Gbps Bit Research Articles

Study of DWDM-ROF link nonlinear effects using direct and external ODSB modulation formats

In this paper, we study nonlinear effects in the optical communication fibers such as four wave mixing (FWM) in an integration of dense wavelength division multiplexing (DWDM) with radio over fiber (ROF). We used an optical double side band (ODSB) configuration with direct and external modulation using dual drive Mach–Zehnder modulator. A 16-DWDM-ROF link at different data rates is used for information transmission in single mode fiber. Also, the performance analysis of the proposed system under FWM effect with different parameters such as data rate, channel spacing, input power, fiber length and optical amplifier gain is presented. The results of the proposed system are evaluated based on bit error rate (BER) and maximum quality factor (Q). Results show that the external DSB modulation format has better performance rather than the direct modulation. Generally, for 10 dB input power, 100 GHz channel spacing, 10 Gbps bit rate and 20 km link, the Q is about 20 and BER is less than 10−84 for external ODSB modulation format. Also it has been shown that with increasing data transfer rates, output results such as optical signal-to-noise ratio, BER and Q are deteriorated under influence of FWM-effect.

Performance Evaluation of DPSK System with Different Combination of Hybrid Optical Amplifiers by Using Equal and Unequal Channel Spacing

AbstractThis article investigates the performance of differential phase shift key system with different hybrid optical amplifiers with equal and unequal channel spacing. The differential phase shift key signals are transmitted with equal channel spacing of 0.1 THz and unequal channel spacing of 0.05, 0.075, 0.1 and 0.15 THz at 96×20 Gbps bit rate. The maximum transmission distance of 230 km is achieved with unequal channel spacing. It is observed that the interference between adjacent channels decreases due to unequal channel spacing and gives better results than equal channel spacing in terms of bit error rate and quality factor. It is found that the maximum distance of 220 km is achieved with equal channel spacing using Raman-erbium-doped fiber amplifier hybrid amplifier.

Performance Analysis of Hybrid Optical Amplifiers for 32 Channel WDM System at 10 Gbps Bit Rate for WAN Applications

Abstract In this paper, we have simulated an optical 32 channel WDM system with 10 Gbps data rate for various hybrid amplifiers at varying lengths. Stand-alone EDFA gives better performance than other individual amplifiers but when hybrid with Raman amplifier, the performance of the WDM system is enhanced. A lot of researchers are working on the hybrid amplifiers like EDFA and Raman. In this research paper we have also included latest amplifier such as Ytterbium and Praseodymium amplifiers and the performance of the various hybrid combinations is compared. So, different hybrid amplifiers such as Raman-EDFA, EDFA-Yb, Raman-Yb, EDFA-Pr and Raman-Pr have been analyzed for performance parameters like quality factor, bit error rate, eye height and channel power. The analysis shows that EDFA-Pr has maximum Q-factor of 15.4883 at 80 km. EDFA-Pr has a maximum eye opening of 0.00534 at 80 km of length but at 120 km transmission distance EDFA-Yb shows maximum eye opening of 0.00154. Below 100 km of transmission distance, EDFA-Pr shows minimum BER value ranging from 10–54 to 10–20 but as the length is increased above 100 km EDFA-Yb shows better performance with values ranging from 10–16 to 10–09.

Performance Analysi of Jakarta Garden City Fiber To The Home Network Design Using Eye-Diagram Method

In this paper, we introduced a fiber to the home network access based on gigabit passive optical network (FTTH-GPON) in Jakarta Garden City Area. We proposed a design using google earth and optisystem. The proposed system used 2.4 Gbps bitrate for downstream and 1.2 Gbps bitrate for upstream. We looked for suitability of the proposed design with the ITU-T FTTH-GPON standard. We used the link power budget and the risetime budget method to design the access network. Based on calculation, we got the value of link power budget equal to 22 dB, the power margin equal to 3 dB and the risetime budget equal to 0.27 ns for downstream and 0.25 ns for upstream. To analyze the system performance, we used eye-diagram method to get jitter, distortion, signal to noise ratio (SNR), Q-factor, and BER. Based on the experimental result with power 5dBm and wavelenght 1490nm, we got the jitter 16.7 ps, the distortion 1.07µ a.u., the SNR 6.87, the Q-factor 21.249 and the BER 1.9 ×10-99. The result reveal that in all cases, the Jakarta Garden City FTTH-GPON design met with ITU-T standard

Cardinality enhancement utilizing Sequential Algorithm (SeQ) code in OCDMA system

Optical Code Division Multiple Access (OCDMA) has been important with increasing demand for high capacity and speed for communication in optical networks because of OCDMA technique high efficiency that can be achieved, hence fibre bandwidth is fully used. In this paper we will focus on Sequential Algorithm (SeQ) code with AND detection technique using Optisystem design tool. The result revealed SeQ code capable to eliminate Multiple Access Interference (MAI) and improve Bit Error Rate (BER), Phase Induced Intensity Noise (PIIN) and orthogonally between users in the system. From the results, SeQ shows good performance of BER and capable to accommodate 190 numbers of simultaneous users contrast with existing code. Thus, SeQ code have enhanced the system about 36% and 111% of FCC and DCS code. In addition, SeQ have good BER performance 10-25 at 155 Mbps in comparison with 622 Mbps, 1 Gbps and 2 Gbps bit rate. From the plot graph, 155 Mbps bit rate is suitable enough speed for FTTH and LAN networks. Resolution can be made based on the superior performance of SeQ code. Thus, these codes will give an opportunity in OCDMA system for better quality of service in an optical access network for future generation's usage

