Dispersion compensated fibers with advanced modulation schemes in optical fiber communication system
01 Jan 2013-
TL;DR: In this paper, a comprehensive study of the various modulation techniques has been discussed which helps to increase data rate, to overcome dispersion effects and various non-linear effects in the fibre.
Abstract: A comprehensive study of the various modulation techniques has been discussed which helps to increase data rate, to overcome dispersion effects and various non-linear effects in the fibre. Modulation formats such as OOK (On Off Keying), BPSK (Binary Phase Shift Keying), DPSK (Differential Phase Shift Keying), DP-QPSK (Dual Polarized Quadrature Phase Shift Keying) and duobinary are studied. The DP-QPSK, DPSK and other higher modulation formats yield to better performance. Issues related to spectral efficiency, optical bandwidth, Wavelength Division Multiplexing (WDM) have also been discussed. Duobinary modulation has also stimulated much interest, especially as a practical alternative for high-spectral efficiency 40 GB/s systems alongside the more popular differential phase-shift keying (DPSK) technique. Both duobinary and DPSK can achieve the high-spectral efficiency necessary to transmit 40 GB/s data on 50GHz channel spacing. DPSK is known to have the better optical signal-to-noise ratio (OSNR) sensitivity, while duobinary is famed for a good tolerance to chromatic dispersion, and narrow optical filtering. Comparison of pulse shapes RZ and NRZ are done for DP- QPSK schemes which show that RZ has better performance. An experimental study of pulse shapes for duobinary systems is also done. The RZ versus NRZ pulse shape is compared for duobinary systems that are dominated by ASE noise, fibre chromatic dispersion, and SPM nonlinearity. Surprisingly, and in stark contrast to the case of OOK, in all cases that were considered, the NRZ pulse shape is found to be superior to RZ for duobinary transmission. An analysis of the performance limitations of SMF due to SPM effect is discussed. With the aid of OptSim simulation software a DCF has been employed with proper variation in length to tackle the nonlinear effects in the transmission system. Better performance was shown when a combination of SMF length 85 km and DCF length 15 km was chosen for total 100km fiber length. The BER and eye diagram technique have been used for evaluating the system performance.
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01 Oct 1977
TL;DR: In this paper, the basic requirements for practical optical communication systems are reviewed and the construction and performance of some of the key components such as the fibre, cable, sources, connectors and splices are discussed.
Abstract: The basic requirements for practical optical communication systems are reviewed. The construction and performance of some of the key constituents such as the fibre, cable, sources, connectors and splices are discussed. Particular emphasis is placed on the special properties of optical communication systems such as the economic advantage of wideband trunk communication, the immunity to electrical interference, and the high strength to weight ratio of the transmission medium. Details of a repeated 140 Mbit/s field demonstration over a 9 km route between Hitchin and Stevenage are given to illustrate the features of a comprehensive optical communication system.
39 citations
01 Jan 2018
TL;DR: In this article, the performance of intensity modulation based on Pulse Amplitude Modulation (PAM) under three different schemes of dispersion compensation fiber (pre, post and symmetrical) is presented.
Abstract: In this paper, study and analysis the performance of intensity modulation based on Pulse Amplitude Modulation (PAM) under three different schemes of dispersion compensation fiber (pre, post and symmetrical) is presented. The low cost proposed fiber links consists of single mode fiber connected to the one of dispersion compensation setups. Fiber dispersion plays the impact factor to limit the performance of optical link such as the length of the transmission distance. PAM format to carry (1 Gb/s) data in various lengths of single mode fiber under three configurations of dispersion. Compensation fiber is proposed to compensate the chromatic dispersion. The comparative study of the systems leads to optical modulation involving the suitable dispersion compensation configuration. The results are reported in terms of Quality Factor and Bit Error Rate. The results showed that the efficient optical communication system which is based on the symmetrical configuration has the best performance over different distances in the range of input power from (0 dBm to 10 dBm) at (1 Gb/s) data rate standard single channel optical fiber transmission system.
5 citations
01 Oct 2016
1 citations
01 Nov 2018
TL;DR: The results of this research proved that L-band could be considered as a suitable solution for 25 Gbit/s WDM-PON systems.
