Signal Regeneration Techniques Research Articles

Performance Analysis of DPSK Technique for Optical Transmission Systems

The long-distance high data rate transmission is accompanied by many transmission defects, which reduce the performance of optical communication systems. Therefore, due to the need to increase data capacity for the end user, signal regeneration techniques were used to mitigate these non-linear defects in the electric or optical field. Several techniques used to modify the optical signal, which is the possible solution to reduce the limit of non-linear transmission defects, especially before converting the signal from the optical field to the electric field. Since most of the techniques used to reduce the attenuation in the optical signal do not have the ability to reduce the error rate to reach a bit error rate (BER) less than 10-10 with a transmission capacity less than -10dBm. In this paper, the performance evaluation of DPSK has been validated for its adequate use in transmission systems. Nevertheless, the performance of the DPSK optical system was assessed to rely on a different coding format such as: Return to Zero (RZ) & Non-Return to Zero (NRZ-DPSK). The system is designed to withstand high data rate on long-distance optical transmission systems. The system investigated was simulated with OptiSystemTM 13.0 commercial software. The investigated system demonstrated the ability to mitigate nonlinear impairments from the noisy optical DPSK system with high bit-error rate (BER) improvement at low power transmission. Optical DPSK demonstrates the ability to send high-rate data transmission systems for use in the next generation of optical networks.

Modeling and design of enhanced all optical signal regeneration technique

Optical Signal regeneration in all-optical domain has played a vital in role for long haul optical communication systems. On contrary, the electronic regeneration systems have limitations in terms of real-time infeasibility for high data rate transmission with quality performance. The existing all-optical signal regeneration techniques remain in challenges for its complex design, testing and modeling prospective. The proposed all-optical signal regeneration technique is the new signal regeneration technique that is modeled and designed efficiently in order to regenerate high data rate signal that is degraded during transmission. The proposed all-optical signal regeneration technique is developed using single- pump Phase Sensitive Amplification, designed Optical Frequency Locked Model and noise mitigation model. The PSA performance is examined using various aspects i.e. signal power, noise figures, and phase error detection and correction. The proposed system will add a new dimension for signal regeneration schemes to develop more efficient regeneration systems with better performance analysis approach.

A Novel Signal Regeneration Technique for High Speed DPSK Communication Systems

In long haul communication systems, the signal regeneration is frequently used technique that provides the long reach for high-speed transmission and reception systems. During high speed and distance transmission signal fades below a definite level due to transmission impairments; Bit error rate (BER) increases rapidly that degrades the system performance. In this work, a novel signal regeneration technique is proposed for 60 Gb/s differential phase shift keying transceiver system that transmits and receives the high-speed signal over single mode fiber at transmission distance of 300 km. The designed system is modeled mathematically and its real time simulation are demonstrated. It is examined that novel proposed technique is significantly regenerating the signal for 300 km fiber length. The proposed technique has achieved the BER of 10−19 with eye open diagram in the presence of high amplitude noise, phase noise and dispersion per kilometer in optical fiber transmission. At the receiver, the proposed system has adequately mitigated the amplitude noise up to 88% and phase noise up to 89% from the transmitted signal. The proposed system will be helpful for system design engineer to design high-speed communication with required BER before its physical realization to provide quality performance for future generation high-speed communication system.

Development of New All-Optical Signal Regeneration Technique

All-optical signal regeneration have been the active research area since last decade due to evolution of nonlinear optical signal processing. Existing all-optical signal regeneration techniques are agitated in producing low Bit Error Rate (BER) of 10−10 at below than −10 dBm power received. In this paper, a new all-optical signal regeneration technique is developed by using phase sensitive amplification and designed optical phase locked signal mechanism. The developed all-optical signal regeneration technique is tested for different 10 Gb/s Differential Phase Shift Keying degraded signals. It is determined that the designed all-optical signal regeneration technique is able to provide signal regeneration with noise mitigation for degraded signals. It is analyzed that overall, for all degraded test signals, average BER of 10−13 is achieved at received power of −14 dBm. The designed technique will be helpful to enhance the performance of existing signal regeneration systems in the presence of severe noise by providing minimum BER at low received power.