Simulation and Analysis of Optimum Golomb Ruler Based 2D Codes for OCDMA System

The need for high speed communications networks has led the research communities and industry to develop reliable, scalable transatlantic and transpacific fiber-optic communication links. In this paper the optimum Golomb ruler based 2D OCDMA codes has been demonstrated. An OCDMA system based on the discussed 2D codes is designed and simulated on Optisystem. The encoder and decoder structure of OCDMA system have been designed using filter and time delays. Further the performance is analysed for various parameter such as bit rate, number of users, BER (Bit Error Rate), quality factor, eye diagram and signal diagram. The system is analyzed for up to 18 users at 1 Gbps and 1.25 Gbps bit rate.

A single As2Se3 chalcogenide Highly Non-Linear Fiber (HNLF) based simultaneous all-optical half-adder and half-subtracter

In this article, a novel simultaneous all-optical half-addition and half-subtraction scheme based on exploitation of cross-gain modulation (XGM) and four-wave mixing (FWM) in parametric medium consisting of As2Se3 chalcogenide HNLF capable of operating at 100Gbps bit rate has been demonstrated. The proposed scheme does not require any type of extra assist light sources. XGM & FWM processes have been utilized for the realization of borrow (AB‾ &A‾B) & carry (A.B) outputs, respectively of the proposed all-optical half-addition and half-subtraction module. The sum/difference output of proposed half-adder has been obtained by temporally combining earlier realized borrow (AB‾ &A‾B) signals. Q-factors and extinction ratios (ER) of over 10.5 & 11.3255dB, respectively for XGM based outputs (AB‾ &A‾B) and 10.73 & 17.47dB, respectively for FWM based outputs (A.B) have been achieved.

All-Optical Half-Adder and Half-Subtracter Based on Semiconductor Optical Amplifier

In order to overcome the bit-rate limitations caused by Electronic Signal Processing, All-Optical Signal Processing is required. All-Optical Half-Adder and Half-Subtracter can serve as building blocks for All-Optical Arithmetic Logic Unit (ALU). In this paper, a demonstration of All-Optical Half-Adder and Half-Subtracter is done operating at 1 Gbps bit rate using Continuous Wave (CW) Lasers as carrier sources and two Semiconductor Optical Amplifiers (SOA) as basic active elements. One of the arithmetic functions realized by this scheme i.e. Borrow Signal (A ¯ B) exhibited Max Q-factor of 21.2046 to achieve error free operation at bit rate of 1Gbps.

Simulation of fiber to the home triple play services at 2 Gbit/s using GE-PON architecture for 56 ONUs

This paper evaluates and compares FTTH (Fiber To The Home) GEPON (Gigabit Ethernet Passive Optical Network) link design for 56 subscribers at 20km reach at 2Gbps bit rate. A 1:56 splitter is used as a PON (Passive Optical Network) element which creates communication between a Central Office to different users and. A boosting amplifier is employed before fiber length which tends to decrease BER and allows more users to accommodate. This architecture is investigated for different values of data rate from a CO (Central Office) to the PON in terms of BER (Bit Error Rate). The simulation work reports BER of 4.5246e−009 at 2Gbit/s systems for the case of 56 users and if we further increase data rate of system say 5Gbps, then we observe a sharp increase in BER. Similarly in the variation of BER with respect to transmission distance, we observe that BER shows an increase in its value as transmission distance increases.

Comparison of various dispersion compensation techniques at high bit rates using CSRZ format

In this paper, the dispersion compensation techniques are compared on the basis of eye opening, eye closure, bit error rate and Q-factor. These techniques are applied to CSRZ system, which operates at bit rates of 2.5, 5, 10, 15 and 20 Gbps bit rates. The technique using fiber Bragg grating (FBG) for dispersion compensation is the best technique as this technique gives larger values of eye opening at 10 and 20 Gbps bit rate, smaller values of eye closure at 10 and 20 Gbps, minimum value of BER at 15 Gbps and maximum value of Q-factor at 15 Gbps when compared with other techniques. The RDF technique is the next best technique since this technique gives maximum value of eye opening when other techniques give almost similar values of eye opening at 15 Gbps, minimum value of eye closure at 15 Gbps, minimum value of BER at 15 Gbps and maximum value of Q-factor at 15 Gbps when compared with other techniques. The DCF is the next best technique as this technique gives maximum and minimum values of eye opening and eye closure at 20 Gbps (next best to FBG at 20 Gbps).

Multiple access interference elimination with enhanced chromatic dispersion tolerance in SAC OCDMA

We demonstrate a direct decoding scheme to eliminate multiple access interference in optical spectral-amplitude-coded, multiple access networks. By detecting only the non-overlapping spectrums, our scheme shows a better BER of eight orders of magnitude over the conventional complementary subtraction scheme, when 16 simultaneous channels with 10Gbps bit rate per channel are transmitted over a simulated 70km dispersion-compensated fiber span. Our direct decoding technique is also tolerant to chromatic dispersion, where the maximum achievable distance of 67km was obtained in a dispersion limited system with standard 16ps/nm.km dispersion of single mode fiber.