Abstract: The present paper aims to determine the best performing setup of 16-channel dense wavelength division multiplexed passive optical network (WDM-PON) employing two modulation formats, namely NRZ-OOK and duobinary (DB). One of the promising solutions to increase transmission system capacity and expand available bandwidth for WDM transmission system is to use optical L band. Therefore, in this paper we numerically compared the performance of 25 Gbit/s WDM-PON transmission systems operating over conventional optical C-band and extended L-band wavelengths. Dispersion compensation module with fiber Bragg grating (FBG) was implemented in both systems in order to compensate accumulated chromatic dispersion. We evaluated performance results in terms of bit error rate (BER) of received signal. The results of this research proved that L-band could be considered as a suitable solution for 25 Gbit/s WDM-PON systems.
1 citations
Cites background from "Dispersion compensated fibers with ..."
...Narrow spectrum results in the reduction of dispersion effects [9]....
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Proceedings Article•
01 Oct 2016TL;DR: It is shown, that DB is the most resistant to chromatic dispersion (CD) and is able to achieve the longest transmission distance (100 km) without dispersion compensation, and RZ-DPSK and CSRZ- DPSK modulation formats demonstrated maximal achievable reach (180 km) using DCF and EDFA.
Abstract: The present paper proposes the optimal transmission parameters for non-return-to-zero (NRZ), return-to-zero differential phase shift keying (RZ-DPSK), carrier-suppressed RZ-DPSK (CSRZ-DPSK) and duobinary (DB) modulation formats in 16-channel 10 Gbit/s wavelength division multiplexed passive optical network (WDM-PON) transmission system. The paper investigates influence of laser output power, length of dispersion compensating fiber (DCF) and application of erbium-doped fiber amplifiers (EDFA), as well as impact of optical components configuration on received signal quality. It compares demand of these modulation formats for amplification and dispersion compensation with the increase of transmission distance, determining the optimal conditions for achieving maximal network reach for each of them. It is shown, that DB is the most resistant to chromatic dispersion (CD) and is able to achieve the longest transmission distance (100 km) without dispersion compensation. Whereas RZ-DPSK and CSRZ-DPSK modulation formats demonstrated maximal achievable reach (180 km) using DCF and EDFA.
Cites background from "Dispersion compensated fibers with ..."
...SIMULATION MODEL OF 16-CHANNEL WDM-PON...
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...The DB and CSRZ-DPSK demonstrated the longer maximal transmission distance than NRZ in the system without dispersion compensating fiber (DCF)....
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References
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05 Jun 2006
TL;DR: This paper discusses the generation and detection of multigigabit/s intensity- and phase-modulated formats, and highlights their resilience to key impairments found in optical networking, such as optical amplifier noise, multipath interference, chromatic dispersion, polarization-mode dispersion.
Abstract: Fiber-optic communication systems form the high-capacity transport infrastructure that enables global broadband data services and advanced Internet applications. The desire for higher per-fiber transport capacities and, at the same time, the drive for lower costs per end-to-end transmitted information bit has led to optically routed networks with high spectral efficiencies. Among other enabling technologies, advanced optical modulation formats have become key to the design of modern wavelength division multiplexed (WDM) fiber systems. In this paper, we review optical modulation formats in the broader context of optically routed WDM networks. We discuss the generation and detection of multigigabit/s intensity- and phase-modulated formats, and highlight their resilience to key impairments found in optical networking, such as optical amplifier noise, multipath interference, chromatic dispersion, polarization-mode dispersion, WDM crosstalk, concatenated optical filtering, and fiber nonlinearity
772 citations
"Dispersion compensated fibers with ..." refers methods in this paper
...The use of higher modulation techniques reduces the required bandwidth and the same 10Gbps system can be used to achieve higher data rates [5]....
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TL;DR: In this paper, a 24-level format and an 8-level QPSK format were proposed for coherent optical communication systems, respectively, an extension and a subset of the commonly used 16-level dual-polarization (QPSK) format.
Abstract: Coherent optical transmission systems have a four-dimensional (4-D) signal space (two quadratures in two polarizations). These four dimensions can be used to create modulation formats that have a better power efficiency (higher sensitivity) than the conventional binary phase shift keying/quadrature phase shift keying (BPSK/QPSK) signals. Several examples are given, with some emphasis on a 24-level format and an 8-level format, including descriptions of how they can be realized and expressions for their symbol and bit error probabilities. These formats are, respectively, an extension and a subset of the commonly used 16-level dual-polarization QPSK format. Sphere packing simulations in 2, 3, and 4 dimensions, up to 32 levels, are used to verify their optimality. The numerical results, as the number of levels increases, are shown to agree with lattice-theoretical results. Finally, we point out that the use of these constellations will lead to improved fundamental sensitivity limits for optical communication systems, and they may also be relevant as a way of reducing power demands and/or nonlinear influence.
