performance of proposed AMI-WDM-RoF transmission system is reported in terms of Q-factor, bit error rate, signal-to-noise ratio, total received power and eye diagrams.

Influence of Transmitting Pointing Errors on High Speed WDM-AMI-Is-OWC Transmission System

AbstractInter-satellite communication is one of the revolutionary techniques that can be used to transmit the high speed date between satellites. However, space turbulences such as transmitting pointing errors play a significant role while designing inter-satellite communication systems. Those turbulences cause shutdown of inter-satellite link due to increase of attenuation during data transmission through link. The present work aims to develop an integrated data transmission system incorporating alternate mark inversion (AMI), wavelength division multiplexing (WDM), and polarization interleaving (PI) scheme for transmitting data 160 Gbps over inter-satellite link of 1,000 km under the influence of space turbulences. The performance of the integrated data transmission of 160 Gbps data up to 1,000 km will be evaluated under the influence of space turbulences by means of signal to noise ratio (SNR), total received power, bit error rate and eye diagram.

Optical CDMA system using spatial AMI coding scheme and coset representative

In this paper, the utilizations of spatial alternate mark inversion (AMI) coding scheme and coset representative are investigated in time-spreading wavelength-hopping optical code division multiple access systems. The carrier hopping prime code is utilized as signature sequence whose out of phase autocorrelation is zero and the cross-correlation is at most one. Predicated upon the zero autocorrelation sidelobes property of the carrier hopping prime code, we exploit the spatial AMI coding scheme to the trellis run-length limited code from one-dimension into two-dimension. To enhance the error correcting capability of the proposed trellis code, coset representative is imposed on the trellis to further enlarge the free distance. Since the multiple access interference and beat noise are the main deteriorating factors in system performance which will bring about the error floor effect, our proposed coding scheme with larger coding gain can further effectively alleviate the adverse impacts. Aside from the multiple access interference and beat noise, some of the detrimental effects in system performance are also taken into account, which include thermal noise, shot noise and relative intensity noise.

Modulation of propagation-invariant Localized Waves for FSO communication systems

The novel concept of spatio-temporal modulation of Nyquist pulses is introduced, and the resulting wave-packets are termed Nyquist Localized Waves (LWs). Ideal Nyquist LWs belong to the generic family of LW solutions and can propagate indefinitely in unbounded media without attenuation or chromatic dispersion. The possibility of modulating Nyquist LWs for free-space optical (FSO) communication systems is demonstrated using two different modulation techniques. The first technique is on-off keying (OOK) with alternate mark inversion (AMI) coding for 1-bit per symbol transmission, and the second one is 16-ary quadrature amplitude modulation (16-QAM) for 4-bits per symbol transmission. Aspects related to the performance, detection and generation of the spatio-temporally coupled wave-packets are discussed and future research directions are outlined.

High-bandwidth generation of duobinary and alternate-mark-inversion modulation formats using SOA-based signal processing

We report on the novel all-optical generation of duobinary (DB) and alternate-mark-inversion (AMI) modulation formats at 42.6 Gb/s from an input on-off keyed signal. The modulation converter consists of two semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer gates. A detailed SOA model numerically confirms the operational principles and experimental data shows successful AMI and DB conversion at 42.6 Gb/s. We also predict that the operational bandwidth can be extended beyond 40 Gb/s by utilizing a new pattern-effect suppression scheme, and demonstrate dramatic reductions in patterning up to 160 Gb/s. We show an increasing trade-off between pattern-effect reduction and mean output power with increasing bitrate.