A New All-Optical Signal Regeneration Technique for 10 GB/S DPSK Transmission System

<p>The transmission of high power inside the optical fiber, produce amplitude noise, phase noise and other transmission impairments that degrade the performance of optical communication system. The signal regeneration techniques are used to mitigate these nonlinear impairments in the electrical or in the optical domain. All-optical signal regeneration techniques are one of the solutions to mitigate these nonlinear transmission impairments in the optical domain without converting the signal from optical to electrical domain. The existing techniques are not capable enough to attain the Bit Error Rate (BER) less than 10<sup>-10</sup> with the power penalty less than – 9dBm. In this paper, a new all-optical signal regeneration technique is developed that mitigate amplitude and phase noises in the optical domain. The new optical signal regeneration technique is developed by combining the two existing technique one is 3R (Reshaping, Reamplification and Retiming) regeneration and other is Phase Sensitive Amplification (PSA). The 10Gb/s Differential Phase shift Keying (DPSK) noisy transmission system is used to verify the features of developed technique. The developed technique successfully mitigates the nonlinear impairments from the noisy DPSK system with significant improvement in BER at low power penalty with the additional feature of high Q-factor and an eye open response for the regenerated signal. It is determined that BER of 10<sup>-12</sup> is achieved at the power penalty of -14 dBm with Q-factor of 42 and an eye opened response. The developed technique in the DPSK system is realized using commercial software package Optisystem. The designed technique will be helpful to enhance the performance existing high-speed optical communication by achieving the minimum BER at low power penalty.</p>

Fiber-Based All-Optical Signal Regeneration

Fiber-based all-optical signal regeneration techniques are reviewed. In the first half of the paper, amplitude regeneration schemes for ON-OFF keying signals using self-phase modulation and four-wave mixing in fibers are classified and their features are described. In the second half of the paper, focus is placed on regeneration schemes of phase-encoded signals. In particular, we discuss the performance of the regenerators in which phase information is converted to/from amplitude information and noise suppression is done on the amplitude. Usefulness of phase-preserving amplitude-only regeneration in reducing nonlinear phase noise is also discussed. Some experimental results are shown. Finally, issues in applying all-optical regeneration to real transmission systems are mentioned.

A Theoretical and Experimental Study on Modulation-Format-Independent Wavelength Conversion

Modern optical networks are adopting advanced modulation formats. Future dynamic optical networks will benefit from all-optical wavelength conversion and signal regeneration techniques in support of multiple modulation formats. This paper presents a concept for a modulation-format-independent wavelength conversion technique based on an optical hybrid and an in-phase/quadrature (IQ) wavelength converter. This technique has the potential for wavelength conversion and signal regeneration of multiple modulation formats. This paper also discusses the signal distortions and noises in the semiconductor optical amplifier based IQ wavelength converter. A proof-of-principle experiment shows the wavelength conversion results of multiple modulation formats. Further, this paper presents the signal regeneration of a return-to-zero quadrature-phase-shifted-keying signal through simulation.

All optical regeneration

All-optical signal regeneration techniques are reviewed: fiber and semiconductor based devices are addressed, and some 2R and 3R signal regeneration experiments are discussed.

A signal regeneration technique for long-range propagation of dispersive Lamb waves

A technique which enables a dispersive Lamb wave to be propagated over a considerable distance to give a simple waveform at the receiver position is described. The method works by launching a signal which, by superposition of its frequency components, will recombine to form a signal with a simple shape (a pulse or tone burst) at the measurement position. The technique has been tested on thin plates both numerically and experimentally, simple windowed tone bursts being received at the measurement position even though the propagating modes were grossly dispersive. The advantage of this method in NDE applications is that the simple form of the signal received on a good plate potentially makes it easy to detect any small changes due to defects along the propagation path, and also that the signal/noise ratio is maximized at the measurement position.