379 citations
"Dispersion compensated fibers with ..." refers background in this paper
...switched to give a continuous light output and the coding is achieved by means of a subsequent modulator [3], [4]....
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TL;DR: The two techniques for generating polarization-multiplexed quadrature phase-shift keying with a high spectral efficiency have the same sensitivity and SE under idealized assumptions, but it is found that CO-OFDM requires a much larger receiver bandwidth and proportionally faster speed of the analog-to-digital converters.
Abstract: We compare by simulation the performance of two techniques for generating polarization-multiplexed quadrature phase-shift keying with a high spectral efficiency (SE). The first is based on coherent optical orthogonal frequency-division multiplexing (CO-OFDM). The second, which we call Nyquist wavelength-division multiplexing (N-WDM), is based on the use of optical pulses having an “almost” rectangular spectrum, with bandwidth ideally equal to the Baud-rate. We show that the two techniques have the same sensitivity and SE under idealized assumptions. However, we found that CO-OFDM requires a much larger receiver bandwidth and proportionally faster speed of the analog-to-digital converters. We also tested CO-OFDM and N-WDM over long-haul nonlinear links and found N-WDM to outperform CO-OFDM in this case, too.
328 citations
"Dispersion compensated fibers with ..." refers background in this paper
...Differential Quadrature PhaseShift Keying splits the data stream in two, and uses DPSK to modulate each stream, then introduces a π/2 delay to one of the streams before combining them, resulting in four different phases (0, -π/2, π/2, and π)....
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...Duobinary modulation has also stimulated much interest, especially as a practical alternative for high-spectral efficiency 40 Gb/s systems alongside the more popular differential phase-shift keying (DPSK) technique....
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...Both duobinary and DPSK can achieve the high-spectral efficiency necessary to transmit 40 Gb/s data on a 50 GHz channel spacing....
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...The DP-QPSK, DPSK and other higher modulation formats yield to better performance....
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...DFB laser emits an optical carrier wave at ∼1550 nm, which is modulated in two stages to produce RZ (in one stage for NRZ) [9]....
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TL;DR: By exploiting the electromagnetic wave's four-dimensional signal space, it is found that for the additive white Gaussian noise channel, the modulation format with best sensitivity to be an 8-level format with 1.76 dB asymptotic gain over BPSK, for uncoded optical transmission with coherent detection.
Abstract: By exploiting the electromagnetic wave's four-dimensional signal space, we find that for the additive white Gaussian noise channel, the modulation format with best sensitivity to be an 8-level format with 1.76 dB asymptotic gain over BPSK, for uncoded optical transmission with coherent detection. Low-complexity modulators are presented for the format, as well as an interpretation in terms of quantum-limited sensitivity.
206 citations
"Dispersion compensated fibers with ..." refers background in this paper
...Its return-to-zero (RZ) version improves the clock recovery by making the signal return to zero in the middle of the bit period so a constant stream of ones would be represented by an alternating signal [11]....
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TL;DR: In this paper, coherent optical orthogonal frequency division multiplexing (CO-OFDM) techniques for the long-haul transmission of 100-Gb/s-class channels are described.
Abstract: This paper describes coherent optical orthogonal frequency division multiplexing (CO-OFDM) techniques for the long-haul transmission of 100-Gb/s-class channels. First, we discuss the configurations of the transmitter and receiver that implement the optical multiplexing/demultiplexing techniques for high-speed CO-OFDM transmission. Next, we review the no-guard-interval (No-GI) CO-OFDM transmission scheme which utilizes optical multiplexing for OFDM signal generation and the intradyne receiver configuration with digital signal processing (DSP). We examine the transmission characteristics of the proposed scheme, and show that No-GI CO-OFDM offers compact signal spectra and superior performance with regard to tolerance against optical amplifier noise and polarization-mode dispersion (PMD). We then introduce long-haul high-capacity transmission experiments employing No-GI CO-OFDM; 13.4 Tb/s (134 times 111 Gb/s) transmission is successfully demonstrated over 3600 km of ITU-T G.652 single-mode fiber without using optical dispersion compensation.
193 citations